Item 9A. Controls and Procedures

We maintain disclosure controls and procedures designed to ensure that information required to be disclosed in reports we file with the SEC is recorded, processed, summarized and reported within applicable time periods. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by us in the reports we file or submit under the Exchange Act, is accumulated and communicated to management, including our Chief Executive Officer, or CEO, and Chief Financial Officer, or CFO, as appropriate to allow timely decisions regarding required disclosure. Management, including our CEO and CFO, conducted an evaluation of the effectiveness of our disclosure controls and procedures as of December 31, 2025. Based on that evaluation, our CEO and CFO concluded that, as of December 31, 2025, our disclosure controls and procedures are effective to ensure that decisions can be made timely with respect to required disclosures, as well as ensuring that the recording, processing, summarization and reporting of information required to be included in our Annual Report on Form 10-K for the year ended December 31, 2025 are appropriate.

Our management is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Exchange Act Rule 13a-15(f). Management, with the participation of our CEO, CFO and our agencies, conducted an evaluation of the effectiveness of our internal control over financial reporting based on the framework in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission. Based on that evaluation, our CEO and CFO concluded that our internal control over financial reporting was effective as of December 31, 2025.

Omnicom management excluded IPG from its assessment of the effectiveness of Omnicom’s internal control over financial reporting as of December 31, 2025, in accordance with SEC staff guidance allowing management to exclude a recently acquired business from management’s report on internal control over financial reporting. IPG constituted 6% of total revenue for the year ended December 31, 2025 and 31% of total assets, excluding acquired goodwill and other intangible assets, as of December 31, 2025.

There have not been any changes in our internal control over financial reporting during our most recent fiscal quarter that have materially affected or are reasonably likely to materially affect our internal control over financial reporting.

KPMG LLP, an independent registered public accounting firm that audited our consolidated financial statements included in this Annual Report on Form 10-K, has issued an attestation report on Omnicom’s internal control over financial reporting as of December 31, 2025, dated February 20, 2026, which is included on page F-2 of this 2025 10-K.