{"url_path":"/sec/tseof/10-k/2026/item-13","section_key":"item-13","section_title":"Item 13 Certain Relationships and Related Transactions, and Director Independence","topic":"sec","document":{"doc_type":"10-K/A","doc_date":"2026-04-27","source_url":"https://www.sec.gov/Archives/edgar/data/1519061/0001104659-26-049440-index.html","accession_number":"0001104659-26-049440","cik":"0001519061","ticker":"TSEOQ","issuer_name":"Trinseo PLC","edgar_url":"https://www.sec.gov/Archives/edgar/data/1519061/0001104659-26-049440-index.html","primary_entity_key":"0001519061","primary_entity_name":"Trinseo PLC"},"word_count":4196,"has_tables":true,"body_markdown":"Item 13. Certain Relationships and Related Transactions, and Director Independence\n\nCertain Relationships and Related Transactions\n\nOur audit committee charter requires that the audit committee review and approve all related party transactions. The Company also has a written Related Party Transactions Policy and requires its officers and directors to submit a related party questionnaire annually, and provide updates as needed. When related party transactions between us and our officers, directors and principal shareholders and their affiliates are approved by the audit committee, it does so with the understanding that the terms of such transaction are no less favorable to us than those that we could obtain from unaffiliated third parties.\n\nOur Conflict of Interest Policy is designed to help our directors, executive officers, and employees address situations that may involve a conflict of interest, which may include related party transactions. These include situations in which an individual’s personal interests are in conflict with the interests of the Company; situations in which an individual or family member receives personal benefits as a result of his or her position with the Company; and situations that may otherwise cast doubt on his or her ability to act objectively with or on behalf of the Company. The Company annually surveys our executive officers and directors regarding potential conflicts of interest. If such conflicts are reported or found, the Legal Department and/or our Chief Compliance Officer will seek to mitigate or eliminate such potential or actual conflicts of interest.\n\nBoard Independence\n\nOur Corporate Governance Guidelines provide that our Board shall consist of such number of directors who are independent as is required and determined in accordance with applicable laws and regulations and requirements of the NYSE. The Board evaluates any relationships of each director and nominee with Trinseo and makes an affirmative determination whether or not such director or nominee is independent. Under our Corporate Governance Guidelines, an “independent” director is one who meets the qualification requirements for being an independent director under applicable laws and the corporate governance listing standards of the NYSE. Our Board reviews any transactions and relationships between each director or any member of his or her immediate family and Trinseo. The purpose of this review is to determine whether there were any such relationships or transactions and, if so, whether they were inconsistent with a determination that the director was independent. The Company maintains a related party transactions policy and conflict of interest policy, as discussed above. As a result of its review, our Board has affirmatively determined that all of our current directors and nominees, except for our CEO and President, Frank Bozich, are independent under the governance and listing standards of the NYSE.\n\n33\n\n[Table of Contents](#TOC)\n\nItem **14.**Principal Accounting Fees and Services\n\nOur independent registered public accounting firm is PricewaterhouseCoopers LLP (“PwC”), Philadelphia, Pennsylvania, Auditor ID: 238.\n\n​\n\nAudit and Other Fees\n\nThe following table shows the fees for professional services rendered by PwC for the year ended December 31, 2025 (fiscal 2025) and the year ended December 31, 2024 (fiscal 2024):\n\n​\n\n​\n\n​\n\n​\n\n​\n\n​\n\n​\n\n**  ​ ​ ​**\n\n**2025**\n\n**  ​ ​ ​**\n\n**2024**\n\nAudit fees (1)\n\n​\n\n$\n\n5,902,000\n\n \n\n6,069,000\n\nAudit-related fees (2)\n\n​\n\n$\n\n15,000\n\n \n\n245,000\n\nTax fees (3)\n\n​\n\n$\n\n420,000\n\n \n\n417,000\n\nAll other fees (4)\n\n​\n\n$\n\n2,000\n\n \n\n2,000\n\nTotal fees\n\n​\n\n$\n\n6,339,000\n\n \n\n6,733,000\n\n(1)Consists of the audit of the Company’s financial statements and evaluation and reporting on the effectiveness of the Company’s internal controls over financial reporting, statutory audits, reviews of the Company’s quarterly financial statements, as well as services performed in conjunction with other SEC and regulatory filings. These fees include $342,000 and $336,000 paid to PricewaterhouseCoopers for the audit of all statutory accounts required by Irish law during fiscal 2025 and fiscal 2024, respectively.\n\n(2)Primarily consists of services related to financial due diligence, German energy audits, and various other agreed upon procedures. The decrease in fiscal 2025 vs. fiscal 2024 in audit-related fees is mainly due to financial due diligence services.\n\n(3)Consists of tax compliance, tax audit defense, as well as worldwide tax advisory and consulting services.\n\n(4)Consists of subscriptions to knowledge tools.\n\nPre-Approval Policies and Procedures\n\nThe Audit Committee pre-approves all audit services and all permitted non-audit services by PwC, including engagement fees and terms. Our policies prohibit the Company from engaging PwC to provide any services relating to bookkeeping or other services related to accounting records or financial statements, financial information system design and implementation, appraisal or valuation services, fairness opinions or contribution-in-kind reports, actuarial services, internal audit outsourcing, any management function, legal services or expert services not related to the audit, broker-dealer, investment adviser, or investment banking services or human resource consulting. In addition, we evaluate whether the Company’s use of PwC for permitted non-audit services is compatible with maintaining PwC’s independence. We concluded that PwC’s provision of non-audit services, all of which we approved in advance, was compatible with its independence.\n\n​\n\n34\n\n[Table of Contents](#TOC)\n\nPart IV\n\nItem **15.**Exhibits, Financial Statement Schedules\n\nThis Amendment to the Original Form 10-K is being filed solely to include the information required by Part III of Form 10-K.\n\nExcept as expressly set forth in this Amendment, the Company’s Original Form 10-K, filed with the SEC on March 13, 2026, remains unchanged and continues to speak as of the date of the original filing. This Amendment does not modify or update the financial statements, exhibits, or any other disclosures contained in the Original Form 10-K.\n\nPart IV (Item 15) of the Company’s Original Filing is hereby amended solely to add the following exhibits required to be filed in connection with this Amendment No. 1.\n\n​\n\n35\n\n[Table of Contents](#TOC)\n\nEXHIBIT INDEX\n\n​\n\n​\n\n**Exhibit No.**\n\n​\n\n**Description**\n\n3.1\n\n​\n\n[Memorandum and Articles of Association of Trinseo PLC, as amended (incorporated by reference to Exhibit 3.1 to the Current Report on Form 8-K, filed on June 17, 2022)](https://www.sec.gov/Archives/edgar/data/1519061/000155837022010104/tse-20220614xex3d1.htm)\n\n​\n\n​\n\n​\n\n4.1\n\n​\n\n[Indenture among Trinseo Luxco Finance SPV S.à r.l., Trinseo NA Finance SPV LLC, the guarantors named therein, The Bank of New York Mellon, as trustee, and Alter Domus (US) LLC, as collateral agent, dated as of January 17, 2025 (incorporated by reference to Exhibit 4.2 to the Current Report on Form 8-K filed January 21, 2025)exhibit:https://www.sec.gov/Archives/edgar/data/1519061/000110465917055520/a17-21320_1ex4d1.htm](https://www.sec.gov/Archives/edgar/data/1519061/000110465925004689/tm253651d1_ex4-2.htm)\n\n​\n\n​\n\n​\n\n4.2\n\n​\n\n[Form of Global Restricted Note due 2029 (incorporated by reference as Exhibit A to Exhibit 4.2 to the Current Report on Form 8-K filed January 21, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465925004689/tm253651d1_ex4-2.htm)\n\n​\n\n​\n\n​\n\n4.3\n\n​\n\n[Description of Securities (incorporated by reference to Exhibit 4.5 to the Annual Report on Form 10-K for the year ended December 31, 2024, filed on February 27, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000155837025001736/tse-20241231xex4d5.htm)\n\n​\n\n​\n\n​\n\n10.1\n\n​\n\n[Credit Agreement among Trinseo Materials Operating S.C.A., Trinseo Materials Finance, Inc. together with Trinseo Holdings S.à r.l., and Trinseo Materials S.à r.l., Deutsche Bank AG New York Branch, as administrative agent, collateral agent, L/C issuer and swing line lender, and the guarantors and lenders from time to time party thereto, dated as of September 6, 2017 (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K, filed September 7, 2017)](https://www.sec.gov/Archives/edgar/data/1519061/000110465917056163/a17-21441_1ex10d1.htm)\n\n​\n\n​\n\n​\n\n10.2\n\n​\n\n[Amendment to the Credit Agreement dated September 6, 2017 among Trinseo Materials Operating S.C.A., Trinseo Materials Finance, Inc., together with Trinseo Holding S.à r.l. and Trinseo Materials S.à r.l., Deutsche Bank AG New York Branch, as administrative agent, collateral agent, L/C issuer and swing line lender, and the guarantors and lenders party thereto from time to time, dated as of May 22, 2018 (incorporated by reference to Exhibit 10.2 to the Quarterly Report on Form 10-Q for the quarter ended June 30, 2018, filed on August 3, 2018)](https://www.sec.gov/Archives/edgar/data/1519061/000155837018006334/tse-20180630ex102303da1.htm)\n\n​\n\n​\n\n​\n\n10.3\n\n​\n\n[2021 Incremental Amendment to Credit Agreement dated September 6, 2017, among, inter alios, Trinseo Materials Operating S.C.A., Trinseo Materials Finance, Inc. and Deutsche Bank AG New York Bank, dated as of May 3, 2021 (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed May 5, 2021)](https://www.sec.gov/Archives/edgar/data/1519061/000110465921061765/tm2114878d2_ex10-1.htm)\n\n​\n\n​\n\n​\n\n10.4\n\n​\n\n[2021 Revolver Amendment to Credit Agreement dated September 6, 2017, among, inter alios, Trinseo Materials Operating S.C.A., Trinseo Materials Finance, Inc. and Deutsche Bank AG New York Bank, dated as of May 3, 2021 (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed May 5, 2021)](https://www.sec.gov/Archives/edgar/data/1519061/000110465921061765/tm2114878d2_ex10-2.htm)\n\n​\n\n​\n\n​\n\n10.5\n\n​\n\n[2023 SOFR Amendment to the Credit Agreement dated September 6, 2017 among Trinseo Materials Operating S.C.A., Trinseo Materials Finance, Inc., together with Trinseo Holding S.à r.l. and Trinseo Ireland Holdings Limited, Deutsche Bank AG New York Branch, as administrative agent, collateral agent, L/C issuer and swing line lender, and the guarantors and lenders party thereto from time to time, dated as of June 30, 2023 (incorporated by reference to Exhibit 10.2 to the Quarterly Report on Form 10-Q for the quarter ended June 30, 2023, filed on August 4, 2023)](https://www.sec.gov/Archives/edgar/data/1519061/000155837023013353/tse-20230630xex10d2.htm)\n\n​\n\n​\n\n​\n\n10.6\n\n​\n\n[2023 Incremental and Refinancing Amendment to the Credit Agreement dated September 6, 2017, among Trinseo Holding S.à r.l., Trinseo Ireland Holdings Limited, Trinseo Materials Operating S.C.A., Trinseo Materials Finance, Inc. the guarantors party thereto from time to time, the lenders party thereto from time to time and Deutsche Bank AG New York Branch, as administrative agent and collateral agent, dated as of September 8, 2023 (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed on September 8, 2023)](https://www.sec.gov/Archives/edgar/data/1519061/000110465923099167/tm2325668d1_ex10-2.htm)\n\n​\n\n​\n\n​\n\n10.7\n\n​\n\n[2024 LuxCo Merger Amendment to the Credit Agreement dated September 6, 2017, among Trinseo Holding S.à r.l., Trinseo Materials Finance, Inc., Trinseo LuxCo S.à r.l. Deutsche Bank AG New York Branch, as Administrative Agent, dated as of December 12, 2024 (incorporated by reference to Exhibit 10.3 to the Current Report on Form 8-K filed December 16, 2024)](https://www.sec.gov/Archives/edgar/data/1519061/000110465924129105/tm2431127d1_ex10-3.htm)\n\n​\n\n​\n\n​\n\n36\n\n[Table of Contents](#TOC)\n\n​\n\n**Exhibit No.**\n\n​\n\n**Description**\n\n10.8§\n\n​\n\n[2025 Incremental Amendment to the Credit Agreement dated September 6, 2017, by and among Trinseo Luxco S.à r.l., Trinseo Holding S.à r.l., Trinseo Materials Finance, Inc., Trinseo Luxco Finance SPV S.à r.l., and Deutsche Bank AG New York Branch, as administrative agent, collateral agent, L/C issuer and swing line lender, and the guarantors and lenders party thereto, dated as of January 17, 2025 (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed January 21, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465925004689/tm253651d1_ex10-2.htm)\n\n​\n\n​\n\n​\n\n10.9\n\n​\n\n[2026 Grace Period Amendment to the Credit Agreement dated September 6, 2017, by and among Trinseo Luxco S.à r.l., Trinseo Holding S.à r.l., Trinseo Materials Finance, Inc. and the lenders party thereto, dated as of February 16, 2026 (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed February 16, 2026)](https://www.sec.gov/Archives/edgar/data/1519061/000110465926015648/tse-20260216xex10d1.htm)\n\n​\n\n​\n\n​\n\n10.10\n\n​\n\n[Credit Agreement, dated as of September 8, 2023, among Trinseo Luxco SARL, Trinseo NA Finance LLC, Trinseo Luxco Finance SPV SARL, Trinseo NA Finance SPV LLC, the guarantors party thereto from time to time, the lenders party thereto from time to time and Alter Domus (US) LLC, as administrative agent and collateral agent (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed on September 8, 2023)](https://www.sec.gov/Archives/edgar/data/1519061/000110465923099167/tm2325668d1_ex10-1.htm)\n\n​\n\n​\n\n​\n\n10.11\n\n​\n\n[First Amendment to Credit Agreement, dated January 26, 2024, to the Credit Agreement dated as of September 8, 2023 among Trinseo Luxco SARL, Trinseo NA Finance LLC, Trinseo Luxco Finance SPV SARL, Trinseo NA Finance SPV LLC, the guarantors party thereto from time to time, the lenders party thereto from time to time and Alter Domus (US) LLC, as administrative agent and collateral agent (incorporated by reference to Exhibit 10.8 to the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, filed on February 23, 2024)](https://www.sec.gov/Archives/edgar/data/1519061/000155837024001604/tse-20231231xex10d8.htm)\n\n​\n\n​\n\n​\n\n10.12\n\n​\n\n[Second Amendment to Credit Agreement by and among Trinseo LuxCo S.à.r.l., Trinseo NA Finance LLC, Trinseo LuxCo Finance SPV S.à.r.l., Trinseo NA Finance SPV LLC, Trinseo PLC, and Alter Domus (US) LLC, as Administrative Agent, dated December 12, 2024 (incorporated by reference to Exhibit 10.4 to the Current Report on Form 8-K filed December 16, 2024)](https://www.sec.gov/Archives/edgar/data/1519061/000110465924129105/tm2431127d1_ex10-4.htm)\n\n​\n\n​\n\n​\n\n10.13§\n\n​\n\n[Third Amendment to Credit Agreement dated as of September 8, 2023, by and among Trinseo NA Finance LLC, Trinseo LuxCo Finance SPV S.à r.l., Trinseo NA Finance SPV LLC, Trinseo PLC, and Alter Domus (US) LLC, as administrative agent and collateral agent, dated January 17, 2025 (incorporated by reference to Exhibit 10.3 to the Current Report on Form 8-K filed January 21, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465925004689/tm253651d1_ex10-3.htm)\n\n​\n\n​\n\n​\n\n10.14§§\n\n​\n\n[Transaction Support Agreement, dated December 9, 2024, by and among the Company, and certain of their direct and indirect subsidiaries party thereto, and each of the Supporting Creditors named therein (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed December 11, 2024)](https://www.sec.gov/Archives/edgar/data/1519061/000110465924127417/tm2430477d2_ex10-1.htm)\n\n​\n\n​\n\n​\n\n10.15§§\n\n​\n\n[Deed of Release and Termination, dated July 18, 2024, entered into by and among Trinseo Europe GmbH, Trinseo Export GmbH, Trinseo Deutschland Anlagengesellschaft mbH, Trinseo Netherlands B.V., Altuglas LLC, Aristech Surfaces, LLC, Trinseo LLC, Trinseo U.S. Receivables Company SPV LLC, Styron Receivables Funding Designated Activity Company, Regency Assets Designated Activity Company, HSBC Bank plc, Trinseo Holding S.à r.l., TMF Administration Services Limited and the Law Debenture Trust Corporation plc (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed July 22, 2024)](https://www.sec.gov/Archives/edgar/data/1519061/000155837024009949/tse-20240718xex10d2.htm)\n\n​\n\n​\n\n​\n\n10.16§§\n\n​\n\n[Credit and Security Agreement, dated July 18, 2024, among Styron Receivables Funding Designated Activity Company, Trinseo Ireland Global IHB Limited, KKR Credit Advisors (US) LLC, GLAS USA LLC, GLAS Americas LLC, and the Lenders from time to time party thereto (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed July 22, 2024)](https://www.sec.gov/Archives/edgar/data/1519061/000155837024009949/tse-20240718xex10d1.htm)\n\n​\n\n​\n\n​\n\n10.17\n\n​\n\n[First Amendment, dated as of February 24, 2026, to the Credit and Security Agreement dated July 18, 2024, among Styron Receivables Funding Designated Activity Company, Trinseo Ireland Global IHB Limited, KKR Credit Advisors (US) LLC, GLAS USA LLC, GLAS Americas LLC, and the Lenders from time to time party thereto (incorporated by reference to Exhibit 10.17 to the Annual Report on Form 10-K for the year ended December 31, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465926027518/tse-20251231xex10d17.htm)\n\n​\n\n​\n\n​\n\n37\n\n[Table of Contents](#TOC)\n\n​\n\n**Exhibit No.**\n\n​\n\n**Description**\n\n10.18§\n\n​\n\n[Credit Agreement, by and among Trinseo Luxco S.à r.l., Trinseo Holding S.à r.l., Trinseo Materials Finance, Inc., Deutsche Bank AG New York Branch, as administrative agent and collateral agent, and the guarantors and lenders party thereto, dated as of January 17, 2025 (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed January 21, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465925004689/tm253651d1_ex10-1.htm)\n\n​\n\n​\n\n​\n\n10.19*\n\n​\n\n[Employment Agreement between Trinseo LLC and Frank A. Bozich, dated December 11, 2018 (incorporated herein by reference to Exhibit 10.1 to the Company’s Current Report on Form 8-K, filed on January 30, 2019)](https://www.sec.gov/Archives/edgar/data/1519061/000155837019000291/ex-10d1.htm)\n\n​\n\n​\n\n​\n\n10.20*\n\n​\n\n[Amendment, dated May 9, 2022, to the Employment Agreement between Trinseo LLC and Frank Bozich dated December 11, 2018 (incorporated by reference to Exhibit 10.1 to the Quarterly Report on Form 10-Q for the quarter ended June 30, 2022 filed August 9, 2022)](https://www.sec.gov/Archives/edgar/data/1519061/000155837022012794/tse-20220630xex10d1.htm)\n\n​\n\n​\n\n​\n\n10.21*\n\n​\n\n[Employment Agreement between Trinseo LLC and David Stasse, dated April 29, 2019 (incorporated herein by reference to Exhibit 10.1 to the Current Report on Form 8-K, filed on April 30, 2019)](https://www.sec.gov/Archives/edgar/data/1519061/000155837019003514/ex-10d1.htm)\n\n​\n\n​\n\n​\n\n10.22*\n\n​\n\n[Amendment, dated May 9, 2022, to the Employment Agreement between Trinseo LLC and David Stasse dated April 29, 2019 (incorporated by reference to Exhibit 10.2 to the Quarterly Report on Form 10-Q for the quarter ended June 30, 2022 filed August 9, 2022)](https://www.sec.gov/Archives/edgar/data/1519061/000155837022012794/tse-20220630xex10d2.htm)\n\n​\n\n​\n\n​\n\n10.23*\n\n​\n\n[Agreement between Trinseo, LLC and Angelo Chaclas dated January 1, 2020 (incorporated herein by reference to Exhibit 10.1 to the Quarterly Report on Form 10-Q filed on May 8, 2020)](https://www.sec.gov/Archives/edgar/data/1519061/000155837020005970/tse-20200331xex10d1.htm)\n\n​\n\n​\n\n​\n\n10.24*\n\n​\n\n[Agreement, dated May 9, 2022, to the Employment Agreement between Trinseo LLC and Angelo Chaclas dated January 1, 2020 (incorporated by reference to Exhibit 10.3 to the Quarterly Report on Form 10-Q for the quarter ended June 30, 2022 filed August 9, 2022)](https://www.sec.gov/Archives/edgar/data/1519061/000155837022012794/tse-20220630xex10d3.htm)\n\n​\n\n​\n\n​\n\n10.25*\n\n​\n\n[Employment Agreement between Trinseo LLC and Paula Cooney, dated October 15, 2021 (incorporated by reference to Exhibit 10.1 to the Quarterly Report on Form 10-Q for the quarter ended March 31, 2023 filed May 5, 2023)](https://www.sec.gov/Archives/edgar/data/1519061/000155837023008238/tse-20230331xex10d1.htm)\n\n​\n\n​\n\n​\n\n10.26*\n\n​\n\n[Amendment, dated May 9, 2022, to the Employment Agreement between Trinseo LLC and Paula Cooney dated October 15, 2021 (incorporated by reference to Exhibit 10.2 to the Quarterly Report on Form 10-Q for the quarter ended March 31, 2023 filed May 5, 2023)](https://www.sec.gov/Archives/edgar/data/1519061/000155837023008238/tse-20230331xex10d2.htm)\n\n​\n\n​\n\n​\n\n10.27*\n\n​\n\n[Employment Agreement between Trinseo Europe GmbH and Francesca Reverberi dated October 1, 2021 (incorporated by reference to Exhibit 10.2 to the Company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2022 filed May 5, 2022)](https://www.sec.gov/Archives/edgar/data/1519061/000155837022007305/tse-20220331xex10d2.htm)\n\n​\n\n​\n\n​\n\n10.28*\n\n​\n\n[Amendment, dated May 9, 2022, to the Employment Agreement between Trinseo Europe GmbH and Francesca Reverberi dated October 1, 2021 (incorporated by reference to Exhibit 10.5 to the Quarterly Report on Form 10-Q for the quarter ended June 30, 2022 filed August 9, 2022)](https://www.sec.gov/Archives/edgar/data/1519061/000155837022012794/tse-20220630xex10d5.htm)\n\n​\n\n​\n\n​\n\n10.29§\n\n​\n\n[Amended and Restated Styron License Agreement, among The Dow Chemical Company, Dow Global Technologies Inc. and Trinseo LLC (f/k/a Styron LLC), dated as of June 17, 2010. (incorporated herein by reference to Exhibit 10.31 to Amendment No. 2 to the Registration Statement filed on Form S-4, File No. 333-191460, filed December 17, 2013)](https://www.sec.gov/Archives/edgar/data/1519061/000119312513474933/d546187dex1031.htm)\n\n​\n\n​\n\n​\n\n10.30*\n\n​\n\n[Form of Restoration and Elective Deferral Plan (incorporated herein by reference to Exhibit 10.35 to Amendment No. 2 to the Registration Statement on Form S-1, File No. 333-194561, filed May 5, 2014)](https://www.sec.gov/Archives/edgar/data/1519061/000119312514180684/d681018dex1035.htm)\n\n​\n\n​\n\n​\n\n10.31*\n\n​\n\n[Performance Award (PA) Plan (incorporated herein by reference to Exhibit 10.36 to Amendment No. 2 to the Registration Statement on Form S-1, File No. 333-194561, filed May 5, 2014)](https://www.sec.gov/Archives/edgar/data/1519061/000119312514180684/d681018dex1036.htm)\n\n​\n\n​\n\n​\n\n10.32*\n\n​\n\n[Trinseo PLC Amended and Restated 2014 Omnibus Incentive Plan (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed June 26, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000155837025008889/tse-20250625xex10d1.htm)\n\n​\n\n​\n\n​\n\n38\n\n[Table of Contents](#TOC)\n\n​\n\n**Exhibit No.**\n\n​\n\n**Description**\n\n10.33*\n\n​\n\n[Form of Indemnification Agreement for Directors and Officers (incorporated herein by reference to Exhibit 10.1 to the Quarterly Report on Form 10-Q for the quarter ended September 30, 2021, filed on November 8, 2021)](https://www.sec.gov/Archives/edgar/data/1519061/000155837021015008/tse-20210930xex10d1.htm)\n\n​\n\n​\n\n​\n\n10.34*\n\n​\n\n[Form of Restricted Stock Unit Agreement for Directors (incorporated herein by reference to Exhibit 10.33 to the Company’s Annual Report on Form 10-K for the year ended December 31, 2022, filed on February 27, 2023)](https://www.sec.gov/Archives/edgar/data/1519061/000155837023002165/tse-20221231xex10d33.htm)\n\n​\n\n​\n\n​\n\n10.35*\n\n​\n\n[Form of Restricted Stock Unit Award Agreement (incorporated by reference to Exhibit 10.3 to the Company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2024 filed May 9, 2024)](https://www.sec.gov/Archives/edgar/data/1519061/000155837024007569/tse-20240331xex10d3.htm)\n\n​\n\n​\n\n​\n\n10.36*\n\n​\n\n[Form of Performance Award Stock Unit Agreement (incorporated by reference to Exhibit 10.2 to the Quarterly Report on Form 10-Q for the quarter ended March 31, 2025, filed on May 8, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000155837025006909/tse-20250331xex10d2.htm)\n\n​\n\n​\n\n​\n\n10.37*\n\n​\n\n[Form of Non-statutory Stock Option Award Agreement (incorporated by reference to Exhibit 10.5 to the Company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2024 filed May 9, 2024)](https://www.sec.gov/Archives/edgar/data/1519061/000155837024007569/tse-20240331xex10d5.htm)\n\n​\n\n​\n\n​\n\n10.38*\n\n​\n\n[Form of Restricted Cash Unit Award Agreement (incorporated by reference to Exhibit 10.3 to the Quarterly Report on Form 10-Q for the quarter ended March 31, 2025, filed on May 8, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000155837025006909/tse-20250331xex10d3.htm)\n\n​\n\n​\n\n​\n\n10.39*\n\n​\n\n[Form of Restricted Stock Unit Award Agreement to certain former Arkema employees (incorporated herein by reference to Exhibit 10.3 to the Quarterly Report on Form 10-Q for the quarter ended September 30, 2021, filed on November 8, 2021)](https://www.sec.gov/Archives/edgar/data/1519061/000155837021015008/tse-20210930xex10d3.htm)\n\n​\n\n​\n\n​\n\n10.40*\n\n​\n\n[Form of Stock Option Award Agreement to certain former Arkema employees (incorporated herein by reference to Exhibit 10.4 to the Quarterly Report on Form 10-Q for the quarter ended September 30, 2021, filed on November 8, 2021)](https://www.sec.gov/Archives/edgar/data/1519061/000155837021015008/tse-20210930xex10d4.htm)\n\n​\n\n​\n\n​\n\n10.41*\n\n​\n\n[Form of Executive Side Letter for Equity Grants (incorporated by reference to Exhibit 10.7 to the Company’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2019, filed August 9, 2019)](https://www.sec.gov/Archives/edgar/data/1519061/000155837019007840/tse-20190630ex1070cbd30.htm)\n\n​\n\n​\n\n​\n\n10.42*\n\n​\n\n[Form of Retention Award Agreement (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed February 27, 2024).](https://www.sec.gov/Archives/edgar/data/1519061/000155837024001862/tse-20240221xex10d1.htm)\n\n​\n\n​\n\n​\n\n10.43*\n\n​\n\n[Form of Contingent Restricted Stock Unit Award Agreement (incorporated by reference to Exhibit 10.1 to the Quarterly Report on Form 10-Q for the quarter ended March 31, 2025, filed on May 8, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000155837025006909/tse-20250331xex10d1.htm)\n\n​\n\n​\n\n​\n\n10.44*\n\n​\n\n[Form of Conditional Retention Award Letter Agreement (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K dated January 6, 2026)](https://www.sec.gov/Archives/edgar/data/1519061/000110465926002698/tse-20260106xex99d1.htm)\n\n​\n\n​\n\n​\n\n19.1\n\n​\n\n[Trinseo PLC Insider Trading Policy (incorporated by reference to Exhibit 19.1 to the Company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2025, filed on May 8, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000155837025006909/tse-20250331xex19d1.htm)\n\n​\n\n​\n\n​\n\n21.1\n\n​\n\n[Subsidiaries of Trinseo PLC (incorporated by reference to Exhibit 21.1 to the Annual Report on Form 10-K for the year ended December 31, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465926027518/tse-20251231xex21d1.htm)\n\n​\n\n​\n\n​\n\n23.1\n\n​\n\n[Consent of Independent Registered Public Accounting Firm PricewaterhouseCoopers LLP (incorporated by reference to Exhibit 23.1 to the Annual Report on Form 10-K for the year ended December 31, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465926027518/tse-20251231xex23d1.htm)\n\n​\n\n​\n\n​\n\n23.2\n\n​\n\n[Consent of Independent Registered Public Accounting Firm Deloitte & Touche LLP (incorporated by reference to Exhibit 23.2 to the Annual Report on Form 10-K for the year ended December 31, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465926027518/tse-20251231xex23d2.htm)\n\n​\n\n​\n\n​\n\n31.1\n\n​\n\n[Certification of Chief Executive Officer Pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 (incorporated by reference to Exhibit 31.1 to the Annual Report on Form 10-K for the year ended December 31, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465926027518/tse-20251231xex31d1.htm)\n\n​\n\n​\n\n​\n\n39\n\n[Table of Contents](#TOC)\n\n​\n\n**Exhibit No.**\n\n​\n\n**Description**\n\n31.2\n\n​\n\n[Certification of Chief Financial Officer Pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 (incorporated by reference to Exhibit 31.2 to the Annual Report on Form 10-K for the year ended December 31, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465926027518/tse-20251231xex31d2.htm)\n\n​\n\n​\n\n​\n\n31.3 †\n\n​\n\n[Certification of Chief Executive Officer Pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002](tse-20251231xex31d3.htm)\n\n​\n\n​\n\n​\n\n31.4 †\n\n​\n\n[Certification of Chief Financial Officer Pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002](tse-20251231xex31d4.htm)\n\n​\n\n​\n\n​\n\n32.1\n\n​\n\n[Certification of Chief Executive Officer Pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (incorporated by reference to Exhibit 32.1 to the Annual Report on Form 10-K for the year ended December 31, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465926027518/tse-20251231xex32d1.htm)\n\n​\n\n​\n\n​\n\n32.2\n\n​\n\n[Certification of Chief Financial Officer Pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (incorporated by reference to Exhibit 32.2 to the Annual Report on Form 10-K for the year ended December 31, 2025)](https://www.sec.gov/Archives/edgar/data/1519061/000110465926027518/tse-20251231xex32d2.htm)\n\n​\n\n​\n\n​\n\n97.1\n\n​\n\n[Trinseo PLC Policy for Recoupment of Incentive Compensation (incorporated by reference to Exhibit 97.1 to the Company’s Annual Report on Form 10-K for the year ended December 31, 2023).](https://www.sec.gov/Archives/edgar/data/1519061/000155837024001604/tse-20231231xex97d1.htm)\n\n​\n\n​\n\n​\n\n101.INS †\n\n​\n\niXBRL Instance Document\n\n​\n\n​\n\n​\n\n101.SCH †\n\n​\n\niXBRL Taxonomy Extension Schema Document\n\n​\n\n​\n\n​\n\n101.CAL †\n\n​\n\niXBRL Taxonomy Extension Calculation Linkbase Document\n\n​\n\n​\n\n​\n\n101.DEF †\n\n​\n\niXBRL Taxonomy Extension Definition Linkbase Document\n\n​\n\n​\n\n​\n\n101.LAB †\n\n​\n\niXBRL Extension Label Linkbase Document\n\n​\n\n​\n\n​\n\n101.PRE †\n\n​\n\niXBRL Taxonomy Extension Presentation Linkbase Document\n\n​\n\n​\n\n​\n\n104 †\n\n​\n\nCover Page Interactive Data File (formatted iXBRL and contained in Exhibit 101)\n\n​\n\n*\n\nCompensatory plan or arrangement.\n\n§\n\nApplication has been made to the SEC for confidential treatment of certain provisions of these exhibits. Omitted material for which confidential treatment has been requested has been filed separately with the SEC.\n\n§§ Certain portions of this exhibit were redacted pursuant to Item 601(b)(10)(iv) of Regulation S-K. The omitted information is (i) not material and (ii) would likely cause us competitive harm if publicly disclosed. We agree to furnish supplementally an unredacted copy of the exhibit to the Securities and Exchange Commission on its request; provided, however that the Company may request confidential treatment of this exhibit pursuant to Rule 24b-2 of the Securities Exchange Act of 1934, as amended.\n\n†\n\nFiled herewith.\n\n​\n\n40\n\n[Table of Contents](#TOC)\n\nSIGNATURES\n\nPursuant to the requirements of Section 13 or 15(d) of the Securities Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.\n\nDate: April 27, 2026\n\nTRINSEO PLC\n\n​\n\n​\n\n​\n\n​\n\nBy:\n\n/s/ Frank Bozich\n\n​\n\nName:\n\nFrank Bozich\n\n​\n\nTitle:\n\nPresident and Chief Executive Officer\n\n(Principal Executive Officer)\n\n​\n\n​\n\n​\n\n​\n\n​\n\n​\n\n​\n\n41"}