No. 10231X Form W-9 (Rev. 10-2018) AVIENT CORPORATION AVIENT COLORANTS USA LLC ✔ 5 E 33587 WALKER ROAD AVON LAKE, OH 44012 3 4 1 7 3 0 4 8 8 1/15/2021 Form W-9 (Rev. 10-2018) Page 2 By signing the filled-out form, you: 1. Partnerships that conduct a trade or business in the United States are generally required to pay a withholding tax under section 1446 on any foreign partners’ share of effectively connected taxable income from such business. In the cases below, the following person must give Form W-9 to the partnership for purposes of establishing its U.S. status and avoiding withholding on its allocable share of net income from the partnership conducting a trade or business in the United States

Patterson, Chairman, President and Chief Executive Officer, Avient Corporation. In addition, it has been just over a year since we acquired Clariant Masterbatch and we became Avient. About Avient Avient Corporation (NYSE: AVNT), with expected 2021 revenues of $4.6 to $4.7 billion, provides specialized and sustainable material solutions that transform customer challenges into opportunities, bringing new products to life for a better world.

Ashish Khandpur, President and Chief Executive Officer, Avient Corporation. Webcast Details Avient will host a webcast on Tuesday, May 7, 2024 at 8:00 a.m. To access Avient’s news library online, please visit www.avient.com/news-events.

Patterson, Chairman, President and Chief Executive Officer, Avient Corporation. 1 Mr. About Avient Avient Corporation (NYSE: AVNT), with 2020 pro forma revenues of $3.8 billion, provides specialized and sustainable material solutions that transform customer challenges into opportunities, bringing new products to life for a better world. Rose Vice President, Corporate Communications +1 440-930-3162 kyle.rose@avient.com 5 Attachment 1 Avient Corporation Summary of Condensed Consolidated Statements of Income (Unaudited) Year Ended Sales $ 997.0 $ 658.6 $ 3,242.1 $ 2,862.7 Operating Income 65.0 20.5 189.3 156.8 Net income from continuing operations attributable to Avient shareholders 74.2 6.4 132.0 75.5 Basic earnings per share from continuing operations attributable to Avient shareholders $ 0.81 $ 0.08 $ 1.47 $ 0.98 Diluted earnings per share from continuing operations attributable to Avient shareholders $ 0.81 $ 0.08 $ 1.46 $ 0.97 Senior management uses comparisons of adjusted net income from continuing operations attributable to Avient shareholders and diluted adjusted earnings per share (EPS) from continuing operations attributable to Avient shareholders, excluding special items, to assess performance and facilitate comparability of results.

1 (3) Pending matter(s) The register indicates pending matter(s) regarding a change to the registered information at the time this certificate was created. 2 (3) Registration number: 516411-5031 Business name: Avient S.à r.l., Sweden Filial Address: Drottninggatan 56 411 07 GÖTEBORG County and municipality: Västra Götaland, Göteborg Note: MANAGING DIRECTOR 630516 Palm, Christoph, Gruss Strooss 35, L-9991 WEISWAMPACH, LUXEMBURG AUDITORS 556053-5873 Ernst & Young Aktiebolag, Box 7850, 103 99 STOCKHOLM Represented by: 850807-5135 PRINCIPALLY RESPONSIBLE AUDITOR 850807-5135 Edman, Mikael Thomas Gunnar, c/o Ernst & Young AB, 401 82 GÖTEBORG SIGNATORY POWER Signatory power alone by Palm, Christoph FINANCIAL YEAR Registered financial year: 0101 - 1231 DATE OF REGISTRATION OF CURRENT AND PREVIOUS BUSINESS NAMES 2021-11-29 Avient S.à r.l., Sweden Filial 2018-08-28 PolyOne S.à.r.l., Sweden Filial INFORMATION ABOUT THE FOREIGN COMPANY B226205 Avient S.á.r.l. 19, Route de Bastogne L-9638 Pommerloch LUXEMBURG Registered office of the foreign company: Pommerloch Name of the register in which the foreign company is registered: 3 (3) RCS, Registre de Commerce, Luxembourg Business Register LUXEMBURG Foreign company's financial year: 0101 - 1231 The above information is an extract from the Trade and Industry Register Bolagsverket, the Swedish Companies Registration Office.

+358 (0)29 509 5000 registry@prh.fi Page: 1 (2) Business ID: 2046676-4 Date and time of creating the document: 01.12.2020 08:37:55 TRANSLATION OF THE EXTRACT FROM THE TRADE REGISTER, ELECTRONIC 01.12.2020 08:37:54 the details in the register Identifiers Name Avient Finland Oy Business ID 2046676-4 Entered in the register 31.03.2007 Company type Limited company Contact details: Postal address Äyritie 8 E 01510 Vantaa Street address Äyritie 8 E 01510 Vantaa Email tina.ahlquist@clariant.com Telephone 0106808500 Fax 0106808509 Name details Name Avient Finland Oy Auxiliary company name Drycolor Registered office Vantaa Share capital Share capital 169.000,00 € Number of shares 1 000 pcs Nominal value of a share 169,00 € Financial period Financial period 01.01 - 31.12 Financial statements The last financial statements submitted 01.01.2019 - 31.12.2019 Representation Page: 2 (2) Business ID: 2046676-4 Statutory representation: Under the law, the Board of Directors represents the company. Representation based on position: By the Chair of the Board and the Managing Director, each on their own, and by any two Board members jointly Persons role surname, first name(s) / company name date of birth / identity code citizenship Chair of the Board of Merklein, Norbert 03.05.1964 Citizen of Germany Norén, Jenny Eva Kristina 18.06.1975 Citizen of Sweden Smeds, Jan-Håkan 22.03.1961 Citizen of Finland Vetter, Alexander Helmut 04.07.1968 Citizen of Germany Managing Director Norén, Jenny Eva Kristina 18.06.1975 Citizen of Sweden Auditor PricewaterhouseCoopers Oy 0486406-8 Auditor with principal responsibility Grönroos, Maria Alice 19.02.1967 Citizen of Finland Additional information No details about beneficial owners have been registered for the company Name history Avient Finland Oy 01.12.2020 - Clariant Plastics & Coatings (Finland) Oy 04.01.2016 - 01.12.2020 Clariant Masterbatches (Finland) Oy 31.03.2007 - 04.01.2016 Source of information: Finnish Patent and Registration Office