Form 8-K

8-K — ARIZONA PUBLIC SERVICE CO

Accession: 0001104659-26-095989

Filed: 2026-08-13

Period: 2026-08-10

CIK: 0000007286

SIC: 4931 (ELECTRIC & OTHER SERVICES COMBINED)

Item: Financial Statements and Exhibits

Documents

8-K — tm2622461d5_8k.htm (Primary)

EX-1.1 — EXHIBIT 1.1 (tm2622461d5_ex1-1.htm)

EX-4.2 — EXHIBIT 4.2 (tm2622461d5_ex4-2.htm)

EX-4.4 — EXHIBIT 4.4 (tm2622461d5_ex4-4.htm)

EX-5.1 — EXHIBIT 5.1 (tm2622461d5_ex5-1.htm)

EX-99.1 — EXHIBIT 99.1 (tm2622461d5_ex99-1.htm)

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of

the

Securities Exchange Act of 1934

Date

of report (Date of earliest event reported):

August 10, 2026

Commission File

Number

Exact Name of Each Registrant as specified in its

charter; State of Incorporation; Address; and

Telephone Number

IRS Employer

Identification No.

1-8962

PINNACLE

WEST CAPITAL CORPORATION

86-0512431

(an Arizona

corporation)

400 North

Fifth Street, P.O. Box 53999

Phoenix

Arizona

85072-3999

(602)

250-1000

1-4473

ARIZONA PUBLIC SERVICE COMPANY

86-0011170

(an Arizona corporation)

400 North Fifth Street, P.O. Box 53999

Phoenix Arizona

85072-3999

(602) 250-1000

Check the appropriate box below if the Form 8-K

filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17

CFR 240.14d-2(b))

Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17

CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title

of each class

Trading

Symbol(s)

Name

of each exchange on which registered

Common

Stock

PNW

The New

York Stock Exchange

Indicate by check mark whether the registrant is

an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the

Securities Exchange Act of 1934 (17 CFR §240.12b-2).

Emerging growth

company

If an emerging growth company, indicate by check

mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting

standards provided pursuant to Section 13(a) of the Exchange Act. ¨

This combined Form 8-K is separately filed or furnished by Pinnacle

West Capital Corporation and Arizona Public Service Company. Each registrant is filing or furnishing on its own behalf all of the information

contained in this Form 8-K that relates to such registrant and, where required, its subsidiaries. Except as stated in the preceding sentence,

neither registrant is filing or furnishing any information that does not relate to such registrant, and therefore makes no representation

as to any such information.

Co-Registrant CIK

0000007286

Co-Registrant Amendment Flag

false

Co-Registrant Form Type

8-K

Co-Registrant Document Period EndDate

2026-08-10

Co-Registrant Written Communications

false

Co-Registrant Solicitating Materials

false

Co-Registrant PreCommencement Tender Offer

false

Co-Registrant PreCommencement Issuer Tender Offer

false

Co-Registrant Emerging growth company

false

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

The registrants hereby file the following Exhibits

to Registration Statement on Form S-3 (No. 333-277448 and No. 333-277448-01, which became effective on February 28,

2024).

Exhibit

No.

Description

Previously

Filed as Exhibit

Date

Filed

1.1

Underwriting Agreement dated August 10, 2026, in connection with the offering of $100,000,000 of 5.50% Notes due 2035 and $600,000,000 of 6.25% Notes due 2056

4.1

Ninth Supplemental Indenture dated as of August 15, 2005, relating to the issuance of 5.50% Notes due 2035

4.1 to APS August 22,

2005 Form 8-K Report

8/22/2005

4.2

Thirty-Fourth Supplemental Indenture relating to the issuance of $600,000,000 of 6.25% Notes due 2056

4.3

Note of 5.50% Notes due 2035

4.2 to APS August 22,

2005 Form 8-K Report

8/22/2005

4.4

Note of 6.25% Notes due 2056

5.1

Opinion of Shirley A. Baum, Senior Vice President, General Counsel and Corporate Secretary

99.1

Information relating to Item 14 of the Registration Statement on Form S-3 (No. 333-277448-01)

104

Cover Page Interactive Data File (embedded within the Inline XBRL document)

Pursuant to the requirements

of the Securities Exchange Act of 1934, each registrant has duly caused this report to be signed on its behalf by the undersigned hereunto

duly authorized.

PINNACLE WEST CAPITAL CORPORATION

(Registrant)

Dated: August 13, 2026

By: /s/ Andrew Cooper

Andrew Cooper

Senior Vice President and Chief Financial Officer

ARIZONA PUBLIC SERVICE COMPANY

(Registrant)

Dated: August 13, 2026

By: /s/ Andrew Cooper

Andrew Cooper

Senior Vice President and Chief Financial Officer

EX-1.1 — EXHIBIT 1.1

EX-1.1

Filename: tm2622461d5_ex1-1.htm · Sequence: 2

Exhibit 1.1

ARIZONA PUBLIC SERVICE COMPANY

$100,000,000 5.50% Notes due 2035

$600,000,000 6.25% Notes due 2056

UNDERWRITING AGREEMENT

August 10, 2026

Barclays Capital Inc.

745 Seventh Avenue

New York, New York 10019

BMO Capital Markets Corp.

151 West 42nd Street, 32nd Floor

New York, New York 10036

Citigroup Global Markets Inc.

388 Greenwich Street

New York, New York 10013

Morgan Stanley & Co. LLC

1585 Broadway

New York, New York 10036

PNC Capital Markets LLC

300 Fifth Avenue, Floor 10

Pittsburgh, Pennsylvania 15222

U.S. Bancorp Investments, Inc.

214 N. Tryon Street, 26th Floor

Charlotte, North Carolina 28202

As Representatives of the several Underwriters named in Exhibit A

hereto

Ladies and Gentlemen:

1.            Introduction.

Arizona Public Service Company, an Arizona corporation (the “Company”), proposes to issue and sell to Barclays Capital

Inc., BMO Capital Markets Corp., Citigroup Global Markets Inc., Morgan Stanley & Co. LLC, PNC Capital Markets LLC and U.S. Bancorp

Investments, Inc. (collectively, the “Representatives”) and the other several underwriters named in Exhibit A

hereto (collectively, and including any person substituted for any such underwriter pursuant to Section 8, the “Underwriters”)

$100,000,000 in aggregate principal amount of its 5.50% Notes due 2035 (the “Reopened 2035 Notes”) and $600,000,000 in aggregate

principal amount of its 6.25% Notes due 2056 (the “Series 2056 Notes” and, together with the Reopened 2035 Notes,

the “Securities”) to be issued under the Indenture dated as of January 15, 1998 (the “Original Indenture”)

between the Company and The Bank of New York Mellon Trust Company, N.A. (ultimate successor to The Chase Manhattan Bank), as trustee

(the “Trustee”), as amended and supplemented by one or more Supplemental Indentures between the Company and the Trustee

(each, a “Supplemental Indenture”) (the Original Indenture as amended and supplemented by such Supplemental Indentures,

including (i) in the case of the Reopened 2035 Notes, the Ninth Supplemental Indenture dated as of August 15, 2005 between

the Company and the Trustee, and (ii) in the case of the Series 2056 Notes, the Thirty-Fourth Supplemental Indenture to be

dated as of August 13, 2026 between the Company and the Trustee (such Thirty-Fourth Supplemental Indenture referred to herein as

the “Most Recent Supplemental Indenture”), referred to herein collectively as the “Indenture”). The Company

previously issued $250,000,000 aggregate principal amount of its 5.50% Notes due 2035 (the “Initial 2035 Notes”) under

the Indenture. The Reopened 2035 Notes will have identical terms (other than the issue date, the issue price and the first interest payment

date) as, and will be part of a single series with, the Initial 2035 Notes, will be fungible with the Initial 2035 Notes for U.S. federal

income tax purposes, will have the same CUSIP number as the Initial 2035 Notes, and will trade interchangeably with the Initial 2035

Notes. All obligations of the Underwriters hereunder are several and not joint.

2.            Representations

and Warranties of the Company. In connection with the offering of the Securities, the Company represents and warrants to, and agrees

with, the several Underwriters as follows (each representation, warranty or agreement relating to information in the Registration Statement

(as defined below) shall be deemed to relate only to information concerning the Company included therein):

(a)            A

registration statement on Form S-3 (Registration No. 333-277448-01) relating to the Securities has (i) been prepared by

the Company in conformity with the requirements of the Securities Act of 1933, as amended (the “Act”), and the rules and

regulations of the Securities and Exchange Commission (the “Commission”) thereunder (the “Rules and

Regulations”), (ii) been filed with the Commission under the Act and (iii) become effective under the Act. As used

in this Agreement:

(i)            “Applicable

Time” means 4:20 p.m., New York City time, on the date hereof;

(ii)           “Effective

Date” means the date as of which any part of the Registration Statement relating to the offering of the Securities is deemed

to have become effective under the Act in accordance with Rule 430B of the Rules and Regulations;

(iii)          “Issuer

Free Writing Prospectus” means each “free writing prospectus” (as defined in Rule 405 of the Rules and

Regulations) prepared by or on behalf of the Company or used or referred to by the Company in connection with the offering of the Securities;

(iv)          “Most

Recent Preliminary Prospectus” means the latest Preliminary Prospectus (as defined below), which, for purposes of this Agreement,

shall be the Preliminary Prospectus dated August 10, 2026;

(v)           “Preliminary

Prospectus” means any preliminary prospectus relating to the Securities included in the Registration Statement or filed with

the Commission pursuant to Rule 424(b) of the Rules and Regulations (including, for purposes of this definition, any documents

incorporated by reference therein as of the Applicable Time), including any preliminary prospectus supplement relating to the Securities;

(vi)          “Pricing

Disclosure Package” means, as of the Applicable Time, the Most Recent Preliminary Prospectus, together with each Issuer Free

Writing Prospectus set forth on Exhibit B hereto, if any, and the additional information set forth on Exhibit B

hereto, if any;

(vii)         “Prospectus”

means the final prospectus relating to the Securities, including any prospectus supplement thereto relating to the Securities, as filed

with the Commission pursuant to Rule 424(b) of the Rules and Regulations; and

(viii)        “Registration

Statement” means, collectively, the various parts of such registration statement, each as amended as of the Effective Date

for such part, including any Preliminary Prospectus or the Prospectus and all exhibits to such registration statement.

Any reference to any Preliminary Prospectus (including

the Most Recent Preliminary Prospectus) or the Prospectus shall be deemed to include any documents incorporated by reference therein

pursuant to Form S-3 under the Act as of the date of such Preliminary Prospectus or the Prospectus, as the case may be. Any reference

to any amendment or supplement to any Preliminary Prospectus or the Prospectus shall be deemed to include any document filed under the

Securities Exchange Act of 1934, as amended (the “Exchange Act”), after the date of such Preliminary Prospectus or

the Prospectus, as the case may be, and incorporated by reference in such Preliminary Prospectus or the Prospectus, as the case may be.

The Commission has not issued any order preventing or suspending the use of any Preliminary Prospectus or the Prospectus or suspending

the effectiveness of the Registration Statement, and, to the knowledge of the Company, no proceeding or examination for such purpose

or pursuant to Section 8A of the Act against the Company or related to the offering has been instituted or threatened by the Commission.

The Commission has not notified the Company of any objection to the use of the form of the Registration Statement.

(b)            The

Company was at the time of the initial filing of the Registration Statement, has been at all relevant determination dates thereafter

(as provided in clause (2) of the definition of “well-known seasoned issuer” in Rule 405 of the Rules and

Regulations), is on the date hereof and will be on the Closing Date (as defined below) a “well-known seasoned issuer” (as

defined in Rule 405 of the Rules and Regulations), including not having been an “ineligible issuer” (as defined

in Rule 405 of the Rules and Regulations) at any such time or date. The Registration Statement is an “automatic shelf

registration statement” (as defined in Rule 405 of the Rules and Regulations) and was filed not earlier than the date

that is three years prior to the Closing Date. The conditions for use of Form S-3, as set forth in the General Instructions thereto,

have been satisfied.

Registration Statement, on the Effective Date and the Closing Date, conformed and will conform in all material respects, and any amendments

to the Registration Statement filed after the date hereof and on or prior to the Closing Date will conform in all material respects,

when filed, to the requirements of the Act, the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”),

and the Rules and Regulations. Any Preliminary Prospectus conformed or will conform, and the Prospectus will conform, in all material

respects when filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations and on the Closing Date to

the requirements of the Act and the Rules and Regulations. The documents incorporated by reference in any Preliminary Prospectus

or the Prospectus conformed, and any further documents so incorporated will conform, when filed with the Commission, in all material

respects to the requirements of the Exchange Act and the rules and regulations of the Commission thereunder.

(d)            The

Registration Statement did not, as of the Effective Date, contain an untrue statement of a material fact or omit to state a material

fact required to be stated therein or necessary to make the statements therein not misleading; provided, that no representation

or warranty is made (i) as to information contained in or omitted from the Registration Statement in reliance upon and in conformity

with written information furnished to the Company through the Representatives by or on behalf of any Underwriter specifically for inclusion

therein, which information consists solely of the information specified in Section 7(b), or (ii) with respect to any Statement

of Eligibility (Form T-1) under the Trust Indenture Act filed as an exhibit thereto.

(e)            The

Prospectus will not, as of its date and on the Closing Date, include an untrue statement of a material fact or omit to state a material

fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

provided, that no representation or warranty is made as to information contained in or omitted from the Prospectus in reliance

upon and in conformity with written information furnished to the Company through the Representatives by or on behalf of any Underwriter

specifically for inclusion therein, which information consists solely of the information specified in Section 7(b).

(f)            The

documents incorporated by reference in any Preliminary Prospectus or the Prospectus did not, and any further documents filed and incorporated

by reference therein will not, when filed with the Commission, include an untrue statement of a material fact or omit to state a material

fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which

they were made, not misleading.

(g)            The

Pricing Disclosure Package will not, as of the Applicable Time, include an untrue statement of a material fact or omit to state a material

fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

provided, that no representation or warranty is made as to information contained in or omitted from the Pricing Disclosure Package

in reliance upon and in conformity with written information furnished to the Company through the Representatives by or on behalf of any

Underwriter specifically for inclusion therein, which information consists solely of the information specified in Section 7(b).

The Company hereby consents to the use of the Pricing Disclosure Package in connection with the sale and distribution of the Securities

by the Underwriters.

(h)            Each

Issuer Free Writing Prospectus (including, without limitation, any road show that is a free writing prospectus under Rule 433 of

the Rules and Regulations), when considered together with the Pricing Disclosure Package as of the Applicable Time, will not include

an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light

of the circumstances under which they were made, not misleading; provided, that no representation or warranty is made as to information

contained in or omitted from any Issuer Free Writing Prospectus in reliance upon and in conformity with written information furnished

to the Company through the Representatives by or on behalf of any Underwriter specifically for inclusion therein, which information consists

solely of the information specified in Section 7(b).

(i)             Each

Issuer Free Writing Prospectus conformed or will conform in all material respects to the requirements of the Act and the Rules and

Regulations on the date of first use, and the Company has complied or will comply with any filing requirements applicable to such Issuer

Free Writing Prospectus pursuant to the Rules and Regulations. The Company has not, on or prior to the date hereof, made any offer

relating to the Securities that would constitute an Issuer Free Writing Prospectus, except as set forth on Exhibit C hereto.

The Company has retained in accordance with the Rules and Regulations all Issuer Free Writing Prospectuses that were not required

to be filed pursuant to the Rules and Regulations.

(j)            The

Company has not distributed and, prior to the later of the Closing Date and completion of the distribution of the Securities, will not

distribute any offering material in connection with the offering and sale of the Securities other than any Preliminary Prospectus, the

Prospectus and each Issuer Free Writing Prospectus set forth on Exhibit C hereto or any Issuer Free Writing Prospectus to

which the Representatives have consented in accordance with Section 4(e).

(k)            The

Company is a corporation duly organized, validly existing and in good standing under the laws of the State of Arizona. The Company has

the requisite corporate power and corporate authority to conduct its business as such business is currently being conducted as described

in the Pricing Disclosure Package.

(l)             The

Company is not and, after giving effect to the offering and sale of the Securities, will not be an “investment company” or

an entity “controlled” by an “investment company”, as such terms are defined in the Investment Company Act of

1940, as amended (the “Investment Company Act”).

(m)           The

financial statements of the Company referred to, incorporated by reference or contained in the Registration Statement and the Most Recent

Preliminary Prospectus present fairly in all material respects the financial position of the Company as of the dates shown and the results

of its operations and cash flows for the periods shown, and such financial statements have been prepared in conformity with generally

accepted accounting principles in the United States applied on a consistent basis in all material respects with respect to the periods

involved as stated therein (except as disclosed therein). Any schedule included in the Registration Statement presents fairly in all

material respects the information required to be stated therein. The Company maintains systems of internal accounting controls and processes

sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific

authorizations, (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally

accepted accounting principles and (iii) assets are safeguarded from loss or unauthorized use that could have a material effect

on the financial statements of the Company.

(n)            The

Indenture, other than the Most Recent Supplemental Indenture, has been duly qualified under the Trust Indenture Act, has been duly authorized,

executed and delivered by the Company and is a valid and binding agreement of the Company, enforceable against the Company in accordance

with its terms, subject to applicable bankruptcy, insolvency or similar laws affecting creditors’ rights generally and general

principles of equity. The Most Recent Supplemental Indenture, establishing the terms of the Series 2056 Notes, has been duly authorized

by the Company and, when executed and delivered by the Company, will be duly qualified under the Trust Indenture Act and a valid and

binding agreement of the Company, enforceable against the Company in accordance with its terms, subject to applicable bankruptcy, insolvency

or similar laws affecting creditors’ rights generally and general principles of equity.

(o)            The

Securities to be issued and sold by the Company to the Underwriters hereunder have been duly and validly authorized and, when executed

and authenticated in accordance with the provisions of the Indenture and delivered against payment therefor as provided herein, will

be entitled to the benefits provided by the Indenture and will be valid and binding obligations of the Company, in each case enforceable

against the Company in accordance with their respective terms, subject to applicable bankruptcy, insolvency or similar laws affecting

creditors’ rights generally and general principles of equity, and will conform to the description of the Securities contained in

each of the Most Recent Preliminary Prospectus and the Prospectus.

(p)            The

issue and sale of the Securities by the Company, the compliance by the Company with all of the provisions of this Agreement, the Indenture

and the Securities and the performance by the Company of its obligations under this Agreement, the Indenture and the Securities will

not (i) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any

indenture or mortgage or other deed of trust, loan agreement or other agreement or instrument to which the Company is a party or by which

the Company is bound or to which any of the property or assets of the Company is subject, (ii) violate or result in a breach of

the Articles of Incorporation, as amended, or Bylaws of the Company, (iii) violate or result in a breach of any federal or state

law, rule or regulation applicable to the Company (excluding state securities and blue sky laws) or any judgment, order or decree

of any court or governmental agency or body having jurisdiction over the Company or any of its subsidiaries or any of their respective

properties or (iv) result in the creation or imposition of any lien, charge or encumbrance of any nature whatsoever upon any of

the properties or assets of the Company (except as contemplated therein), except, in the case of clause (i) and clause (iii) above,

for any such conflict, breach or violation that is not reasonably likely to have a material adverse effect on the current or future financial

condition of the Company and its consolidated subsidiaries, taken as a whole (a “Material Adverse Effect”). No consent,

approval, authorization, order, registration or qualification of or with any such court or federal or state governmental authority is

required for the issue and sale of the Securities or the consummation by the Company of the transactions contemplated by this Agreement

or the Indenture, except (w) an order of the Arizona Corporation Commission (the “ACC”) authorizing the issuance

and sale of the Securities and the execution and delivery of the Indenture on the terms and conditions in this Agreement, the Pricing

Disclosure Package and the Prospectus, which order has been granted and is in full force and effect, (x) such consents, approvals,

authorizations, registrations or qualifications as may be required under state securities or blue sky laws in connection with the purchase

and distribution of the Securities by the Underwriters, (y) the qualification of the Indenture under the Trust Indenture Act and

(z) the registration under the Act of the Securities, and in the case of clause (y) and clause (z) above, such qualification

and registration to be obtained on or prior to the Closing Date.

(q)            This

Agreement has been duly authorized, executed and delivered by the Company.

(r)            With

certain exceptions, a public service corporation is required to obtain certificates of convenience and necessity and/or certificates

of environmental compatibility from the ACC under the Arizona Revised Statutes (“A.R.S.”) Section 40-281.A and/or

A.R.S. Sections 40-360, et seq., for construction of its lines, plant, services or systems, or any extensions thereof, within the State

of Arizona, and to obtain franchises or similar consents or permits from counties and incorporated municipalities under A.R.S. Section 40-283.A

for the construction, operation and maintenance of transmission and distribution lines within the State of Arizona. The Company holds

such valid franchises, certificates of convenience and necessity, certificates of environmental compatibility, licenses, consents and

permits pursuant to such statutory provisions as are necessary with respect to the maintenance and operation of its property and business

as now conducted, except that (i) the Company from time to time makes minor extensions of its system prior to the time a related

franchise, certificate, license, consent or permit is procured, (ii) from time to time communities already being served by the Company

become incorporated and considerable time may elapse before a franchise, license, consent or permit is procured, (iii) certain franchises,

licenses, consents or permits may have expired prior to the renegotiation thereof, (iv) under A.R.S. Section 40-281.B, the

Company may extend distribution facilities into areas contiguous to its certificates of convenience and necessity not already served

by another electric utility without extending its existing certificates or obtaining new certificates, (v) certain minor defects

and exceptions may exist that, individually and in the aggregate, are not deemed material and (vi) no representation is made regarding

the geographical scope of any franchise, certificate, license, consent or permit that is not specific as to its geographical scope.

(s)            Neither

the Company nor any of its subsidiaries or, to the knowledge of the Company, any of their respective affiliates over which any of the

foregoing exercises management control (each, a “Controlled Affiliate”) or any director or officer of the Company,

any of its subsidiaries or any of their respective Controlled Affiliates (each, a “Manager”) is a Person (as defined

in Section 2(t)): (i) listed in the annex to the Executive Order (as defined in Section 2(u)) or identified pursuant to

Section 1 of the Executive Order; (ii) that is owned or controlled by, or acting for or on behalf of, any Person listed in

the annex to the Executive Order or identified pursuant to the provisions of Section 1 of the Executive Order; (iii) with whom

an Underwriter is prohibited from dealing or otherwise engaging in any transaction by any terrorism or anti-laundering law, including

the Executive Order; (iv) who commits, threatens, conspires to commit, or support “terrorism” as defined in the Executive

Order; (v) who is named as a “Specially Designated National or Blocked Person” on the most current list published by

the Office of Foreign Assets Control of the United States Department of the Treasury (“OFAC”) at its official website,

at https://www.treasury.gov/ofac/downloads/sdnlist.pdf or any replacement website or other replacement official publication of such list;

or (vi) who is owned or controlled by a Person listed above in clause (iii) or (v), and the Company, its subsidiaries and,

to the knowledge of the Company, such Controlled Affiliates are in compliance with all applicable orders, rules and regulations

of OFAC.

(t)             Neither

the Company nor any of its subsidiaries or, to the knowledge of the Company, any of their respective Controlled Affiliates or Managers:

(i) is the target of economic or financial sanctions or trade embargoes imposed, administered or enforced from time to time by OFAC

and any similar economic or financial sanctions or trade embargoes of the type described in Section 2(s), Section 2(t), Section 2(u) and

Section 2(v) and imposed, administered or enforced from time to time by the United States government, including the United

States Department of State (collectively, the “Sanctions”); (ii) is owned or controlled by, or acts on behalf

of, any individual, partnership, corporation (including a business trust), joint stock company, trust, unincorporated association, joint

venture, limited liability company or other entity, or a government or any political subdivision or agency thereof (each, a “Person”)

that is targeted by United States or multilateral economic or trade sanctions currently in force; (iii) is, or is owned or controlled

by, a Person who is located, organized or resident in a country or territory that is, or whose government is, the subject of Sanctions,

including, without limitation, the so-called Donetsk People’s Republic, the so-called Luhansk People’s Republic or any other

Covered Region of Ukraine identified pursuant to Executive Order 14065, the Crimea Region of Ukraine and the non-government controlled

areas of the Zaporizhzhia and Kherson Regions of Ukraine, Cuba, Iran, North Korea and Syria (with respect to Syria only until July 1,

2025); or (iv) is named, identified or described on any list of Persons with whom United States Persons may not conduct business,

including any such blocked persons list, designated nationals list, denied persons list, entity list, debarred party list, unverified

list, sanctions list or other such lists published or maintained by the United States, including OFAC, the United States Department of

Commerce or the United States Department of State.

(u)            None

of the Company’s or its subsidiaries’ assets constitute property of, or are beneficially owned, directly or indirectly, by

any Person that is the target of Sanctions, including, but not limited to, the International Emergency Economic Powers Act, 50 U.S.C.

§§ 1701 et seq., The Trading with the Enemy Act, 50 U.S.C. App. 1 et seq. (the “Trading With the Enemy Act”),

any of the foreign assets control regulations of the Treasury (31 C.F.R., Subtitle B, Chapter V, as amended) (the “Foreign Assets

Control Regulations”) or any enabling legislation or regulations promulgated thereunder or executive order relating thereto

(which includes, without limitation, (i) Executive Order No. 13224, effective as of September 24, 2001, and relating to

Blocking Property and Prohibiting Transactions With Persons Who Commit, Threaten to Commit, or Support Terrorism (66 Fed. Reg. 49079

(2001)) (the “Executive Order”) and (ii) the USA PATRIOT Act), if the result of such ownership would be that

the Securities would be in violation of law (“Embargoed Person”). No Embargoed Person has any interest of any nature

whatsoever in the Company if the result of such interest would be that the offering and the issuance of the Securities would be in violation

of law. The Company has not engaged in business with Embargoed Persons if the result of such business would be that the offering and

the issuance of the Securities would be in violation of law. The Company will not, directly or indirectly, use the proceeds of the Securities,

or contribute or otherwise make available such proceeds to any subsidiary, joint venture partner or other Person, (1) to fund any

activities or business of or with any Person, or in any country or territory, that, at the time of such funding, is, or whose government

is, the subject of Sanctions, or (2) in any other manner that would result in a violation of Sanctions or laws, rules and regulations

of any jurisdiction applicable to the Company or its subsidiaries from time to time concerning or relating to bribery or corruption (collectively,

the “Anti-Corruption Laws”) by any Person (including any Person holding the Securities). Neither the Company nor any

Controlled Affiliate (A) is or will become a “blocked person” as described in the Executive Order, the Trading With

the Enemy Act or the Foreign Assets Control Regulations or (B) to the knowledge of the Company, engages in any dealings or transactions,

or is otherwise associated, with any such “blocked person”. For purposes of determining whether or not a representation is

true under this Section 2(u), the Company shall not be required to make any investigation into (x) the ownership of publicly

traded stock or other publicly traded securities or (y) the beneficial ownership of any collective investment fund.

(v)            Neither

the Company nor any of its subsidiaries or, to the knowledge of the Company and its subsidiaries, any of their Managers, has failed to

comply with the United States Foreign Corrupt Practices Act, as amended from time to time, or any other applicable anti-bribery laws

or Anti-Corruption Laws, and it and they have not made, offered, promised or authorized, and will not make, offer, promise or authorize,

whether directly or indirectly, any payment, of anything of value to (i) an executive, official, employee or agent of a governmental

department, agency or instrumentality, (ii) a director, officer, employee or agent of a wholly or partially government-owned or

-controlled company or business, (iii) a political party or official thereof, or candidate for political office or (iv) an

executive, official, employee or agent of a public international organization (e.g., the International Monetary Fund or the World Bank)

(each, a “Government Official”) while knowing or having a reasonable belief that all or some portion will be used

for the purpose of: (x) influencing any act, decision or failure to act by a Government Official in his or her official capacity,

(y) inducing a Government Official to use his or her influence with a government or instrumentality to affect any act or decision

of such government or entity or (z) securing an improper advantage, in each case in order to obtain, retain or direct business.

(w)           The

interactive data in eXtensible Business Reporting Language incorporated by reference in the Registration Statement and the Prospectus

fairly presents the information called for in all material respects and has been prepared in accordance with the Commission’s rules and

guidelines applicable thereto in all material respects. The Company’s disclosure controls and procedures provide reasonable assurance

that the interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement

and the Prospectus is prepared in accordance with the Commission’s rules and guidelines applicable thereto.

(x)            Except

as disclosed in the Registration Statement, the Preliminary Prospectus and the Prospectus, the Company has no knowledge of any security

breach or other compromise of or relating to any of the Company’s or its subsidiaries’ information technology and computer

systems, networks, hardware, software, data (including the data of their respective customers, employees, suppliers and vendors and any

third party data maintained by or on behalf of them), equipment or technology (collectively, “IT Systems and Data”),

except as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect. The Company and its

subsidiaries have not been notified of, and have no knowledge of any event or condition that would reasonably be expected to result in,

any security breach or other compromise to their IT Systems and Data, except as would not, individually or in the aggregate, reasonably

be expected to have a Material Adverse Effect. The Company and its subsidiaries are presently in compliance with all applicable laws

and statutes, all judgments, orders, rules and regulations of any court or arbitrator or governmental or regulatory authority, all

internal policies and all contractual obligations relating to the privacy and security of IT Systems and Data and to the protection of

such IT Systems and Data from unauthorized use, access, misappropriation or modification, except as would not, individually or in the

aggregate, reasonably be expected to have a Material Adverse Effect. The Company and its subsidiaries have implemented backup and disaster

recovery technology consistent with industry standards and practices. The Company and its subsidiaries have policies and procedures in

place designed to ensure the integrity and security of the IT Systems and Data and comply with such policies and procedures in all material

respects.

Any certificate signed by an officer of the Company

and delivered to the Representatives (or counsel for the Underwriters) in connection with the offering of the Securities shall be deemed

a representation and warranty by the Company, as to matters covered thereby on the date of such certificate, to each Underwriter.

3.            Purchase,

Sale and Delivery of Securities. On the basis of the representations, warranties and agreements herein contained, and subject to

the terms and conditions herein set forth, the Company agrees to sell to the Underwriters, and the Underwriters agree, severally and

not jointly, to purchase from the Company, the respective aggregate principal amounts of the Securities set forth opposite the names

of the Underwriters in Exhibit A hereto at the respective purchase prices set forth therein, plus, in the case of the Reopened

2035 Notes, accrued interest from and including March 1, 2026 to but excluding the Closing Date. The time and date of delivery and

payment with respect to the Securities shall be 10:00 a.m., New York City time, on August 13, 2026 or such other time and date as

the Representatives and the Company may agree upon in writing (the “Closing Date”). It is understood that the Underwriters

will offer the Securities for sale as set forth in the Pricing Disclosure Package and the Prospectus.

The Securities to be purchased

by each Underwriter on the Closing Date shall be in global form, registered in the name of Cede & Co. and shall be delivered

by or on behalf of the Company to the Representatives, through the facilities of The Depository Trust Company (“DTC”),

for the account of the respective Underwriter, against payment by or on behalf of such Underwriter of the purchase price therefor by

wire transfer of federal (same-day) funds to the account specified by the Company to the Representatives at least 24 hours in advance.

The Company will cause any certificates representing the Securities to be made available for checking and packaging at least 24 hours

prior to the Closing Date with respect thereto at the office of DTC or its designated custodian.

4.            Covenants

of the Company. The Company covenants and agrees with each Underwriter that, with respect to the offering of the Securities:

(a)            The

Company will file any Preliminary Prospectus and the Prospectus with the Commission pursuant to and in accordance with Rule 424(b) of

the Rules and Regulations. The Company will prepare a final term sheet, containing solely a description of the Securities, in a

form approved by the Representatives and will file such final term sheet pursuant to Rule 433(d) of the Rules and Regulations

within the time required by such Rule. The Company will file all other material required to be filed by the Company with the Commission

pursuant to Rule 433(d) of the Rules and Regulations.

(b)            The

Company will advise the Representatives promptly of any proposed amendment or supplementation of the Registration Statement, any Preliminary

Prospectus, the Pricing Disclosure Package or the Prospectus that it proposes to make between the date hereof and the Closing Date (other

than any periodic report to be filed by the Company under the Exchange Act during such period). The Company will provide the Underwriters

and their counsel with a draft of such amendment or supplement prior to filing and will reasonably consider any changes proposed in writing

by counsel for the Underwriters based on legal grounds. The Company will also advise the Representatives of the institution by the Commission

of any stop order or of any order preventing or suspending the use of any Preliminary Prospectus, the Prospectus or any Issuer Free Writing

Prospectus or of the initiation or threatening of any proceeding or examination for such purpose or pursuant to Section 8A of the

Act against the Company or related to the offering known to the Company, or of any notice from the Commission objecting to the use of

the form of the Registration Statement or any post-effective amendment thereto and will use its best efforts to prevent the issuance

of any such stop order or of any order preventing the use of any Preliminary Prospectus, the Prospectus or any Issuer Free Writing Prospectus

and to obtain as soon as possible its lifting, if issued.

Company will pay the applicable Commission filing fees relating to the Securities within the time required by Rule 456(b)(1)(i) of

the Rules and Regulations.

(d)            If,

at any time when a prospectus relating to the Securities is required to be delivered under the Act (including in circumstances where

such requirement can be satisfied pursuant to Rule 172 of the Rules and Regulations), any event occurs as a result of which

the Prospectus as then amended or supplemented would include an untrue statement of a material fact, or omit to state any material fact

necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, or if

it is necessary at any time to amend or supplement the Registration Statement or the Prospectus to comply with applicable law, the Company

promptly will (i) notify the Underwriters of such event and (ii) prepare and file with the Commission an amendment or supplement

that will correct such statement or omission or an amendment that will effect such compliance. Neither the Representatives’ consent

to, nor the Underwriters’ delivery of, any such amendment or supplement shall constitute a waiver of any conditions set forth in

Section 6.

(e)            The

Company will not make any offer relating to the Securities that would constitute an Issuer Free Writing Prospectus without the prior

written consent of the Representatives except as set forth on Exhibit C hereto.

(f)            The

Company will retain in accordance with the Rules and Regulations all Issuer Free Writing Prospectuses not required to be filed pursuant

to the Rules and Regulations. If, at any time when a prospectus relating to the Securities is required to be delivered under the

Act (including in circumstances where such requirement can be satisfied pursuant to Rule 172 of the Rules and Regulations),

any events shall have occurred as a result of which any Issuer Free Writing Prospectus, as then amended or supplemented, would conflict

with the information in the Registration Statement, the Most Recent Preliminary Prospectus or the Prospectus or would include an untrue

statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the

circumstances under which they were made, not misleading, or if for any other reason it shall be necessary to amend or supplement any

Issuer Free Writing Prospectus, the Company will notify the Representatives and will amend or supplement such Issuer Free Writing Prospectus

to correct such conflict, statement or omission and the Company will comply with any filing requirements applicable to such amended or

supplemented Issuer Free Writing Prospectus in accordance with the Rules and Regulations.

(g)            As

soon as practicable, but not later than 18 months after the date hereof, the Company will make generally available to its security holders

an earning statement or statements (which need not be audited) covering a period of at least 12 months beginning after the effective

date of the Registration Statement (as defined in Rule 158(c) of the Rules and Regulations), which will satisfy the provisions

of Section 11(a) of the Act and the Rules and Regulations.

(h)            The

Company will furnish to the Underwriters or the Representatives such copies of the Registration Statement (including one copy of the

Registration Statement for the Representatives and for the counsel for the Underwriters, which is signed and includes all exhibits),

any Preliminary Prospectus, the Prospectus and any Issuer Free Writing Prospectus, and all amendments or supplements to such documents,

as may be reasonably requested by the Underwriters or the Representatives, as the case may be; provided, that the Company will

not be required to deliver documents filed by it pursuant to the Exchange Act and thereby incorporated by reference in the Prospectus.

(i)            The

Company will arrange or cooperate in arrangements for the qualification of the Securities for sale under the securities or blue sky laws

of such jurisdictions as the Representatives designate and will continue such qualifications in effect so long as required for the distribution

of the Securities; provided, that the Company shall not be required to qualify as a foreign corporation in any state, to consent

to service of process in any state other than with respect to claims arising out of the offering or sale of the Securities or to meet

other requirements deemed by it to be unduly burdensome.

(j)            The

Company agrees to pay all costs and expenses relating to the following matters: (i) the preparation, printing or reproduction and

filing with the Commission of the Registration Statement (including financial statements and exhibits thereto), each Preliminary Prospectus,

the Prospectus, each Issuer Free Writing Prospectus or any amendment or supplement to any of them; (ii) the printing (or reproduction)

and delivery (including postage, air freight charges and charges for counting and packaging) of such copies of the Registration Statement,

each Preliminary Prospectus, the Prospectus, each Issuer Free Writing Prospectus or any amendment or supplement thereto or any document

incorporated by reference therein, as may, in each case, be reasonably requested for use in connection with the offering and sale of

the Securities; (iii) any rating of the Securities by investment rating agencies; (iv) the printing (or reproduction) and delivery

of this Agreement, any blue sky memorandum and all other agreements or documents printed (or reproduced) and delivered in connection

with the offering of the Securities; (v) any registration or qualification of the Securities for offer and sale under the securities

or blue sky laws of the several states (including filing fees and the reasonable fees and expenses of counsel for the Underwriters relating

to such registration and qualification); (vi) the transportation and other expenses incurred by or on behalf of Company representatives

(other than the Underwriters) in connection with presentations to prospective purchasers of the Securities; and (vii) all other

costs and expenses incident to the performance by the Company of its obligations hereunder. It is understood, however, that, except as

provided in this Section 4(j), Section 7 and Section 8, the Underwriters will pay all of their own costs and expenses.

(k)            Prior

to the Closing Date, the Company will not offer, sell, contract to sell, pledge or otherwise dispose of, directly or indirectly, or file

with the Commission a registration statement under the Act relating to, any additional debt securities of the Company (or warrants to

purchase debt securities of the Company) that mature more than one year after the Closing Date and that are substantially similar to

the Securities, or publicly disclose the intention to make any such offer, sale, pledge, disposition or filing, without the prior written

consent of the Representatives.

(l)             During

the period of two years after the date hereof, the Company will furnish to the Representatives and, upon request, each of the other Underwriters

(i) as soon as practicable after the end of each fiscal year, a balance sheet and statements of income and changes in common stock

equity of the Company as at the end of and for such year, all in reasonable detail and certified by independent registered public accountants,

and (ii) (A) as soon as practicable after the end of each quarterly fiscal period (except for the last quarterly fiscal period

of each fiscal year), a balance sheet and statement of income of the Company as at the end of and for such period, all in reasonable

detail and certified by a principal financial or accounting officer of the Company, (B) as soon as available, a copy of each report

of the Company filed with the Commission under the Exchange Act, and (C) from time to time, such other information concerning the

Company as may reasonably be requested. So long as the Company has active subsidiaries, such financial statements will be on a consolidated

basis to the extent the accounts of the Company and its subsidiaries are consolidated. Information required to be delivered pursuant

to this provision will be deemed to have been delivered on the date on which the information has been posted on the Company’s parent’s

website at www.pinnaclewest.com or on the Commission’s public website, or at any other website accessible by the Representatives

and identified in a notice sent by the Company to the Representatives.

(m)           If,

immediately prior to the third anniversary (the “Renewal Deadline”) of the initial effective date of the Registration

Statement, any of the Securities remain unsold by the Underwriters, the Company will, prior to the Renewal Deadline, file, if it has

not already done so and is eligible to do so, a new automatic shelf registration statement relating to the Securities (in which case

the Company will provide the Representatives and counsel for the Representatives with a draft of such automatic shelf registration statement

prior to filing and will reasonably consider any changes proposed in writing by counsel for the Representatives based on legal grounds).

If at the Renewal Deadline the Company is no longer eligible to file an automatic shelf registration statement, the Company will, prior

to the Renewal Deadline, if it has not already done so, file a new shelf registration statement relating to the Securities (in which

case the Company will provide the Representatives and counsel for the Representatives with a draft of such new shelf registration statement

prior to filing and will reasonably consider any changes proposed in writing by counsel for the Representatives based on legal grounds),

and will use its best efforts to cause such registration statement to be declared effective within 60 days after the Renewal Deadline.

The Company will take all other action necessary or appropriate to permit the public offering and sale of the Securities to continue

as contemplated in the expired registration statement relating to the Securities. References in this Section 4(m) to the Registration

Statement shall include such new automatic shelf registration statement or such new shelf registration statement, as the case may be.

(n)            If

at any time when Securities remain unsold by the Underwriters the Company receives from the Commission a notice pursuant to Rule 401(g)(2) of

the Rules and Regulations or otherwise ceases to be eligible to use the automatic shelf registration statement form, the Company

will (i) promptly notify the Representatives, (ii) promptly file a new registration statement or post-effective amendment on

the proper form relating to the Securities (in which case the Company will provide the Representatives and counsel for the Representatives

with a draft of such new registration statement or post-effective amendment prior to filing and will reasonably consider any changes

proposed in writing by counsel for the Representatives based on legal grounds), (iii) use its best efforts to cause such registration

statement or post-effective amendment to be declared effective and (iv) promptly notify the Representatives of such effectiveness.

The Company will take all other action necessary or appropriate to permit the public offering and sale of the Securities to continue

as contemplated in the registration statement that was the subject of the notice pursuant to Rule 401(g)(2) of the Rules and

Regulations or for which the Company has otherwise become ineligible. References in this Section 4(n) to the Registration Statement

shall include such new registration statement or post-effective amendment, as the case may be.

(o)            The

Company shall use the net proceeds received by it from the sale of the Securities pursuant to this Agreement in the manner specified

in the Prospectus under the caption “Use of Proceeds”.

5.            Underwriter

Free Writing Prospectus. Each Underwriter hereby agrees that, except for one or more term sheets containing the information set forth

or referred to in Exhibit B hereto, it will not use, authorize use of, refer to or participate in the use of any “free

writing prospectus”, as defined in Rule 405 of the Rules and Regulations (which term includes use of any written information

furnished to the Commission by the Company and not incorporated by reference into the Registration Statement and any press release issued

by the Company), other than (i) one or more term sheets relating to the Securities that are not Issuer Free Writing Prospectuses

and that contain preliminary terms of the Securities and related customary information not inconsistent with the final term sheet filed

by the Company pursuant to Section 4(a), (ii) a free writing prospectus that is not an Issuer Free Writing Prospectus and is

not required to be filed with the Commission, (iii) a free writing prospectus that contains no “issuer information”

(as defined in Rule 433(h)(2) of the Rules and Regulations) that was not included (including through incorporation by

reference) in any Preliminary Prospectus or a previously filed Issuer Free Writing Prospectus, (iv) any Issuer Free Writing Prospectus

prepared pursuant to Section 4(a) or Section 4(e) or (v) any free writing prospectus prepared by such Underwriter

and approved by the Company in advance in writing.

6.            Conditions

of the Obligations of the Underwriters. The obligations of the several Underwriters to purchase and pay for the Securities on the

Closing Date will be subject to the accuracy of the representations and warranties on the part of the Company herein, to the accuracy

of the statements of Company officers made pursuant to the provisions hereof, to the performance by the Company of its obligations hereunder

and to the following additional conditions precedent:

(a)            On

the date hereof, the Representatives shall have received a letter in a form reasonably satisfactory to the Representatives, dated the

date hereof, of Deloitte & Touche LLP, confirming that they are independent registered public accountants within the meaning

of the Act and the applicable published Rules and Regulations thereunder and the applicable published rules and regulations

of the Public Company Accounting Oversight Board (“PCAOB”) and stating to the effect that:

(i)            in

their opinion, the financial statements and financial statement schedule audited by them and incorporated by reference in the Pricing

Disclosure Package and the Prospectus comply as to form in all material respects with the applicable accounting requirements of the Act

and the related published Rules and Regulations;

(ii)           they

have performed the procedures specified by the American Institute of Certified Public Accountants for a review of interim financial information

as described in PCAOB AU 722, Interim Financial Information, on any unaudited financial statements included in the Pricing Disclosure

Package and the Prospectus;

(iii)          on

the basis of the review referred to in clause (ii) above, a reading of the latest available interim financial statements of the

Company, inquiries of officials of the Company who have responsibility for financial and accounting matters and other specified procedures,

nothing came to their attention that caused them to believe that:

(A)            the

unaudited financial statements, if any, included in the Pricing Disclosure Package and the Prospectus do not comply as to form in all

material respects with the applicable accounting requirements of the Act and the related published Rules and Regulations or any

material modifications should be made to such unaudited financial statements and summary of earnings for them to be in conformity with

generally accepted accounting principles;

(B)            if

any unaudited “capsule” information is contained in the Pricing Disclosure Package or the Prospectus, the unaudited operating

revenues, gross income, net income and net income per share amounts or other amounts constituting such “capsule” information

and described in such letter do not agree with the corresponding amounts set forth in the unaudited financial statements or were not

determined on a basis substantially consistent with that of the corresponding amounts in the audited statements of income;

the date of the latest available balance sheet read by such accountants, or at a subsequent specified date not more than three business

days prior to the date of such letter, there was any change in the amounts of common stock, redeemable preferred stock or non-redeemable

preferred stock of the Company or any increase in long-term debt of the Company or, at the date of the most recent available unaudited

financial statements, there was any decrease in net current assets or common stock equity as compared with amounts shown in the most

recent financial statements included in the Pricing Disclosure Package and the Prospectus, except in all cases for changes, increases

or decreases that result from the declaration or payment of dividends; or

(D)            for

the period from the closing date of the latest income statement included in the Pricing Disclosure Package and the Prospectus to the

closing date of the latest available income statement read by such accountants, there were any decreases, as compared with the corresponding

period of the previous year and with the period of corresponding length ended the date of the latest income statement included in the

Pricing Disclosure Package and the Prospectus, in the amounts of total revenues or net income;

except in all cases set forth in clause

(C) and clause (D) above for changes, increases or decreases that the Pricing Disclosure Package and the Prospectus disclose

have occurred or may occur or that are described in such letter; and

(iv)            they

have compared specified dollar amounts (or percentages derived from such dollar amounts) and other financial information contained in

the Pricing Disclosure Package and the Prospectus (in each case to the extent that such dollar amounts, percentages and other financial

information are derived from the general accounting records of the Company and its subsidiaries subject to the internal controls of the

Company’s accounting system or are derived directly from such records by analysis or computation) with the results obtained from

inquiries, a reading of such general accounting records and other procedures specified in such letter and have found such dollar amounts,

percentages and other financial information to be in agreement with such results, except as otherwise specified in such letter.

All financial statements and schedules included

in material incorporated by reference into the Pricing Disclosure Package and the Prospectus shall be deemed included in the Pricing

Disclosure Package and the Prospectus for purposes of this Section 6(a).

(b)            Any

Preliminary Prospectus and the Prospectus shall have been timely filed with the Commission in accordance with Section 4(a). The

Company shall have complied with all filing requirements applicable to any Issuer Free Writing Prospectus. No stop order suspending the

effectiveness of the Registration Statement or preventing or suspending the use of the Prospectus or any Issuer Free Writing Prospectus

shall have been issued, no proceeding or examination for such purpose or pursuant to Section 8A of the Act against the Company or

related to the offering shall have been initiated or threatened by the Commission and no order directed to the adequacy of any document

incorporated by reference in any Preliminary Prospectus or the Prospectus shall have been issued. Any request of the Commission for inclusion

of additional information in the Registration Statement or the Prospectus or otherwise shall have been complied with or resolved to the

reasonable satisfaction of the Representatives. The Commission shall not have notified the Company of any objection to the use of the

form of the Registration Statement.

to the execution of this Agreement and prior to the Closing Date, (i) there shall not have occurred any change, or any development

involving a prospective change, in or affecting particularly the financial position, business or properties of the Company and its subsidiaries

taken as a whole that, in the reasonable judgment of the Representatives, materially impairs the investment quality of the Securities,

(ii) there shall not have occurred a suspension or material limitation in trading in securities generally on the New York Stock

Exchange or in the Company’s securities, (iii) there shall not have occurred, in respect of the Company’s securities,

any downgrading or withdrawal, nor shall any notice have been given in respect of the Company’s securities of any intended or potential

downgrading or withdrawal or of any review for a possible change that does not indicate the direction of the possible change, and there

shall have been no public announcement that any of the Company’s securities have been placed on CreditWatch or Watchlist or under

any similar surveillance or review, in each case with negative implications, by S&P Global Ratings, a division of S&P Global

Inc., Moody’s Investors Service, Inc. or Fitch, Inc., (iv) there shall not have occurred a general moratorium on

commercial banking activities in New York declared by either federal or State of New York authorities, (v) there shall not have

occurred any material disruption of commercial banking, settlements of securities or clearance services in the United States and (vi) there

shall not have occurred any outbreak or escalation of major hostilities in which the United States is involved, any declaration of war

by Congress or any other substantial national or international calamity or emergency if, in the judgment of the Representatives, the

effect of any such outbreak, escalation, declaration, calamity or emergency makes it impractical or inadvisable to proceed with completion

of the sale of and payment for the Securities. If the Underwriters elect not to purchase the Securities as a result of the occurrence

of one of the events specified in this Section 6(c), the Representatives will promptly notify the Company.

(d)            The

Underwriters shall have received an opinion of the General Counsel of the Company, dated the Closing Date, to the effect that:

(i)            the

Company is a corporation duly organized, validly existing and in good standing under the laws of the State of Arizona, with the requisite

corporate power and corporate authority to conduct its business as such business is currently being conducted as described in each of

the Pricing Disclosure Package and the Prospectus, and the Company is duly qualified as a foreign corporation to do business, and is

in good standing, in the States of California and New Mexico; the opinions expressed above as to the due organization, good standing

and qualification of the Company are based solely on such counsel’s review of certain certificates of governmental authorities

described in such opinion letter, copies of which have been made available to the Underwriters and their counsel, and such counsel’s

opinions with respect to such matters are rendered as of the date of such certificates and are limited accordingly;

(ii)            the

Securities have been duly authorized by all requisite corporate action on the part of the Company and have been duly executed, issued

and delivered; the Securities constitute valid and legally binding obligations of the Company entitled to the benefits provided by the

Indenture; and the Securities conform in all material respects to the description thereof in each of the Pricing Disclosure Package and

the Prospectus;

(iii)          the

Indenture has been duly qualified under the Trust Indenture Act, has been duly authorized by all requisite corporate action on the part

of the Company and has been duly executed and delivered by the Company; and the Indenture constitutes a valid, binding and enforceable

obligation of the Company;

(iv)          (a) with

certain exceptions, a public service corporation is required to obtain certificates of convenience and necessity and/or certificates

of environmental compatibility from the ACC under A.R.S. Section 40-281.A and/or A.R.S. Sections 40-360, et seq., for construction

of its lines, plant, services or systems, or any extensions thereof, within the State of Arizona, and to obtain franchises or similar

consents or permits from counties and incorporated municipalities under A.R.S. Section 40-283.A for the construction, operation

and maintenance of transmission and distribution lines within the State of Arizona; and (b) the Company holds such valid franchises,

certificates of convenience and necessity, certificates of environmental compatibility, licenses, consents and permits pursuant to such

statutory provisions as are necessary with respect to the maintenance and operation of its property and business as now conducted, except

that (u) the Company from time to time makes minor extensions of its system prior to the time a related franchise, certificate,

license, consent or permit is procured, (v) from time to time communities already being served by the Company become incorporated

and considerable time may elapse before a franchise, license, consent or permit is procured, (w) certain franchises, licenses, consents

or permits may have expired prior to the renegotiation thereof, (x) under A.R.S. Section 40-281.B, the Company may extend distribution

facilities into areas contiguous to its certificates of convenience and necessity not already served by another electric utility without

extending its existing certificates or obtaining new certificates, (y) certain minor defects and exceptions may exist that, individually

and in the aggregate, are not deemed material and (z) such counsel need not express any opinion regarding the geographical scope

of any franchise, certificate, license, consent or permit that is not specific as to its geographical scope;

(v)           the

execution, delivery and performance of this Agreement by the Company have been duly authorized by all requisite corporate action on the

part of the Company, and this Agreement has been duly executed and delivered by the Company;

(vi)          the

issue and sale of the Securities and the performance by the Company of its obligations under this Agreement, the Indenture and the Securities

do not violate or result in a breach of (a) the Articles of Incorporation, as amended, or Bylaws of the Company, (b) any judgment,

order or decree of any court or governmental agency or body having jurisdiction over the Company or (c) any federal or state law,

rule or regulation applicable to the Company (excluding state securities and blue sky laws), except, in the case of clause (b) and

clause (c) above, for any such violation or breach that is not reasonably likely to have a Material Adverse Effect;

(vii)         the

issue and sale of the Securities and the performance by the Company of its obligations under this Agreement, the Indenture and the Securities

will not cause a breach or default under (a) any agreement to which the Company is a party or by which the Company is bound that

is filed as an exhibit to the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2025, the Company’s

Quarterly Reports on Form 10-Q for the fiscal quarters ended March 31, 2026 and June 30, 2026 or the Company’s Current

Reports on Form 8-K filed since the date of filing of the above-referenced Annual Report on Form 10-K, in each case pursuant

to Item 601(b)(4), Item 601(b)(10) or Item 601(b)(99) of Regulation S-K or (b) any other indenture or mortgage or other

deed of trust, loan agreement or other agreement or instrument to which the Company is a party or by which the Company is bound or to

which any of the property or assets of the Company is subject, except, in the case of this clause (b), for any such breach or default

that is not reasonably likely to have a Material Adverse Effect (it being understood that such counsel need express no opinion as to

any breach or default (x) arising under or based upon any covenant of a financial or numerical nature or requiring computation or

(y) otherwise not ascertainable from the face of any such agreement, this Agreement or the Indenture; and it being further understood

that the opinion in clause (b) is based solely on such counsel’s personal knowledge after consultation with other lawyers

under such counsel’s supervision who are responsible for legal review of contracts);

(viii)        no

consent, approval, authorization, order, registration or qualification of or with any federal or state governmental authority is required

for the issue and sale of the Securities, the execution and delivery of the Indenture or the consummation by the Company of the transactions

contemplated by this Agreement, except (a) an order of the ACC authorizing the issuance and sale of the Securities and the execution

and delivery of the Indenture on the terms and conditions in this Agreement, the Pricing Disclosure Package and the Prospectus, which

order has been granted and is in full force and effect, (b) such consents, approvals, authorizations, registrations or qualifications

as may be required under state securities or blue sky laws, as to which laws such counsel shall not be required to express an opinion,

(c) the qualification of the Indenture under the Trust Indenture Act and (d) the registration under the Act of the Securities;

(ix)          the

statements set forth in each of the Pricing Disclosure Package and the Prospectus under the captions “Description of APS Unsecured

Debt Securities” and “Description of the Notes”, insofar as they purport to constitute a summary of the terms of the

Securities and the Indenture, are accurate and complete in all material respects;

(x)           the

Company is not, and, after giving effect to the offering and sale of the Securities, will not be, an “investment company”

or an entity “controlled” by an “investment company”, as such terms are defined in the Investment Company Act;

(xi)          to

such counsel’s knowledge, there are no legal or governmental proceedings required to be described in the Prospectus that are not

described as required, nor any contracts or documents of a character required to be described in the Registration Statement, the Pricing

Disclosure Package, or the Prospectus or to be filed as exhibits to the Registration Statement that are not described and filed as required

(it being understood that such counsel need express no opinion as to the statements of eligibility and qualification of the Trustee under

the Trust Indenture Act);

(xii)         the

Registration Statement was automatically effective upon filing; any required filing of each prospectus relating to the Securities (including

the Prospectus) pursuant to Rule 424(b) of the Rules and Regulations has been made in the manner and within the time period

required by Rule 424(b) of the Rules and Regulations; all material required to be filed by the Company pursuant to Rule 433(d) of

the Rules and Regulations has been filed with the Commission within the applicable time period prescribed for such filing by Rule 164

of the Rules and Regulations and Rule 433 of the Rules and Regulations (it being understood that such counsel need express

no opinion as to any “free writing prospectus”, as defined in Rule 405 of the Rules and Regulations, that any Underwriter

uses, authorizes the use of, refers to or participates in the use of, except for a “free writing prospectus” that is (a) permitted

by Section 5 of this Agreement and (b) required to be filed by the Company pursuant to Rule 433(d) of the Rules and

Regulations); and, to the knowledge of such counsel, no stop order suspending the effectiveness of the Registration Statement or any

notice that would prevent its use has been issued and no proceedings for that purpose have been instituted or threatened; and

(xiii)        the

Registration Statement, as of the time it became effective, and the Prospectus, as of the date of such counsel’s opinion, in each

case as amended by the Company’s Current Report on Form 8-K to be filed with the Commission on or prior to the Closing Date,

with respect to the issuance and sale of the Securities, and other than financial statements and schedules and other financial, statistical

or accounting data included or incorporated by reference therein or omitted therefrom, as to which such counsel need express no opinion,

appear on their face to be appropriately responsive in all material respects to the requirements of the Act and the Rules and Regulations;

and, although such counsel does not assume any responsibility for the accuracy, completeness or fairness of the statements or other information

contained in the Registration Statement, the Pricing Disclosure Package or the Prospectus, except as expressly provided in Section 6(d)(ii) and

Section 6(d)(ix), and has not independently verified any of such statements or other information, such counsel has no reason to

believe that (in each case excluding (a) financial statements and schedules and other financial, statistical or accounting data

included or incorporated by reference therein or omitted therefrom, (b) the Statement of Eligibility (Form T-1) of the Trustee

under the Indenture, (c) the information contained in the Pricing Disclosure Package and the Prospectus under the caption “Description

of APS Unsecured Debt Securities − Global Securities”, (d) statements in or omissions from the Registration Statement,

the Pricing Disclosure Package or the Final Prospectus based upon written information furnished to the Company by any Underwriter through

the Representatives specifically for use therein and (e) the information contained in the Pricing Disclosure Package and the Prospectus

under the caption “Certain Material United States Federal Income Tax Consequences”, as to all of which such counsel need

express no opinion):

(A)            the

Registration Statement, as of the Effective Date, contained any untrue statement of a material fact or omitted to state any material

fact required to be stated therein or necessary to make the statements therein not misleading;

(B)            the

Pricing Disclosure Package, as of the Applicable Time, included any untrue statement of a material fact or omitted to state any material

fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

Prospectus, as of its date or at the date of such counsel’s opinion, included or includes any untrue statement of a material fact

or omitted or omits to state any material fact necessary in order to make the statements therein, in the light of the circumstances under

which they were made, not misleading.

In giving such opinion, (x) such

counsel shall state that such opinion is limited to the federal laws of the United States and the law of the State of Arizona, (y) such

counsel may rely to the extent such counsel deems appropriate upon the opinion of Pillsbury Winthrop Shaw Pittman LLP, counsel for the

Underwriters, as to all matters governed by the law of the State of New York and (z) such counsel may state that such counsel’s

opinions are subject to certain customary assumptions and qualifications acceptable to the Underwriters and their counsel.

(e)            The

Underwriters shall have received an opinion of Jennings Haug Keleher McLeod Waterfall LLP, New Mexico counsel for the Company, dated

the Closing Date, to the effect that:

(i)            the

Company is duly qualified to do business as a foreign corporation, and is in good standing, in the State of New Mexico; and

(ii)            the

activities of the Company in the State of New Mexico to date do not constitute it a “public utility” as that term is defined

in the relevant laws of the State of New Mexico, and, accordingly, no public utility franchises or certificates of convenience and necessity

are necessary under New Mexico law with respect to the maintenance and operation of the Company’s property and business as now

conducted in the State of New Mexico and no approval, authorization or consent of the New Mexico Public Regulation Commission or any

other public board or body of the State of New Mexico is required for the issuance and sale of the Securities on the terms and conditions

set forth or contemplated in this Agreement, the Pricing Disclosure Package and the Prospectus or for the execution of the Most Recent

Supplemental Indenture, except as may be required under New Mexico state securities or blue sky laws, as to which laws such counsel need

express no opinion.

In giving such opinion, Jennings

Haug Keleher McLeod Waterfall LLP may rely to the extent such counsel deems appropriate upon certificates of the Company as to any factual

matters upon which any such opinions are based and may rely upon the certificates of public officials concerning the legal existence

and good standing of the Company.

(f)            The

Underwriters shall have received from Pillsbury Winthrop Shaw Pittman LLP, counsel for the Underwriters, an opinion or opinions, dated

the Closing Date, with respect to such matters as they may reasonably require, and the Company shall have furnished to such counsel such

documents as they request for the purpose of enabling them to pass upon such matters.

(g)            The

Underwriters shall have received a certificate of the President or any Vice President and a principal financial or accounting officer

of the Company, dated the Closing Date, in which such officers, to the best of their knowledge after reasonable investigation, shall

state that (i) the representations and warranties of the Company in this Agreement are true and correct as of the Closing Date,

or, where applicable, as of such other date specified in such representation and warranty, (ii) the Company has complied with all

agreements and satisfied all conditions on its part to be performed or satisfied pursuant to this Agreement at or prior to such Closing

Date, (iii) no stop order suspending the effectiveness of the Registration Statement has been issued, no proceedings or examinations

for that purpose or pursuant to Section 8A of the Act against the Company or related to the offering have been instituted or are

contemplated by the Commission and the Commission has not notified the Company of any objection to the use of the form of the Registration

Statement or any post-effective amendment thereto and (iv) subsequent to the date of the most recent financial statements in the

Most Recent Preliminary Prospectus, there has been no material adverse change in or affecting the financial condition or results of operations

of the Company and its subsidiaries, taken as a whole, other than as set forth or contemplated in the Pricing Disclosure Package.

(h)            The

Underwriters shall have received a letter of Deloitte & Touche LLP, dated the Closing Date, which meets the requirements of

Section 6(a), except that the specified date referred to in Section 6(a) will be a date not more than three days prior

to the Closing Date for the purposes of this Section 6(h).

(i)            The

Underwriters shall have received evidence that the Securities have been assigned the ratings set forth in the free writing prospectus

that contains the final terms of the Securities in the form set forth in Annex A hereto.

(j)            The

Underwriters shall have received a certificate of the Chief Financial Officer, the Vice President of Finance or the Treasurer of the

Company, dated the Closing Date, in form and substance satisfactory to the Underwriters, in which such officer shall certify as to certain

factual matters relating to the order of the ACC authorizing the issuance and sale of the Securities.

(k)            The

Company will furnish the Underwriters with such conformed copies of such opinions, certificates, letters and documents as may be reasonably

requested.

7.            Indemnification

and Contribution.

(a)            The

Company will indemnify and hold harmless each Underwriter, its directors, officers and affiliates and each person, if any, who controls

such Underwriter within the meaning of the Act against any losses, claims, damages or liabilities, joint or several, to which such Underwriter,

such directors and officers or such controlling person may become subject, under the Act or otherwise, insofar as such losses, claims,

damages or liabilities (or actions in respect thereof) arise out of or are based upon any untrue statement or alleged untrue statement

of any material fact contained in the Registration Statement, any Preliminary Prospectus, the Prospectus, any Issuer Free Writing Prospectus

or any amendment or supplement thereto, or arise out of or are based upon the omission or alleged omission to state therein a material

fact required to be stated therein or necessary to make the statements therein not misleading, and will reimburse each Underwriter, such

directors, officers and affiliates and each such controlling person for any legal or other expenses reasonably incurred by such Underwriter,

such directors, officers and affiliates or such controlling person, as incurred, in connection with investigating or defending any such

loss, claim, damage, liability or action; provided, however, that the Company will not be liable in any such case to the

extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement

or omission or alleged omission made in any of such documents in reliance upon and in conformity with written information furnished to

the Company by any Underwriter through the Representatives specifically for use therein, which information consists solely of the information

specified in Section 7(b). This indemnity agreement will be in addition to any liability that the Company may otherwise have.

(b)            Each

Underwriter will severally and not jointly indemnify and hold harmless the Company, each of its directors, each of its officers who have

signed the Registration Statement, and each person, if any, who controls the Company within the meaning of the Act, against any losses,

claims, damages or liabilities to which the Company or any such director, officer or controlling person may become subject, under the

Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon

any untrue statement or alleged untrue statement of any material fact contained in the Registration Statement, any Preliminary Prospectus,

the Prospectus, any Issuer Free Writing Prospectus or any amendment or supplement thereto, or arise out of or are based upon the omission

or the alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not

misleading, in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or

alleged omission was made in reliance upon and in conformity with written information furnished to the Company by such Underwriter through

the Representatives specifically for use therein, and will reimburse any legal or other expenses reasonably incurred, as incurred, by

the Company or any such director, officer or controlling person in connection with investigating or defending any such loss, claim, damage,

liability or action. This indemnity agreement will be in addition to any liability that such Underwriter may otherwise have. The Company

acknowledges that the statements set forth in the last paragraph of text on the cover page of the Most Recent Preliminary Prospectus

and the Prospectus and in the third paragraph, the fourth sentence of the fifth paragraph, the fifth sentence of the fifth paragraph,

the sixth paragraph, the seventh paragraph and the eighth paragraph of text under the caption “Underwriting (Conflicts of Interest)”

in the Most Recent Preliminary Prospectus and the Prospectus constitute the only information furnished in writing by or on behalf of

the several Underwriters for inclusion in the Registration Statement, any Preliminary Prospectus, the Prospectus and any Issuer Free

Writing Prospectus or any amendment or supplement thereto.

after receipt by an indemnified party under this Section 7 of notice of the commencement of any action, such indemnified party will,

if a claim in respect thereof is to be made against an indemnifying party under this Section 7, notify the indemnifying party of

the commencement thereof; provided, that the failure to notify the indemnifying party shall not relieve it from any liability

that it may have under Section 7(a) or Section 7(b) except to the extent that it has been materially prejudiced (including

through the forfeiture of substantive rights or defenses) by such failure; provided, further, that the failure to notify

the indemnifying party shall not relieve it from any liability that it may have to an indemnified party otherwise than under Section 7(a) or

Section 7(b). In case any such action is brought against any indemnified party, and it notifies the indemnifying party of the commencement

thereof, the indemnifying party will be entitled to participate therein and, to the extent that it may wish, jointly with any other indemnifying

party similarly notified, to assume the defense thereof, with counsel reasonably satisfactory to such indemnified party (who shall not,

without the consent of the indemnified party, be counsel to the indemnifying party), and, after notice from the indemnifying party to

such indemnified party of its assumption of the defense thereof, the indemnifying party will not be liable to such indemnified party

under this Section 7 for any legal or other expenses subsequently incurred by such indemnified party in connection with the defense

thereof other than reasonable costs of investigation. Notwithstanding the indemnifying party’s election to appoint counsel to represent

the indemnified party in an action, the indemnified party shall have the right to employ separate counsel (including local counsel),

and the indemnifying party shall bear the reasonable fees, costs and expenses of such separate counsel if (i) the use of counsel

chosen by the indemnifying party to represent the indemnified party would present such counsel with a conflict of interest, (ii) the

actual or potential defendants in, or targets of, any such action include both the indemnified party and the indemnifying party and the

indemnified party shall have reasonably concluded that there may be legal defenses available to it and/or other indemnified parties that

are different from or additional to those available to the indemnifying party, (iii) the indemnifying party shall not have employed

counsel reasonably satisfactory to the indemnified party to represent the indemnified party within a reasonable time after notice of

the institution of such action or (iv) the indemnifying party shall authorize the indemnified party to employ separate counsel at

the expense of the indemnifying party. It is understood that the indemnifying party shall not, in respect of the legal expenses of any

indemnified party in connection with any proceeding or related proceedings in the same jurisdiction, be liable for the fees and expenses

of more than one separate firm (in addition to any local counsel) for all such indemnified parties. Such firm shall be designated in

writing by the Representatives, in the case of parties indemnified pursuant to Section 7(a), and by the Company, in the case of

parties indemnified pursuant to Section 7(b). An indemnifying party shall not be liable for any settlement of a claim or action

effected without its written consent, which shall not be unreasonably withheld. No indemnifying party shall, without the prior written

consent of the indemnified parties, which consent shall not be unreasonably withheld, settle or compromise or consent to the entry of

any judgment with respect to any pending or threatened claim, action, suit or proceeding in respect of which indemnification or contribution

may be sought hereunder (whether or not the indemnified parties are actual or potential parties to such claim or action) unless such

settlement, compromise or consent (i) includes an unconditional release of each indemnified party from all liability arising out

of such claim, action, suit or proceeding and (ii) does not include any findings of fact or admissions of fault or culpability as

to the indemnified parties.

(d)            If

the indemnification provided for in this Section 7 is unavailable or insufficient to hold harmless an indemnified party for any

loss, claim, damage, liability or action described in Section 7(a) or Section 7(b), then each indemnifying party shall

contribute to the amount paid or payable by such indemnified party as a result of the losses, claims, damages or liabilities referred

to in Section 7(a) or Section 7(b) on the following basis: (i) if such loss, claim, damage, liability or action

arises under Section 7(a), then (A) in such proportion as is appropriate to reflect the relative benefits received by the Company

on the one hand and the Underwriters on the other hand from the offering of the Securities or (B) if the allocation provided by

clause (A) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits

referred to in clause (A) above but also the relative fault of the Company on the one hand and the Underwriters on the other hand

in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities as well as any other relevant

equitable considerations; and (ii) if such loss, claim, damage, liability or action arises under Section 7(b), then in such

proportion as is appropriate to reflect the relative fault of the Company on the one hand and the Underwriter on the other hand in connection

with the statements or omissions that resulted in such losses, claims, damages or liabilities as well as any other relevant equitable

considerations. For purposes of clause (i) above, the relative benefits received by the Company on the one hand and the Underwriters

on the other hand shall be deemed to be in the same proportion as the total net proceeds from the offering (before deducting expenses)

received by the Company bear to the total underwriting discounts and commissions received by the Underwriters. For purposes of clause

(i) and clause (ii) above, the relative fault shall be determined by reference to, among other things, whether the untrue or

alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied

by the Company or the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct

or prevent such untrue statement or omission. The Company and each of the Underwriters agree that it would not be just and equitable

if contribution pursuant to this Section 7(d) were determined by pro rata allocation or by any other method of allocation that

does not take account of the equitable considerations referred to above in this Section 7(d). The amount paid by an indemnified

party as a result of the losses, claims, damages or liabilities referred to in the first sentence of this Section 7(d) shall

be deemed to include any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending

any action or claim that is the subject of this Section 7(d). Notwithstanding the provisions of this Section 7(d), no Underwriter

shall be required to contribute any amount in excess of the amount by which the total price at which the Securities underwritten by it

and distributed to the public were offered to the public exceeds the amount of any damages that such Underwriter has otherwise been required

to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation

(within the meaning of Section 11(f) of the Act) shall be entitled to contribution from any person who was not guilty of such

fraudulent misrepresentation. The Underwriters’ obligations in this Section 7(d) to contribute are several in proportion

to their respective underwriting obligations and not joint.

8.            Default

of Underwriters; Termination by Underwriters. If any Underwriter or Underwriters default in their obligations to purchase Securities

pursuant to this Agreement and the aggregate principal amount of Securities that such defaulting Underwriter or Underwriters agreed but

failed to purchase is 10% or less of the aggregate principal amount of Securities that the Underwriters are obligated to purchase, the

Representatives (or, if there is no Representative, the Underwriters) may make arrangements satisfactory to the Company for the purchase

of such Securities by other persons, including any of the Underwriters, but if no such arrangements are made by the Closing Date the

non-defaulting Underwriters shall be obligated severally, in proportion to their respective commitments hereunder, to purchase the Securities

that such defaulting Underwriter or Underwriters agreed but failed to purchase. If any Underwriter or Underwriters so default and the

aggregate principal amount of Securities with respect to which such default or defaults occur is more than the above-described amount

and arrangements satisfactory to the remaining Underwriters and the Company for the purchase of such Securities by other persons are

not made within 36 hours after such default, this Agreement will terminate without liability on the part of any non-defaulting Underwriter

or the Company, except as provided in Section 9. In any such case, either the Representatives or the Company shall have the right

to postpone the Closing Date, but in no event for longer than seven days, in order that the required changes, if any, in the Registration

Statement and the Prospectus or in any other documents or arrangements may be effected. Nothing herein will relieve a defaulting Underwriter

from liability for its default.

If this Agreement shall be

terminated by the Underwriters because of any failure or refusal on the part of the Company to comply with the terms or to fulfill any

of the conditions of this Agreement, or if for any reason the Company shall be unable to perform its obligations under this Agreement,

the Company shall not be liable to any Underwriter or to any member of any selling group for the loss of anticipated profits from the

transactions contemplated by this Agreement. However, in such an event, the Company will reimburse the Underwriters for all out-of-pocket

expenses (including reasonable fees and disbursements of their counsel) reasonably incurred by the Underwriters in connection with this

Agreement and the offering contemplated hereunder; provided, however, that if the Securities are not delivered by or on

behalf of the Company solely as a result of the failure to satisfy the condition set forth in Section 6(c), the Company shall have

no liability to the Underwriters except as provided in Section 4(j) and Section 7.

9.            Survival

of Certain Representations and Obligations. The respective indemnities, agreements, representations, warranties and other statements

of the Company or its officers and of the Underwriters set forth in or made pursuant to this Agreement will remain in full force and

effect regardless of any investigation, or statement as to the results thereof, made by or on behalf of the Underwriters or the Company

or any of its officers or directors or any controlling person, and will survive delivery of and payment for the Securities. If this Agreement

is terminated pursuant to Section 8, or if for any reason a purchase pursuant to this Agreement is not consummated, the Company

shall remain responsible for the expenses to be paid or reimbursed by it pursuant to Section 4, and the respective obligations of

the Company and the Underwriters pursuant to Section 7 shall remain in effect.

10.          Notices.

All communications hereunder relating to any offering of Securities will be in writing, and, if sent to the Underwriters, may be mailed,

delivered or furnished by electronic communication (including fax or e-mail) and confirmed to (i) Barclays Capital Inc., 745 Seventh

Avenue, New York, New York 10019, Attention: Syndicate Registration, fax: [***], email: [***], (ii) BMO Capital Markets Corp., 151

W. 42nd Street, 32nd Floor, New York, New York 10036 Attention: Legal Department, fax: [***], email: [***], (iii) Citigroup Global

Markets Inc., 388 Greenwich Street, New York, New York 10013, Attention: General Counsel, fax: [***], email: [***], (iv) Morgan

Stanley & Co. LLC, 1585 Broadway, New York, New York 10036, Attention: Investment Banking Division, with a copy to the Legal

Department, fax: [***], email: [***], (v) PNC Capital Markets LLC, 300 Fifth Avenue, Floor 10, Pittsburgh, Pennsylvania 15222, Attention:

Debt Capital Markets, Fixed Income Transaction Execution, email: [***] and (vi) U.S. Bancorp Investments, Inc., 214 N. Tryon

Street, 26th Floor, Charlotte, North Carolina 28202, Attention: High Grade Syndicate, fax: [***], email: [***]; provided, however,

that any notice to an Underwriter pursuant to Section 7 will be mailed, delivered, faxed or emailed and confirmed to each such Underwriter

at its own address. All communications hereunder to the Company shall be mailed to the Company, Attention: Treasurer, at 400 North Fifth

Street, Mail Station 9040, Phoenix, Arizona 85004, or delivered, faxed or emailed and confirmed to the Company, at 400 North Fifth Street,

Mail Station 9040, Phoenix, Arizona 85004, fax: [***], email: [***].

11.          Successors.

This Agreement will inure to the benefit of and be binding upon the parties hereto and the Underwriter or Underwriters as are named in

Exhibit A hereto and their respective successors and the officers and directors and controlling persons referred to in Section 7,

and no other person will have any right or obligation hereunder.

12.          Representation

of Underwriters. The Representatives may act for the Underwriters in connection with the offering contemplated by this Agreement,

and any action under this Agreement taken by the Representatives will be binding upon the Underwriters.

13.          Execution

in Counterparts. This Agreement may be executed in one or more counterparts, each of which shall be deemed to be an original, but

all such respective counterparts shall together constitute a single instrument. The words “execution”, “signed”

and “signature” and words of like import in this Agreement or in any other certificate, agreement or document related to

this Agreement shall include images of manually executed signatures transmitted by facsimile or other electronic format (including, without

limitation, “pdf”, “tif” or “jpg”) and other electronic signatures (including, without limitation,

DocuSign and AdobeSign). The use of electronic signatures and electronic records (including, without limitation, any contract or other

record created, generated, sent, communicated, received or stored by electronic means) shall be of the same legal effect, validity and

enforceability as a manually executed signature or use of a paper-based record-keeping system to the fullest extent permitted by applicable

law, including, without limitation, the Electronic Signatures in Global and National Commerce Act, the New York State Electronic Signatures

and Records Act and any other applicable law, including, without limitation, any state law based on the Uniform Electronic Transactions

Act or the Uniform Commercial Code.

14.          Applicable

Law. This Agreement shall be governed by and construed in accordance with the internal laws of the State of New York.

15.          WAIVER

OF JURY TRIAL. THE COMPANY AND THE UNDERWRITERS HEREBY WAIVE THEIR RESPECTIVE RIGHTS TO JURY TRIAL WITH RESPECT TO ANY LITIGATION

ARISING UNDER, OR IN CONNECTION WITH, THIS AGREEMENT.

16.          Headings.

The headings of the sections of this Agreement have been inserted for convenience of reference only and shall not be deemed a part of

this Agreement.

17.          No

Fiduciary Duty. The Company acknowledges and agrees that in connection with this offering and sale of the Securities or any other

services the Underwriters may be deemed to be providing hereunder, notwithstanding any pre-existing relationship, advisory or otherwise,

between the parties or any oral representations or assurances previously or subsequently made by the Underwriters: (i) no fiduciary

or agency relationship between the Company and any other person, on the one hand, and the Underwriters, on the other hand, exists; (ii) the

Underwriters are not acting as advisors, expert or otherwise, to the Company, including, without limitation, with respect to the determination

of the public offering price of the Securities, and such relationship between the Company, on the one hand, and the Underwriters, on

the other hand, is entirely and solely commercial and is based on arms’-length negotiations; (iii) any duties and obligations

that the Underwriters may have to the Company shall be limited to those duties and obligations specifically stated herein; and (iv) the

Underwriters and their respective affiliates may have interests that differ from those of the Company. To the full extent allowed by

law, the Company hereby waives any claims that the Company may have against the Underwriters with respect to any breach of fiduciary

duty in connection with this offering.

18.          Recognition

of the U.S. Special Resolution Regimes. In the event that any Underwriter that is a Covered Entity (as defined below) becomes subject

to a proceeding under a U.S. Special Resolution Regime (as defined below), the transfer from such Underwriter of this Agreement, and

any interest and obligation in or under this Agreement, will be effective to the same extent as the transfer would be effective under

the U.S. Special Resolution Regime if this Agreement, and any such interest and obligation, were governed by the laws of the United States

or a state of the United States. In the event that any Underwriter that is a Covered Entity or a BHC Act Affiliate (as defined below)

of such Underwriter becomes subject to a proceeding under a U.S. Special Resolution Regime, Default Rights (as defined below) under this

Agreement that may be exercised against such Underwriter are permitted to be exercised to no greater extent than such Default Rights

could be exercised under the U.S. Special Resolution Regime if this Agreement were governed by the laws of the United States or a state

of the United States. “BHC Act Affiliate” has the meaning assigned to the term “affiliate” in, and shall

be interpreted in accordance with, 12 U.S.C. § 1841(k). “Covered Entity” means any of the following: (i) a

“covered entity” as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 252.82(b); (ii) a

“covered bank” as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 47.3(b); or (iii) a

“covered FSI” as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 382.2(b). “Default

Right” has the meaning assigned to that term in, and shall be interpreted in accordance with, 12 C.F.R. §§ 252.81,

47.2 or 382.1, as applicable. “U.S. Special Resolution Regime” means each of (x) the Federal Deposit Insurance

Act and the regulations promulgated thereunder and (y) Title II of the Dodd-Frank Wall Street Reform and Consumer Protection Act

and the regulations promulgated thereunder.

{Signature Pages Follow}

If the foregoing is in accordance

with your understanding of our agreement, kindly sign and return to us the enclosed duplicate hereof, whereupon it will become a binding

agreement between the Company and the Underwriters in accordance with its terms.

Very truly yours,

ARIZONA PUBLIC SERVICE COMPANY

By:

/s/ Chris R.

Bauer

Name: Chris R. Bauer

Title: Vice President and Treasurer

The foregoing Underwriting

Agreement is hereby confirmed and

accepted as of the date first above

written, on behalf of themselves and

the other several Underwriters named

in Exhibit A hereto.

Barclays Capital Inc.

BMO Capital Markets Corp.

Citigroup Global Markets Inc.

Morgan Stanley & Co.

LLC

PNC Capital Markets LLC

U.S. Bancorp Investments, Inc.

As Representatives of the several

Underwriters named in Exhibit A

hereto

Barclays Capital Inc.

By:

/s/ John Lembeck

Name: John Lembeck

Title: Managing Director

BMO Capital Markets Corp.

By:

/s/ Mark Spadaccini

Name: Mark Spadaccini

Title: Managing Director

{Signature Page to

Underwriting Agreement}

Citigroup Global Markets Inc.

By:

/s/ Adam D. Bordner

Name: Adam D. Bordner

Title: Managing Director

Morgan Stanley & Co. LLC

By:

/s/ Natalie Smithson

Name: Natalie Smithson

Title: Vice President

PNC Capital Markets LLC

By:

/s/ Valerie

Shadeck

Name: Valeria Shadeck

Title: Managing Director

U.S. Bancorp Investments, Inc.

By:

/s/ Brent Kreissl

Name: Brent Kreissl

Title: Managing Director

{Signature Page to Underwriting Agreement}

Exhibit A

Underwriter

Principal

Amount

of Reopened

2035

Notes

Purchase

Price

for Reopened

2035

Notes*

Principal

Amount

of Series

2056

Notes

Purchase

Price

for Series

2056

Notes**

Barclays Capital Inc.

$ 16,500,000

$ 16,336,485

$ 99,000,000

$ 97,193,250

BMO Capital Markets Corp.

$ 16,500,000

$ 16,336,485

$ 99,000,000

$ 97,193,250

Citigroup Global Markets Inc.

$ 16,500,000

$ 16,336,485

$ 99,000,000

$ 97,193,250

Morgan Stanley & Co. LLC

$ 16,500,000

$ 16,336,485

$ 99,000,000

$ 97,193,250

PNC Capital Markets LLC

$ 16,500,000

$ 16,336,485

$ 99,000,000

$ 97,193,250

U.S. Bancorp Investments, Inc.

$ 16,500,000

$ 16,336,485

$ 99,000,000

$ 97,193,250

Academy Securities, Inc.

$ 1,000,000

$ 990,090

$ 6,000,000

$ 5,890,500

Total

$ 100,000,000

$ 99,009,000

$ 600,000,000

$ 589,050,000

* Reflecting a purchase price of 99.009% of the principal amount of

the Reopened 2035 Notes, plus accrued interest from and including March 1, 2026 to but excluding the Closing Date.

** Reflecting a purchase price of 98.175% of the principal amount

of the Series 2056 Notes.

A-1

Exhibit B

Issuer Free Writing Prospectuses Included

in the Pricing Disclosure Package

· Final

Pricing Term Sheet related to the Securities attached hereto as Annex A

Additional Information

· None

B-1

Exhibit C

Issuer Free Writing Prospectuses Used by

the Company

· Final

Pricing Term Sheet related to the Securities attached hereto as Annex A

B-1

Exhibit 1.1

ANNEX A

Final Term Sheet

Arizona Public Service Company

$100,000,000

5.50% Notes due 2035

$600,000,000

6.25% Notes due 2056

August 10, 2026

Issuer:

Arizona

Public Service Company

Expected

Ratings (Moody’s / S&P / Fitch):

(__) / __ (__) / __ (__)

Note: A securities rating is not a recommendation to buy, sell or hold securities and may be subject to revision or withdrawal

at any time.

Trade

Date:

August 10,

2026

Settlement

Date:

August 13,

2026 (T+3)

Security:

5.50%

Notes due 2035 (the “New 2035 Notes”) which will be part of the same series of debt securities issued on August 22,

2005 by the Issuer in the amount of $250,000,000 (the “Initial 2035 Notes”)

6.25%

Notes due 2056

Principal

Amount:

$100,000,000

$600,000,000

Interest

Payment Dates:

March 1

and September 1, commencing September 1, 2026

February 15

and August 15, commencing February 15, 2027

Maturity

Date:

September 1,

2035

August 15,

2056

Interest

Rate:

5.50%

6.25%

Benchmark

Treasury:

4.375%

due May 15, 2036

4.750%

due February 15, 2056

Benchmark

Treasury Price / Yield:

97-15+

/ 4.698%

92-17

/ 5.251%

Spread

to Benchmark Treasury:

+85

basis points

+107

basis points

Re-Offer

Yield:

5.548%

6.321%

Authorized

Denominations:

Minimum

denomination of $1,000 and any integral multiple of $1,000 in excess thereof

Minimum

denomination of $2,000 and any integral multiple of $1,000 in excess thereof

Public

Offering Price:

99.659%,

plus accrued interest from and including March 1, 2026 to but excluding the Settlement Date (such accrued interest totaling

$2,475,000)

99.050%

A-1

Optional

Redemption:

Make-whole

call at any time at Adjusted Treasury Rate (as defined in the Preliminary Prospectus Supplement dated August 10, 2026) plus

15 basis points

Make-whole

call at any time prior to February 15, 2056 at Treasury Rate (as defined in the Preliminary Prospectus Supplement dated August 10,

2026) plus 20 basis points and, thereafter, at par

Qualified

Reopening:

The

offering of the New 2035 Notes is expected to qualify as a “qualified reopening” of the Initial 2035 Notes under U.S.

Treasury regulations; see “Certain Material United States Federal Income Tax Consequences—Qualified Reopening of Reopened

2035 Notes” in the Preliminary Prospectus Supplement dated August 10, 2026

N/A

CUSIP/ISIN:

040555

CH5 / US040555CH53

040555

DL5 / US040555DL56

Joint

Book-Running Managers:

Barclays

Capital Inc.

BMO Capital Markets Corp.

Citigroup Global Markets Inc.

Morgan Stanley & Co. LLC

PNC Capital Markets LLC

U.S. Bancorp Investments, Inc.

Co-Manager:

Academy

Securities, Inc.

Arizona Public

Service Company has filed a registration statement (including a prospectus, as supplemented) with the Securities and Exchange Commission

(“SEC”) for the offering to which this communication relates. Before you invest, you should read the prospectus (as supplemented)

in that registration statement and other documents Arizona Public Service Company has filed with the SEC for more complete information

about Arizona Public Service Company and this offering. You may get these documents for free by visiting EDGAR on the SEC website at

www.sec.gov. Alternatively, Arizona Public Service Company, any underwriter or any dealer participating in the offering will arrange

to send you the prospectus if you request it by calling Barclays Capital Inc. toll-free at (888) 603-5847, BMO Capital

Markets Corp. toll-free at (888) 200-0266, Citigroup Global Markets Inc. toll-free at (800) 831-9146, Morgan Stanley & Co. LLC

toll free at (866) 718-1649, PNC Capital Markets LLC toll-free at (855) 881-0697 or U.S. Bancorp Investments, Inc. toll free at

(877) 558-2607.

A-2

Any disclaimers or other

notices that may appear below are not applicable to this communication and should be disregarded. Such disclaimers were automatically

generated as a result of this communication being sent via email or another communication system.

A-3

EX-4.2 — EXHIBIT 4.2

EX-4.2

Filename: tm2622461d5_ex4-2.htm · Sequence: 3

Exhibit 4.2

ARIZONA PUBLIC SERVICE COMPANY

THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.

As Trustee under Arizona Public Service Company’s

Indenture dated as of January 15, 1998

Thirty-Fourth Supplemental Indenture

Dated as of August 13, 2026

6.25% Notes due 2056

This THIRTY-FOURTH SUPPLEMENTAL

INDENTURE, dated as of August 13, 2026, is between Arizona Public Service Company, a corporation duly organized and existing under

the laws of the State of Arizona (herein called the “Company”), having its principal office at 400 North Fifth Street, Phoenix,

Arizona 85004, and The Bank of New York Mellon Trust Company, N.A., successor to JPMorgan Chase Bank, N.A. (formerly known as The Chase

Manhattan Bank), a national banking association, as Trustee (herein called the “Trustee”) under the Indenture dated as of

January 15, 1998 between the Company and the Trustee (the “Indenture”).

RECITALS OF THE COMPANY

The Company has executed

and delivered the Indenture to the Trustee to provide for the issuance from time to time of its unsecured debentures, notes or other

evidences of indebtedness (the “Securities”), said Securities to be issued in one or more series as provided in the Indenture.

Section 901(5) of

the Indenture provides that, without the consent of any Holders, the Company, when authorized by a Board Resolution, and the Trustee

may enter into one or more indentures supplemental to the Indenture for the purpose of adding to, changing or eliminating any of the

provisions of the Indenture in respect of one or more series of Securities, provided that any such addition, change or elimination shall

neither (i) apply to any Security of any series created prior to the execution of such supplemental indenture and entitled to the

benefit of such provision nor (ii) modify the rights of the Holder of any such Security with respect to such provision.

Section 901(7) of

the Indenture provides that, without the consent of any Holders, the Company, when authorized by a Board Resolution, and the Trustee

may enter into one or more indentures supplemental to the Indenture for the purpose of establishing the form or terms of Securities of

any series.

Pursuant to the terms of

the Indenture, the Company desires to provide for the establishment of a new series of its Securities to be known as its 6.25% Notes

due 2056 (herein called the “Notes”), the forms and substance of such Notes and the terms, provisions, and conditions thereof

to be set forth as provided in the Indenture and this Thirty-Fourth Supplemental Indenture.

All things necessary to make

this Thirty-Fourth Supplemental Indenture a valid agreement of the Company, and to make the Notes described herein, when executed by

the Company and authenticated and delivered by the Trustee, the valid obligations of the Company, have been done.

NOW, THEREFORE, THIS THIRTY-FOURTH

SUPPLEMENTAL INDENTURE WITNESSETH:

For and in consideration

of the premises and the purchase of the Notes by the Holders thereof, and for the purpose of setting forth, as provided in the Indenture,

the form and substance of each of the Notes and the terms, provisions, and conditions thereof, it is mutually agreed, for the equal and

proportionate benefit of all Holders of the Notes, as applicable, as follows:

ARTICLE One

GENERAL TERMS AND CONDITIONS OF THE NOTES

SECTION 101.        Authentication

and Delivery. There shall be and is hereby authorized a series of Securities designated the “6.25% Notes due 2056” initially

limited in aggregate principal amount to $600,000,000, which amount shall be as set forth in a Company Order for the authentication and

delivery of Notes. The Notes shall mature and the principal shall be due and payable together with all accrued and unpaid interest thereon

on August 15, 2056, and the Notes shall be issued in the form of registered Securities without coupons.

The foregoing principal amount

of the Notes may be increased from time to time as permitted by Section 301 of the Indenture. All Notes need not be issued at the

same time and such series may be reopened at any time, without notice to, or the consent of, the then existing Holders, for issuance

of additional Notes. Any such additional Notes will be equal in rank and have the same respective maturity, payment terms, redemption

features, and other terms as the Notes initially issued, except for the issue date, public offering price, payment of interest accruing

prior to the issue date, and first payment of interest following the issue date of the additional Notes, but the Company will not issue

additional Notes unless the additional Notes are fungible with the previously issued Notes for U.S. federal income tax purposes or are

issued with a separate CUSIP number.

SECTION 102.        Global

Security. The Notes shall be issued in certificated form, except that the Notes shall be issued initially as a Global Security to

and registered in the name of Cede & Co., as nominee of The Depository Trust Company, as Depositary therefor. Any Notes to be

issued or transferred to, or to be held by, Cede & Co. (or any successor thereof) for such purpose shall bear the depositary

legend in substantially the form set forth at the top of the form of Note in Section 301 hereof (in lieu of that set forth in Section 204

of the Indenture), unless otherwise agreed by the Company, such agreement to be confirmed in writing to the Trustee. Each such Global

Security may be exchanged in whole or in part for Notes registered, and any transfer of such Global Security in whole or in part may

be registered, in the name(s) of Persons other than such Depositary or a nominee thereof only under the circumstances set forth

in clause (2) of the last paragraph of Section 305 of the Indenture, or such other circumstances in addition to or in lieu

of those set forth in clause (2) of the last paragraph of Section 305 of the Indenture as to which the Company shall agree,

such agreement to be confirmed in writing to the Trustee. Upon the occurrence of any such event, the Notes will be issued in such names

as the Depositary shall instruct the Trustee.

SECTION 103.        Place

of Payment and Place for Registration of Transfers and Exchange. Principal of, and premium, if any, and interest on, the Notes will

be payable, the transfer of Notes will be registrable and the Notes will be exchangeable for Notes bearing identical terms and provisions,

at the office or agency of the Company in the City of Pittsburgh, State of Pennsylvania; provided, however, that payment

of interest may be made at the option of the Company by wire transfer to any Holder or by deposit to the account of the Holder of any

such Notes if such account is maintained with the Trustee, in each case according to the written instructions given by such Holder on

or prior to the applicable record date to the Trustee, which written instructions shall remain in effect until revised by such Holder

by an instrument in writing delivered to the Trustee.

SECTION 104.        Payment

of Interest. The Notes will bear interest at the rate of 6.25% per annum from August 13, 2026 or from the most recent Interest

Payment Date (as hereinafter defined) to which interest has been paid or duly provided for until the principal thereof is paid or made

available for payment, payable semi-annually in arrears on February 15 and August 15 of each year (each, an “Interest

Payment Date”), commencing on February 15, 2027, to the person in whose name such Note or any Predecessor Security is registered

at 5:00 p.m., New York City time, on the Regular Record Date for such interest, which shall be (i) the Business Day immediately

preceding the relevant Interest Payment Date so long as all of the Notes remain in book-entry only form or (ii) the fifteenth calendar

day immediately preceding the relevant Interest Payment Date (whether or not a Business Day) if any of the Notes do not remain in book-entry

only form. Any such interest installment not punctually paid or duly provided for shall forthwith cease to be payable to the Holders

on such Regular Record Date, and may be paid to the Person in whose name such Note (or one or more Predecessor Securities) is registered

at the close of business on a Special Record Date to be fixed by the Trustee for the payment of such Defaulted Interest, notice whereof

shall be given to the Holders of the Notes not less than 10 days prior to such Special Record Date, or may be paid at any time in any

other lawful manner not inconsistent with the requirements of any securities exchange on which the Notes may be listed, and upon such

notice as may be required by such exchange, all as more fully described in the Indenture.

The amount of interest payable

for any period will be computed on the basis of a 360-day year of twelve 30-day months. Interest will accrue from August 13, 2026

or from the most recent Interest Payment Date to which interest has been paid or duly provided for to, but not including, the relevant

payment date. In the event that any Interest Payment Date (including the date of maturity) or Redemption Date is not a Business Day,

then any payment due on such date may be made on the next succeeding Business Day (without any interest or other payment in respect of

any such delay), in each case with the same force and effect as if made on such date. A “Business Day” shall mean any day

except a Saturday, a Sunday or a legal holiday in The City of New York on which banking institutions are authorized or required by law,

regulation or executive order to close.

SECTION 105.        Redemption

of the Notes. Prior to February 15, 2056 (the “Par Call Date”), the Company may redeem the Notes at its option,

in whole or in part, at any time and from time to time, at a Redemption Price (expressed as a percentage of principal amount and rounded

to three decimal places) equal to the greater of:

(1)                (a) the

sum of the present values of the remaining scheduled payments of principal and interest on the Notes to be redeemed discounted to the

Redemption Date (assuming the Notes to be redeemed matured on the Par Call Date) on a semi-annual basis (assuming a 360-day year consisting

of twelve 30-day months) at the Treasury Rate (as defined below), plus 20 basis points, less (b) interest accrued to the Redemption

Date; and

(2)                100%

of the principal amount of the Notes to be redeemed;

plus, in either case, accrued and unpaid interest,

if any, thereon to, but not including, the Redemption Date.

On or after the Par Call

Date, the Company may redeem the Notes at its option, in whole or in part, at any time and from time to time, at a Redemption Price equal

to 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest, if any, thereon to, but not including,

the Redemption Date.

The Company’s actions

and determinations in determining the Redemption Price shall be conclusive and binding for all purposes, absent manifest error.

Notice of any redemption

will be mailed or electronically delivered (or otherwise transmitted in accordance with the Depositary’s procedures) at least 10

days but not more than 60 days before the Redemption Date to the Trustee and each holder of Notes to be redeemed.

If less than all of the Notes

are to be redeemed and (i) the Notes are in global form, the interests in the Notes to be redeemed shall be selected for redemption

by The Depository Trust Company (“DTC”) in accordance with DTC’s standard procedures therefor, or (ii) the Notes

are in definitive form, the Notes to be redeemed shall be selected by lot. No Notes of a principal amount of $2,000 or less will be redeemed

in part. If any Note is to be redeemed in part only, the notice of redemption that relates to the Note will state the portion of the

principal amount of the Note to be redeemed. A new Note in a principal amount equal to the unredeemed portion of the Note will be issued

in the name of the holder of the Note upon surrender for cancellation of the original Note. For so long as the Notes are held by DTC

(or another Depositary), the redemption of the Notes shall be done in accordance with the policies and procedures of the Depositary.

Unless the Company defaults

in payment of the Redemption Price, on and after the Redemption Date, interest will cease to accrue on the Notes or portions thereof

called for redemption.

Notwithstanding the foregoing,

installments of interest on Notes that are due and payable on Interest Payment Dates falling on or prior to the Redemption Date will

be payable on the Interest Payment Date to the registered holders as of the close of business on the relevant record date according to

the Notes and the Indenture. The Trustee shall have no obligation to calculate the Redemption Price.

Notwithstanding Section 1104

of the Indenture, any notice of redemption given pursuant to said Section with respect to the foregoing redemption need not set

forth the Redemption Price but only the manner of calculation thereof.

For purposes of this Section 105,

“Treasury Rate” means, with respect to any Redemption Date, the yield determined by the Company in accordance with

the following two paragraphs.

The Treasury Rate shall be

determined by the Company after 4:15 p.m., New York City time (or after such time as yields on U.S. government securities are posted

daily by the Board of Governors of the Federal Reserve System), on the third business day preceding the Redemption Date based upon the

yield or yields for the most recent day that appear after such time on such day in the most recent statistical release published by the

Board of Governors of the Federal Reserve System designated as “Selected Interest Rates (Daily) - H.15” (or any successor

designation or publication) (“H.15”) under the caption “U.S. government securities–Treasury constant maturities–Nominal”

(or any successor caption or heading) (“H.15 TCM”). In determining the Treasury Rate, the Company shall select, as applicable:

(1) the yield for the Treasury constant maturity on H.15 exactly equal to the period from the Redemption Date to the Par Call Date

(the “Remaining Life”); or (2) if there is no such Treasury constant maturity on H.15 exactly equal to the Remaining

Life, the two yields—one yield corresponding to the Treasury constant maturity on H.15 immediately shorter than and one yield corresponding

to the Treasury constant maturity on H.15 immediately longer than the Remaining Life—and shall interpolate to the Par Call Date

on a straight-line basis (using the actual number of days) using such yields and rounding the result to three decimal places; or (3) if

there is no such Treasury constant maturity on H.15 shorter than or longer than the Remaining Life, the yield for the single Treasury

constant maturity on H.15 closest to the Remaining Life. For purposes of this paragraph, the applicable Treasury constant maturity or

maturities on H.15 shall be deemed to have a maturity date equal to the relevant number of months or years, as applicable, of such Treasury

constant maturity from the Redemption Date.

If on the third business

day preceding the Redemption Date H.15 TCM is no longer published, the Company shall calculate the Treasury Rate based on the rate per

annum equal to the semi-annual equivalent yield to maturity at 11:00 a.m., New York City time, on the second business day preceding such

Redemption Date of the United States Treasury security maturing on, or with a maturity that is closest to, the Par Call Date, as applicable.

If there is no United States Treasury security maturing on the Par Call Date but there are two or more United States Treasury securities

with a maturity date equally distant from the Par Call Date, one with a maturity date preceding the Par Call Date and one with a maturity

date following the Par Call Date, the Company shall select the United States Treasury security with a maturity date preceding the Par

Call Date. If there are two or more United States Treasury securities maturing on the Par Call Date or two or more United States Treasury

securities meeting the criteria of the preceding sentence, the Company shall select from among these two or more United States Treasury

securities the United States Treasury security that is trading closest to par based upon the average of the bid and asked prices for

such United States Treasury securities at 11:00 a.m., New York City time. In determining the Treasury Rate in accordance with the terms

of this paragraph, the semi-annual yield to maturity of the applicable United States Treasury security shall be based upon the average

of the bid and asked prices (expressed as a percentage of principal amount) at 11:00 a.m., New York City time, of such United States

Treasury security, and rounded to three decimal places.

If a Tax Credit Event (as

defined below) occurs, the Company may redeem the Notes, at its option, in whole but not in part, at a Redemption Price equal to 101%

of the principal amount of the Notes, plus accrued and unpaid interest, if any, thereon to, but not including, the Redemption Date. A

notice of redemption of the Notes upon the occurrence of a Tax Credit Event (i) may only be sent by the later of (a) the end

of the calendar year in which the Notes were issued and (b) six months from the date of issuance of the Notes and (ii) shall

be accompanied by an Officers’ Certificate of the Company stating that a Tax Credit Event has occurred.

The consummation of a redemption

upon a Tax Credit Event may be subject to the Trustee’s receipt of the required redemption moneys on or before the Redemption Date

(and in such case no such redemption shall occur unless such moneys have been received by the Trustee on or before such date).

A “Tax Credit Event”

occurs with respect to the Notes if, in the Company’s reasonable determination, there exists a material risk, due to the Notes

(considered together with other debt) having been issued, as part of an original issuance, to one or more “specified foreign entities”,

as defined in Section 7701(a)(51)(B) of the Internal Revenue Code of 1986, as amended (the “Code”), that the Company

or any of its affiliates would be unable to utilize or otherwise ineligible to claim any tax credits otherwise allowed under Section 38

of the Code.

SECTION 106.        Defeasance

of the Notes. The Notes shall be defeasible pursuant to Section 1302 or 1303 of the Indenture.

SECTION 107.        Minimum

Denominations. The Notes shall be issuable in minimum denominations of $2,000 and any integral multiple of $1,000 in excess thereof.

SECTION 108.        Election

to Redeem; Notice to Trustee. Solely for purposes of the Notes, Section 1102 of the Indenture shall be amended by replacing

“60 days” with “15 days”.

SECTION 109.        Notice

of Redemption. Solely for purposes of the Notes, Section 1104 of the Indenture shall be amended by replacing “30”

with “10”.

SECTION 110.        Execution

and Authentication of the Notes. Solely for purposes of the Notes, Section 303 of the Indenture shall be amended by adding “,

electronic” after “manual” in the first and second paragraphs, and by adding “or electronic” after “manual”

in the last paragraph thereof.

ARTICLE Two

ADDITIONAL COVENANT

SECTION 201.        Negative

Lien Covenant. (a)        So long as any of the Notes are Outstanding, the Company will not issue, assume,

guarantee or permit to exist any Debt secured by any mortgage, security interest, pledge or lien (herein referred to as a “Mortgage”)

of or upon any Operating Property of the Company, whether owned at the date of this Thirty-Fourth Supplemental Indenture or hereafter

acquired, without effectively securing the Notes (together with, if the Company shall so determine, any other indebtedness or obligations

of the Company ranking senior to, or equally with, the Notes) equally and ratably with such Debt (but only so long as such Debt is so

secured); provided, however, that the foregoing restriction shall not apply to Debt secured by any of the following:

(1) Mortgages on any property existing at

the time of acquisition thereof (which Mortgages may also extend to subsequent repairs, alterations

and improvements to that property);

(2) Mortgages on property of a corporation

existing at the time such corporation is merged into or consolidated with the Company or

at the time of a sale, lease or other disposition of the properties of such corporation or

a division thereof as an entirety or substantially as an entirety to the Company;

(3) Mortgages on property to secure all or

part of the cost of acquiring, constructing, developing or substantially repairing, altering

or improving such property or to secure indebtedness incurred to provide funds for any such

purpose or for reimbursement of funds previously expended for any such purpose, provided

such Mortgages are created or assumed contemporaneously with, or within eighteen (18) months

after, such acquisition or completion of construction, development or substantial repair,

alteration or improvement;

(4) Mortgages in favor of the United States

of America or any State thereof, or any department, agency, instrumentality or political

subdivision of the United States of America or any State thereof, or for the benefit of holders

of securities issued by any such entity (or providers of credit enhancement with respect

to those securities), to secure any Debt (including the Company’s obligations with

respect to industrial development, pollution control or similar revenue bonds) incurred for

the purpose of financing or refinancing all or any part of the purchase price or the cost

of constructing, developing or substantially repairing, altering or improving the property

of the Company;

(5) Mortgages to compensate the Trustee as

provided in the Indenture; or

(6) any extension, renewal or replacement

(or successive extensions, renewals or replacements), in whole or in part, of any Mortgage

referred to in the foregoing clauses (1) to (5), inclusive; provided, however,

that the principal amount of Debt secured thereby and not otherwise authorized by said clauses

(1) to (5), inclusive, shall not exceed the principal amount of Debt, plus any premium

or fee payable in connection with any such extension, renewal or replacement, so secured

at the time of such extension, renewal or replacement.

(b)                Notwithstanding

the provisions of Section 201(a), the Company may issue, assume or guarantee or permit to exist Debt, secured by Mortgages that

would otherwise be subject to the restrictions set forth above in connection with the Company’s sale and leaseback transactions

relating to Unit 2 of the Palo Verde Nuclear Generating Station (the “Unit 2 Sale and Leaseback Transactions”), including

but not limited to Mortgages on the leased interests in Unit 2 of the Palo Verde Nuclear Generating Station and related rights if the

Company reacquires ownership in any of those interests or acquires any of the equity or owner participants’ interests in the trusts

that hold title to such leased interests, whether or not it also directly assumes the Sale Leaseback Obligation Bonds, and Mortgages

on the Company’s interests in the trusts that hold title to such leased interests and related rights in the event that the Company

acquires any of the equity or owner participants’ interests in such trusts pursuant to a “special transfer” under the

Unit 2 Sale and Leaseback Transactions. In addition, the Company may issue, assume or guarantee or permit to exist Debt that is secured

by Mortgages that would otherwise be subject to the restrictions set forth above up to an aggregate principal amount that, together with

the principal amount of all other Debt of the Company secured by such Mortgages, does not at the time exceed ten percent (10%) of Tangible

Assets.

purposes of this Section 201, the following terms shall have the following meanings:

“Debt” means

any outstanding debt of the Company for money borrowed evidenced by notes, debentures, bonds or other securities, or guarantees of any

thereof.

“Operating Property”

means (i) any interest in real property owned by the Company and (ii) any asset owned by the Company that is depreciable in

accordance with generally accepted accounting principles, excluding in any case any interest of the Company as lessee under any lease.

“Sale Leaseback Obligation

Bonds” means any bonds issued in connection with the Unit 2 Sale and Leaseback Transactions and any refinancing or refunding of

such obligations.

“Tangible Assets”

means the amount shown as total assets on the most recent balance sheet of the Company, less: (i) intangible assets, including,

but without limitation, goodwill, trademarks, trade names and patents and (ii) appropriate adjustments, if any, on account of minority

interests; provided, however, that if, subsequent to the date of the most recent balance sheet of the Company, the

Company acquires any property, whether by acquisition (including by way of capital lease) from a third party, through merger or consolidation,

through construction, development or substantial repair, alteration or improvement of property, or by any other means, and such property

is or becomes subject to any Mortgage securing Debt, the Company may prepare a pro forma balance sheet to include the value of such property

in any calculation of Tangible Assets hereunder. Subject to the foregoing, Tangible Assets shall be determined in accordance with generally

accepted accounting principles and practices applicable to the type of business in which the Company is engaged and that are approved

by the independent accountants regularly retained by the Company, and may be determined as of a date not more than 60 days prior to the

happening of the event for which such determination is being made.

ARTICLE Three

FORM OF

NOTES

SECTION 301.        Form of

Notes. The Notes and the Trustee’s certificate of authentication thereon shall be substantially in the following forms:

UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED

REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO ARIZONA PUBLIC SERVICE COMPANY OR ITS

AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO.

OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH

OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE

BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

ARIZONA PUBLIC SERVICE COMPANY

6.25% Note due 2056

No.

CUSIP

No.

040555

DL5

Arizona Public Service Company,

a corporation duly organized and existing under the laws of the State of Arizona (the “Company”, which term includes any

successor Person under the Indenture hereinafter referred to), for value received, hereby promises to pay to Cede & Co., or

registered assigns, the principal sum of ____________ Dollars ($____________) on August 15, 2056, and to pay interest thereon and

on any overdue interest from August 13, 2026 or from the most recent Interest Payment Date to which interest has been paid or duly

provided for, semi-annually in arrears on February 15 and August 15 of each year, commencing February 15, 2027, at the

rate of 6.25% per annum, until the principal hereof is paid or made available for payment. The amount of interest payable for any period

will be computed on the basis of a 360-day year of twelve 30-day months.

The interest so payable,

and punctually paid or duly provided for, on any Interest Payment Date will, as provided in such Indenture, be paid to the Person in

whose name this Security (or one or more Predecessor Securities) is registered at 5:00 p.m., New York City time, on the Regular Record

Date for such interest, which shall be (i) the Business Day immediately preceding the relevant Interest Payment Date so long as

all of the Securities of this series remain in book-entry only form or (ii) the fifteenth calendar day immediately preceding the

relevant Interest Payment Date (whether or not a Business Day) if any of the Securities of this series do not remain in book-entry only

form. Any such interest not so punctually paid or duly provided for will forthwith cease to be payable to the Holder on such Regular

Record Date and may either be paid to the Person in whose name this Security (or one or more Predecessor Securities) is registered at

the close of business on a Special Record Date for the payment of such Defaulted Interest to be fixed by the Trustee, notice whereof

shall be given to Holders of Securities of this series not less than 10 days prior to such Special Record Date, or be paid at any time

in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Securities of this series may

be listed, and upon such notice as may be required by such exchange, all as more fully provided in the Indenture.

Payment of the principal

of (and premium, if any) and any interest on this Security will be made at the office or agency of the Company maintained for that purpose

through the corporate trust office of the Trustee, in such coin or currency of the United States of America as at the time of payment

is legal tender for payment of public and private debts; provided, however, that payment of interest may be made at the

option of the Company by wire transfer to any Holder or by deposit to the account of the Holder of any such Securities if such account

is maintained with the Trustee, in each case according to the written instructions given by such Holder on or prior to the applicable

record date to the Trustee, which written instructions shall remain in effect until revised by such Holder by an instrument in writing

delivered to the Trustee.

Reference is hereby made

to the further provisions of this Security set forth following the Company’s signature hereto, which further provisions shall for

all purposes have the same effect as if set forth at this place.

Unless the certificate of

authentication hereon has been executed by the Trustee referred to following the Company’s signature hereto by manual or electronic

signature, this Security shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

IN WITNESS WHEREOF, the Company has caused this

instrument to be duly executed under its corporate seal.

ARIZONA PUBLIC SERVICE COMPANY

Attest:

This Security is one of a

duly authorized issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more

series under an Indenture, dated as of January 15, 1998 (such instrument as originally executed and delivered and as supplemented

or amended from time to time, the “Indenture”), between the Company and The Bank of New York Mellon Trust Company, N.A.,

successor to JPMorgan Chase Bank, N.A. (formerly known as The Chase Manhattan Bank), as Trustee (the “Trustee,” which term

includes any successor trustee under the Indenture), and reference is hereby made to the Indenture for a description of the respective

rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the Holders of the Securities and of

the terms upon which the Securities are, and are to be, authenticated and delivered. This Security is one of the series designated on

the face hereof.

Prior to February 15,

2056 (the “Par Call Date”), the Company may redeem the Securities of this series at its option, in whole or in part, at any

time and from time to time, at a Redemption Price (expressed as a percentage of principal amount and rounded to three decimal places)

equal to the greater of:

(1)                (a) the

sum of the present values of the remaining scheduled payments of principal and interest on the Securities of this series to be redeemed

discounted to the Redemption Date (assuming the Securities of this series to be redeemed matured on the Par Call Date) on a semi-annual

basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate (as defined below), plus 20 basis points, less

(b) interest accrued to the Redemption Date; and

(2)               100% of the principal

amount of the Securities of this series to be redeemed;

plus, in either case, accrued

and unpaid interest, if any, thereon to, but not including, the Redemption Date.

On or after the Par Call

Date, the Company may redeem the Securities of this series at its option, in whole or in part, at any time and from time to time, at

a Redemption Price equal to 100% of the principal amount of the Securities of this series to be redeemed, plus accrued and unpaid interest,

if any, thereon to, but not including, the Redemption Date. The Company’s actions and determinations in determining the Redemption

Price shall be conclusive and binding for all purposes, absent manifest error.

Notice of any redemption

will be mailed or electronically delivered (or otherwise transmitted in accordance with the Depositary’s procedures) at least 10

days but not more than 60 days before the Redemption Date to the Trustee and each holder of Securities of this series to be redeemed.

If less than all of the Securities

of this series are to be redeemed and (i) the Securities of this series are in global form, the interests in the Securities of this

series to be redeemed shall be selected for redemption by The Depository Trust Company (“DTC”) in accordance with DTC’s

standard procedures therefor, or (ii) the Securities of this series are in definitive form, the Securities of this series to be

redeemed shall be selected by lot. No Securities of this series of a principal amount of $2,000 or less will be redeemed in part. If

any Security of this series is to be redeemed in part only, the notice of redemption that relates to the Security of this series will

state the portion of the principal amount of the Security of this series to be redeemed. A new Security of this series in a principal

amount equal to the unredeemed portion of the Security of this series will be issued in the name of the holder of the Security of this

series upon surrender for cancellation of the original Security of this series. For so long as the Securities of this series are held

by DTC (or another Depositary), the redemption of the Securities of this series shall be done in accordance with the policies and procedures

of the Depositary.

Unless the Company defaults

in payment of the Redemption Price, on and after the Redemption Date, interest will cease to accrue on the Securities of this series

or portions thereof called for redemption.

Notwithstanding the foregoing,

installments of interest on Securities of this series that are due and payable on Interest Payment Dates falling on or prior to the Redemption

Date will be payable on the Interest Payment Date to the registered holders as of the close of business on the relevant record date according

to the Securities of this series and the Indenture. The Trustee shall have no obligation to calculate the Redemption Price.

Notwithstanding Section 1104

of the Indenture, any notice of redemption given pursuant to said Section with respect to the foregoing redemption need not set

forth the Redemption Price but only the manner of calculation thereof.

As used herein:

“Treasury Rate”

means, with respect to any Redemption Date, the yield determined by the Company in accordance with the following two paragraphs.