Form 8-K

8-K — Trinseo PLC

Accession: 0001104659-26-053165

Filed: 2026-04-30

Period: 2026-04-30

CIK: 0001519061

SIC: 2821 (PLASTICS, MATERIALS, SYNTH RESINS & NONVULCAN ELASTOMERS)

Item: Entry into a Material Definitive Agreement

Item: Regulation FD Disclosure

Item: Financial Statements and Exhibits

Documents

8-K — tm2613282d1_8k.htm (Primary)

XML — IDEA: XBRL DOCUMENT (R1.htm)

8-K — FORM 8-K

8-K (Primary)

Filename: tm2613282d1_8k.htm · Sequence: 1

false

0001519061

00-0000000

0001519061

2026-04-30

iso4217:USD

xbrli:shares

iso4217:USD

xbrli:shares

UNITED STATES

SECURITIES

AND EXCHANGE COMMISSION

Washington,

D.C. 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):

April 30, 2026

Trinseo

PLC

(Exact name of registrant

as specified in its charter)

Ireland

001-36473

N/A

(State or other jurisdiction

of incorporation or organization)

(Commission

File Number)

(I.R.S. Employer

Identification Number)

440

East Swedesford Road, Suite 301,

Wayne,

Pennsylvania 19087

(Address of principal

executive offices, including zip code)

(610) 240-3200

(Telephone number, including

area code)

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 (see General

Instruction A.2. below):

¨ 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

Ordinary Shares, par value $0.01 per share

TSEOF

N/A*

Indicate by check mark whether the registrant

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

of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

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. ¨

* On March 23, 2026, the NYSE filed a Form 25 relating to the delisting

from the NYSE of our ordinary shares. The delisting became effective on March 30, 2026. The ordinary shares will continue to trade over

the counter under the symbol “TSEOF.”

EXPLANATORY NOTE

This Current Report is being filed to report extensions of the expiration

dates of certain waiver agreements (collectively, the “Existing Waivers”) previously disclosed under Item 1.01 of, and filed

as exhibits to, the Current Report on Form 8-K filed by Trinseo PLC (the “Company”) with the U.S. Securities and Exchange

Commission on March 19, 2026 (the “Prior 8-K”). As permitted by the terms of the applicable Existing Waiver, the Company received

confirmations from the applicable counterparties extending the expiration date of each Existing Waiver as described below. No new waiver

agreement was entered into in connection with such extensions.

ITEM 1.01 Entry into a Material Definitive Agreement.

Revolver Waiver.

As permitted by the waiver under the Company’s super-priority

revolving credit facility dated January 17, 2025, the counterparties confirmed the extension of such waiver’s expiration date until

May 13, 2026.

Senior Credit Facility Waiver.

As permitted by the waiver under the Company’s Credit Agreement

dated as of September 6, 2017, the counterparties confirmed the extension of such waiver’s expiration date until May 13, 2026.

Refinance Credit Facility Waiver.

As permitted by the waiver under the Company’s Credit Agreement

dated as of September 8, 2023, the counterparties confirmed the extension of such waiver’s expiration date until May 13, 2026.

Securitization Waiver.

As permitted by the waiver under the Credit and Security Agreement

dated as of July 18, 2024 governing the Company’s accounts receivable securitization facility, the counterparties confirmed the

extension of such waiver’s expiration date until May 14, 2026.

The foregoing descriptions of the Existing Waivers are qualified in

their entirety by reference to the full text of each Existing Waiver, copies of which were filed as exhibits to the Prior 8-K and are

incorporated herein by reference.

ITEM 7.01 Regulation FD Disclosure.

The information set forth in the Explanatory Note and under Item 1.01

of this Current Report on Form 8-K is incorporated by reference into this Item 7.01. The information under this Item 7.01 of this Current

Report on Form 8-K is being furnished and shall not be deemed “filed” for the purpose of Section 18 of the Securities Exchange

Act of 1934, as amended, or otherwise subject to the liabilities of that Section. The information under this Item 7.01 shall not be incorporated

by reference into any registration statement or other document pursuant to the Securities Act of 1933, as amended.

Cautionary Note on Forward Looking Statements

This Current Report may contain forward-looking statements including,

without limitation, statements concerning plans, objectives, goals, projections, forecasts, strategies, future events or performance,

and underlying assumptions and other statements, which are not statements of historical facts or guarantees or assurances of future performance.

Forward-looking statements may be identified by the use of words like “expect,” “anticipate,” “believe,”

“intend,” “forecast,” “outlook,” “will,” “may,” “might,” “see,”

“tend,” “assume,” “potential,” “likely,” “target,” “plan,” “contemplate,”

“seek,” “attempt,” “should,” “could,” “would” or expressions of similar meaning.

Forward-looking statements reflect management’s evaluation of information currently available and are based on the Company’s

current expectations and assumptions regarding its business, the economy, its current indebtedness, and other future conditions. Because

forward-looking statements relate to the future, they are subject to inherent uncertainties, risks and changes in circumstances that are

difficult to predict. Factors that might cause future results to differ from those expressed by the forward-looking statements include,

but are not limited to, outcome of discussions with our financial stakeholders regarding our capital structure; our ability to successfully

restructure our indebtedness through an in-court or out-of-court process; our ability to obtain necessary waivers, consents or amendments

from our lenders; our ability to successfully execute our overall business and transformation strategy; increased costs or disruption

in the supply of raw materials; deterioration of our credit profile limiting our access to commercial credit; compliance with laws and

regulations impacting our business; conditions in the global economy and capital markets; our current and future levels of indebtedness

and ability to service our debt; our ability to meet the covenants under our existing indebtedness; our ability to generate cash flows

from operations; our ability to successfully implement and complete proposed restructuring initiatives and to successfully generate cost

savings through such initiatives; and those discussed in our Annual Report on Form 10-K, under Part I, Item 1A — “Risk Factors”

and elsewhere in our other reports, filings and furnishings made with the U.S. Securities and Exchange Commission from time to time. As

a result of these or other factors, the Company’s actual results, performance or achievements may differ materially from those contemplated

by the forward-looking statements. Therefore, we caution you against relying on any of these forward-looking statements. The forward-looking

statements included in this Current Report are made only as of the date hereof. The Company undertakes no obligation to publicly update

or revise any forward-looking statement as a result of new information, future events or otherwise, except as otherwise required by law.

ITEM 9.01

Exhibits.

104

Cover Page Interactive Data File (formatted in Inline XBRL and contained in Exhibit 101)

SIGNATURE

Pursuant to the requirements of the Securities

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

TRINSEO PLC

By:

/s/ David Stasse

Name:

David Stasse

Title:

Executive Vice President and Chief Financial Officer

Date: April 30, 2026

XML — IDEA: XBRL DOCUMENT

XML

Filename: R1.htm · Sequence: 6

v3.26.1

Cover

Apr. 30, 2026

Cover [Abstract]

Document Type

8-K

Amendment Flag

false

Document Period End Date

Apr. 30, 2026

Entity File Number

001-36473

Entity Registrant Name

Trinseo

PLC

Entity Central Index Key

0001519061

Entity Tax Identification Number

00-0000000

Entity Incorporation, State or Country Code

Entity Address, Address Line One

440

East Swedesford Road

Entity Address, Address Line Two

Suite 301

Entity Address, City or Town

Wayne

Entity Address, State or Province

Entity Address, Postal Zip Code

19087

City Area Code

610

Local Phone Number

240-3200

Written Communications

false

Soliciting Material

false

Pre-commencement Tender Offer

false

Pre-commencement Issuer Tender Offer

false

Title of 12(b) Security

Ordinary Shares, par value $0.01 per share

Trading Symbol

TSEOF

Entity Emerging Growth Company

false

- Definition

Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

+ References

No definition available.

+ Details

Name:

dei_AmendmentFlag

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Area code of city

+ References

No definition available.

+ Details

Name:

dei_CityAreaCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Cover page.

+ References

No definition available.

+ Details

Name:

dei_CoverAbstract

Namespace Prefix:

dei_

Data Type:

xbrli:stringItemType

Balance Type:

Period Type:

duration

- Definition

For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

+ References

No definition available.

+ Details

Name:

dei_DocumentPeriodEndDate

Namespace Prefix:

dei_

Data Type:

xbrli:dateItemType

Balance Type:

Period Type:

duration

- Definition

The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

+ References

No definition available.

+ Details

Name:

dei_DocumentType

Namespace Prefix:

dei_

Data Type:

dei:submissionTypeItemType

Balance Type:

Period Type:

duration

- Definition

Address Line 1 such as Attn, Building Name, Street Name

+ References

No definition available.

+ Details

Name:

dei_EntityAddressAddressLine1

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Address Line 2 such as Street or Suite number

+ References

No definition available.

+ Details

Name:

dei_EntityAddressAddressLine2

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Name of the City or Town

+ References

No definition available.

+ Details

Name:

dei_EntityAddressCityOrTown

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Code for the postal or zip code

+ References

No definition available.

+ Details

Name:

dei_EntityAddressPostalZipCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Name of the state or province.

+ References

No definition available.

+ Details

Name:

dei_EntityAddressStateOrProvince

Namespace Prefix:

dei_

Data Type:

dei:stateOrProvinceItemType

Balance Type:

Period Type:

duration

- Definition

A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityCentralIndexKey

Namespace Prefix:

dei_

Data Type:

dei:centralIndexKeyItemType

Balance Type:

Period Type:

duration

- Definition

Indicate if registrant meets the emerging growth company criteria.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityEmergingGrowthCompany

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

+ References

No definition available.

+ Details

Name:

dei_EntityFileNumber

Namespace Prefix:

dei_

Data Type:

dei:fileNumberItemType

Balance Type:

Period Type:

duration

- Definition

Two-character EDGAR code representing the state or country of incorporation.

+ References

No definition available.

+ Details

Name:

dei_EntityIncorporationStateCountryCode

Namespace Prefix:

dei_

Data Type:

dei:edgarStateCountryItemType

Balance Type:

Period Type:

duration

- Definition

The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityRegistrantName

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityTaxIdentificationNumber

Namespace Prefix:

dei_

Data Type:

dei:employerIdItemType

Balance Type:

Period Type:

duration

- Definition

Local phone number for entity.

+ References

No definition available.

+ Details

Name:

dei_LocalPhoneNumber

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 13e

-Subsection 4c

+ Details

Name:

dei_PreCommencementIssuerTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14d

-Subsection 2b

+ Details

Name:

dei_PreCommencementTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Title of a 12(b) registered security.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b

+ Details

Name:

dei_Security12bTitle

Namespace Prefix:

dei_

Data Type:

dei:securityTitleItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14a

-Subsection 12

+ Details

Name:

dei_SolicitingMaterial

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Trading symbol of an instrument as listed on an exchange.

+ References

No definition available.

+ Details

Name:

dei_TradingSymbol

Namespace Prefix:

dei_

Data Type:

dei:tradingSymbolItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Securities Act

-Number 230

-Section 425

+ Details

Name:

dei_WrittenCommunications

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration