On February 22, 2024, the Board of Directors of Vertex, Inc. (the Company) approved the appointment of Ryan Leib as Principal Accounting Officer effective upon Lisa Butler?s retirement on March 15, 2024. Ms. Butler will work with Mr. Leib to ensure a smooth and orderly transition of responsibilities. Mr. Leib, age 46, joined the Company in January 2024 as its prospective Chief Accounting Officer.

Mr. Leib will be appointed as the Company?s Chief Accounting Officer on March 15, 2024. Prior to that, he most recently served as the Vice President of M&A and Portfolio Transformation at Trinseo PLC (Trinseo) from January 2022 to January 2024. Mr. Leib?s tenure at Trinseo dates back to 2013 where he previously held roles as Vice President and Treasurer, Vice President, Global Controller and Principal Accounting Officer, Corporate Controller, and Assistant Corporate Controller.

Earlier in his career, Mr. Leib worked at PricewaterhouseCoopers as a senior audit manager. Mr. Leib earned a bachelor?s degree in Accounting from Saint Joseph?s University and is a certified public accountant.