{"url_path":"/sec/tseof/8-k/2026-05-15/cover-page","section_key":"cover-page","section_title":"Cover Page","topic":"sec","document":{"doc_type":"8-K","doc_date":"2026-05-15","source_url":"https://www.sec.gov/Archives/edgar/data/1519061/0001104659-26-062804-index.html","accession_number":"0001104659-26-062804","cik":"0001519061","ticker":"TSEOQ","issuer_name":"Trinseo PLC","edgar_url":"https://www.sec.gov/Archives/edgar/data/1519061/0001104659-26-062804-index.html","primary_entity_key":"0001519061","primary_entity_name":"Trinseo PLC"},"word_count":443,"has_tables":true,"body_markdown":"false\n0001519061\n00-0000000\n\n0001519061\n\n2026-05-15\n2026-05-15\n\niso4217:USD\n\nxbrli:shares\n\niso4217:USD\n\nxbrli:shares\n\n \n\n \n\n \n\n**UNITED STATES** \n\n**SECURITIES\nAND EXCHANGE COMMISSION **\n\n**Washington,\nD.C. 20549**\n\n \n\n \n\n \n\n**FORM 8-K**\n\n \n\n \n\n \n\n**CURRENT REPORT**\n\n**Pursuant to Section 13\nor 15(d)**\n\n**of The Securities Exchange\nAct of 1934**\n\n \n\nDate of Report (Date of earliest event reported):\n**May 15, 2026**\n\n \n\n \n\n \n\n**Trinseo\nPLC**\n\n(Exact name of registrant\nas specified in its charter)\n\n \n\n \n\n \n\n**Ireland**\n \n**001-36473**\n \n**N/A**\n\n(State or other jurisdiction\n\nof incorporation or organization)\n \n(Commission\n\nFile Number)\n \n(I.R.S. Employer\n\nIdentification Number)\n\n \n\n**440\nEast Swedesford Road****, Suite 301****,**\n\n**Wayne****,\nPennsylvania****19087**\n\n(Address of principal\nexecutive offices, including zip code)\n\n \n\n**(610****) 240-3200**\n\n(Telephone number, including\narea code)\n\n \n\n \n\n \n\nCheck the appropriate box below if the Form 8-K\nfiling is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General\nInstruction A.2. below):\n\n \n\n¨Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)\n\n \n\n¨Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)\n\n \n\n¨Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))\n\n \n\n¨Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))\n\n \n\nSecurities registered pursuant to Section 12(b) of\nthe Act:\n\n \n\n**Title of Each\nClass**\n**Trading\nsymbol(s)**\n**Name of Each Exchange\non which registered**\n\nOrdinary Shares, par value $0.01 per share\nTSEOF\nN/A*\n\n \n\nIndicate by check mark whether the registrant\nis an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2\nof the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).\n\n \n\nEmerging growth\ncompany ¨\n\n \n\nIf an emerging\ngrowth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any\nnew or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨\n\n \n\n** On March 23, 2026, the NYSE filed a Form 25 relating to the delisting\nfrom the NYSE of our ordinary shares. The delisting became effective on March 30, 2026. The ordinary shares will continue to trade over\nthe counter under the symbol “TSEOF.”*\n\n \n\n \n\n \n\n \n\n \n\n \n\n**EXPLANATORY NOTE**\n\n** **\n\nThis Current Report is being filed to report an extension of the expiration\ndate of the waiver agreement (the “Existing Waiver”) previously disclosed under Item 1.01 of, and filed as an exhibit to,\nthe Current Report on Form 8-K filed by Trinseo PLC (the “Company”) with the U.S. Securities and Exchange Commission on March\n20, 2026 (the “Prior 8-K”). As permitted by the terms of the Existing Waiver, the Company received confirmations from the\ncounterparties extending the expiration date of the Existing Waiver as described below. No new waiver agreement was entered into in connection\nwith such extension."}