Omnicom Group Inc.

Commission File Number: 1-10551 OMNICOM GROUP INC. (Exact name of registrant as specified in its charter) New York 13-1514814 (State or other jurisdiction of incorporation or organization) (IRS Employer Identification No.) 280 Park Avenue , New York , NY 10017 (Address of principal executive offices) (Zip Code)

Registrant's telephone number, including area code: ( 212 ) 415-3600 Not Applicable (Former name, former address and former fiscal year, if changed since last report)

OMNICOM GROUP INC. QUARTERLY REPORT ON FORM 10-Q FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30, 2026 TABLE OF CONTENTS PART I. FINANCIAL INFORMATION Page Item 1. Financial Statements Consolidated Balance Sheets - September 30, 2026 and December 31, 2025 1 Consolidated Statements of Income - Three and Nine Months Ended September 30, 2026 and 2025 2 Consolidated Statements of Comprehensive Income - Three and Nine Months Ended September 30, 2026 and 2025 3 Consolidated Statements of Equity - Three and Nine Months Ended September 30, 2026 and 2025 4

Consolidated Statements of Cash Flows - Nine Months Ended September 30, 2026 and 2025 5 Notes to Consolidated Financial Statements 6 Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations 17 Forward-Looking Statements 17 Executive Summary 18 Consolidated Results of Operations 22 Non-GAAP Financial Measures 29 Liquidity and Capital Resources 30 Critical Accounting Estimates 33 Item 3. Quantitative and Qualitative Disclosures About Market Risk 35 Item 4. Controls and Procedures 35 PART II. OTHER INFORMATION Item 1. Legal Proceedings 36 Item 1A. Risk Factors 36 Item 2. Unregistered Sales of Equity Securities and Use of Proceeds 36 Item 5. Other Information 36 Item 6. Exhibits 37 Signatures 37

PART I. FINANCIAL INFORMATION Item 1. Financial Statements OMNICOM GROUP INC. AND SUBSIDIARIES CONSOLIDATED BALANCE SHEETS (In millions) September 30, 2026 December 31, 2025 (Unaudited) ASSETS: Current Assets: Cash and cash equivalents $ 3,796.4 $ 6,881.1 Accounts receivable, net of allowance for doubtful accounts of $ 9.7 and $ 11.9 13,223.6 14,398.0 Work in process 3,825.7 3,408.9 Assets held for sale 490.8 1,012.2 Other current assets 2,011.0 1,765.2 Total Current Assets 23,347.5 27,465.4 Property and Equipment at cost, less accumulated depreciation of $ 1,190.8 and $ 1,386.8 973.3 1,010.3 Operating Lease Right-Of-Use Assets 1,160.5 1,379.8 Equity Method Investments 56.7 65.9 Goodwill 18,608.8 18,641.4 Intangible Assets, net of accumulated amortization of $ 1,107.5 and $ 903.2 4,743.2 5,101.0 Other Assets 786.5 751.5 TOTAL ASSETS $ 49,676.5 $ 54,415.3 LIABILITIES AND EQUITY: Current Liabilities: Accounts payable $ 18,148.8 $ 20,659.5 Customer advances 2,308.2 1,727.6 Current portion of debt 568.3 1,399.5 Short-term debt 60.5 62.0 Taxes payable 125.0 264.9 Liabilities held for sale 684.7 1,261.0 Other current liabilities 3,626.8 4,163.7 Total Current Liabilities 25,522.3 29,538.2 Long-Term Liabilities 1,230.7 1,099.5 Long-Term Liability - Operating Leases 1,342.7 1,617.0 Long-Term Debt 9,389.5 7,655.0 Deferred Tax Liabilities 1,598.5 1,449.4 Commitments and Contingent Liabilities (Note 13) Temporary Equity - Redeemable Noncontrolling Interests 266.9 363.2 Equity: Shareholders' Equity: Preferred stock - - Common stock 63.2 63.2 Additional paid-in capital 9,525.9 9,424.4 Retained earnings 11,757.8 10,782.4 Accumulated other comprehensive income (loss) ( 1,264.2 ) ( 1,265.8 ) Treasury stock, at cost ( 10,131.9 ) ( 6,958.4 ) Total Shareholders' Equity 9,950.8 12,045.8 Noncontrolling interests 375.1 647.2 Total Equity 10,325.9 12,693.0 TOTAL LIABILITIES AND EQUITY $ 49,676.5 $ 54,415.3

The accompanying notes to the consolidated financial statements are an integral part of these statements. 1

OMNICOM GROUP INC. AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (In millions, except per share amounts) Three Months Ended September 30, Nine Months Ended September 30, 2026 2025 2026 2025 Revenue $ 6,422.8 $ 4,037.1 $ 19,228.2 $ 11,743.1 Operating Expenses: Salary and service costs 4,586.4 2,921.5 13,939.3 8,600.4 Occupancy and other costs 499.3 322.7 1,531.0 963.2 Severance and repositioning costs 84.7 38.6 135.8 127.4 Net (gain) loss on assets held for sale and dispositions ( 106.8 ) - ( 72.5 ) - Cost of services 5,063.6 3,282.8 15,533.6 9,691.0 Selling, general and administrative expenses 200.9 163.5 634.4 451.8 Depreciation and amortization 166.6 60.7 499.8 178.4 Total Operating Expenses 5,431.1 3,507.0 16,667.8 10,321.2 Operating Income 991.7 530.1 2,560.4 1,421.9 Interest Expense 132.8 60.4 375.0 182.1 Interest Income 28.6 17.2 105.5 68.8 Income Before Income Taxes and Income From Equity Method Investments 887.5 486.9 2,290.9 1,308.6 Income Tax Expense 215.4 132.3 594.8 373.5 Income From Equity Method Investments 2.5 5.8 2.7 6.5 Net Income 674.6 360.4 1,698.8 941.6 Net Income Attributed To Noncontrolling Interests 18.6 19.1 52.8 55.0 Net Income - Omnicom Group Inc. $ 656.0 $ 341.3 $ 1,646.0 $ 886.6 Net Income Per Share - Omnicom Group Inc.: Basic $ 2.39 $ 1.76 $ 5.80 $ 4.54 Diluted $ 2.38 $ 1.75 $ 5.77 $ 4.51 Weighted Average Shares: Basic 274.0 193.8 284.0 195.2 Diluted 275.4 194.9 285.2 196.4

The accompanying notes to the consolidated financial statements are an integral part of these statements. 2

OMNICOM GROUP INC. AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (In millions) Three Months Ended September 30, Nine Months Ended September 30, 2026 2025 2026 2025 Net Income $ 674.6 $ 360.4 $ 1,698.8 $ 941.6 Other Comprehensive Income (Loss): Cash flow hedge: Amortization of loss included in interest expense - 1.3 1.3 4.1 Income tax effect - ( 0.4 ) ( 0.4 ) ( 1.3 ) Cash flow hedge, net of tax - 0.9 0.9 2.8 Pension and other postemployment benefits: Amortization of prior service cost 1.8 1.7 5.4 5.1 Amortization of actuarial losses ( 0.6 ) 0.2 ( 1.7 ) 0.7 Income tax effect ( 0.5 ) ( 1.4 ) ( 2.9 ) ( 4.4 ) Pension plans and other postemployment benefits, net of tax 0.7 0.5 0.8 1.4 Foreign currency translation adjustment 33.2 ( 60.6 ) ( 3.6 ) 155.2 Other Comprehensive Income (Loss) 33.9 ( 59.2 ) ( 1.9 ) 159.4 Comprehensive Income 708.5 301.2 1,696.9 1,101.0 Comprehensive Income Attributed To Noncontrolling Interests 19.1 16.1 49.3 65.6 Comprehensive Income - Omnicom Group Inc. $ 689.4 $ 285.1 $ 1,647.6 $ 1,035.4

The accompanying notes to the consolidated financial statements are an integral part of these statements.

The accompanying notes to the consolidated financial statements are an integral part of these statements.

OMNICOM GROUP INC. AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (In millions) Nine Months Ended September 30, 2026 2025 Cash Flows From Operating Activities: Net income $ 1,698.8 $ 941.6 Adjustments to reconcile net income to net cash provided by (used in) operating activities: Depreciation and amortization of right-of-use assets 144.6 103.4 Amortization of intangible assets 355.2 75.0 Share-based compensation 83.3 73.1 Severance and repositioning costs 135.8 127.4 Net (gain) loss on assets held for sale and dispositions ( 72.5 ) - Other, net 8.0 3.1 Use of operating capital ( 2,315.4 ) ( 1,422.8 ) Net Cash Provided By (Used In) Operating Activities 37.8 ( 99.2 ) Cash Flows From Investing Activities: Capital expenditures ( 172.8 ) ( 110.7 ) Acquisition of businesses and interests in affiliates, net of cash acquired ( 7.1 ) ( 0.8 ) Proceeds from assets held for sale and dispositions 413.9 - Other, net - 50.7 Net Cash Provided By (Used In) Investing Activities 234.0 ( 60.8 ) Cash Flows From Financing Activities: Proceeds from borrowings 2,384.9 - Repayment of debt ( 1,400.0 ) - Change in short-term debt 2.1 0.5 Dividends paid to common shareholders ( 703.3 ) ( 413.9 ) Repurchases of common stock ( 3,210.3 ) ( 312.1 ) Proceeds from stock plans 45.0 18.0 Acquisition of additional noncontrolling interests ( 288.5 ) ( 39.0 ) Dividends paid to noncontrolling interest shareholders ( 60.2 ) ( 57.1 ) Payment of contingent purchase price obligations ( 7.9 ) ( 47.9 ) Other, net ( 60.8 ) ( 56.0 ) Net Cash Provided By (Used In) Financing Activities ( 3,299.0 ) ( 907.5 ) Effect of foreign exchange rate changes on cash and cash equivalents ( 57.5 ) 134.6 Net Increase (Decrease) in Cash and Cash Equivalents ( 3,084.7 ) ( 932.9 ) Cash and Cash Equivalents at the Beginning of Period 6,881.1 4,339.4 Cash and Cash Equivalents at the End of Period $ 3,796.4 $ 3,406.5

The accompanying notes to the consolidated financial statements are an integral part of these statements.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)

1) Revenue for the three and nine months ended September 30, 2026 includes amounts attributable to disposals or entities classified as held for sale, consisting of $ 412.1 million and $ 1.6 billion, respectively. Economic factors affecting our revenue Global economic conditions and disruptions directly impact our revenue. Adverse economic conditions and disruptions pose a risk that our clients may reduce, postpone, or cancel spending for our services, which would impact our revenue. Revenue by geographic market: Three Months Ended September 30, Nine Months Ended September 30, 2026 2025 2026 2025 Americas: North America $ 3,966.1 $ 2,245.3 $ 11,842.0 $ 6,566.5 Latin America 238.2 126.4 682.8 337.4 EMEA: Europe 1,452.0 1,135.4 4,478.6 3,296.7 Middle East and Africa 160.0 67.4 445.9 204.4 Asia-Pacific 606.5 462.6 1,778.9 1,338.1 Revenue 1 $ 6,422.8 $ 4,037.1 $ 19,228.2 $ 11,743.1

1) Revenue for the three and nine months ended September 30, 2026 includes amounts attributable to disposals or entities classified as held for sale, consisting of $ 412.1 million and $ 1.6 billion, respectively. The Americas is comprised of North America, which includes the United States, Canada and Puerto Rico, and Latin America, which includes South America and Mexico. EMEA is comprised of Europe, the Middle East and Africa. Asia-Pacific includes Australia, Greater China, India, Japan, Korea, New Zealand, Singapore and other Asian countries. Revenue in the United States for the three months ended September 30, 2026 and 2025 was $ 3.8 billion and $ 2.1 billion, respectively, and revenue in the United States for the nine months ended September 30, 2026 and 2025 was $ 11.3 billion and $ 6.2 billion, respectively. Contract balances Contract balances include work in process and customer advances that primarily consist of advance billings to customers in accordance with the terms of the client contracts, primarily for the reimbursement of third-party costs. September 30, 2026 December 31, 2025 September 30, 2025 Work in process: Media and production costs $ 2,055.8 $ 2,200.1 $ 908.3 Unbilled fees and costs and contract assets 1,769.9 1,208.8 1,115.2 Work in process $ 3,825.7 $ 3,408.9 $ 2,023.5 Customer advances $ 2,308.2 $ 1,727.6 $ 1,273.0

There were no impairment charges recorded in work in process in the nine months ended September 30, 2026 and 2025. The majority of our contracts are for periods of one year or less, with the exception of our data management contracts. For those contracts with a term of more than one year, we had approximately $ 426.0 million of unsatisfied performance obligations as of September 30, 2026, which will be recognized as services are performed over the remaining contractual terms through 2030. 7

3. Net Income per Share Basic and diluted net income per share: Three Months Ended September 30, Nine Months Ended September 30, 2026 2025 2026 2025 Net Income - Omnicom Group Inc. $ 656.0 $ 341.3 $ 1,646.0 $ 886.6

Weighted Average Shares (millions): Basic 274.0 193.8 284.0 195.2 Dilutive stock options and restricted shares 1.4 1.1 1.2 1.2 Diluted 275.4 194.9 285.2 196.4 Anti-dilutive stock options and restricted shares (millions) 6.0 5.8 6.0 5.8 Net Income per Share - Omnicom Group Inc.: Basic $ 2.39 $ 1.76 $ 5.80 $ 4.54 Diluted $ 2.38 $ 1.75 $ 5.77 $ 4.51

The number of potential shares of common stock excluded from diluted shares outstanding was 6.0 million for each of the three and nine months ended September 30, 2026 and 5.8 million for each of the three and nine months ended September 30, 2025, because their inclusion would have been anti-dilutive. The increase in our weighted average shares in 2026 was primarily due to the inclusion of shares issued in connection with the Merger, partially offset by share repurchases, including shares repurchased pursuant to the accelerated share repurchase program. See Note 5 to the consolidated financial statements. 4. Goodwill and Intangible Assets Change in goodwill: Nine Months Ended September 30, 2026 2025 January 1 $ 18,641.4 $ 10,677.4 Acquisitions 1 177.5 2.5 Noncontrolling interests in acquired businesses 13.5 2.6 Contingent purchase price obligations of acquired businesses 13.5 2.6 Dispositions ( 195.7 ) ( 66.3 ) Foreign currency translation ( 41.4 ) 296.4 September 30 $ 18,608.8 $ 10,915.2

1) The increase in goodwill in the nine months ended September 30, 2026 is primarily due to adjustments to the preliminary purchase price accounting for the Merger in November 2025 (see Note 5 to the consolidated financial statements). There were no goodwill impairment charges recorded in the nine months ended September 30, 2026 or 2025, and we have no accumulated goodwill impairment charges. We completed our annual goodwill impairment test as of May 1, 2026. The market assumptions used in our assessment reflect the current economic environment (see Note 1 to the consolidated financial statements). Based on our impairment test results, we concluded that our goodwill was not impaired as of May 1, 2026. No events or circumstances through September 30, 2026 would change our impairment assessment. Intangible assets: September 30, 2026 December 31, 2025 Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value

Amortization of intangible assets: Three Months Ended September 30, Nine Months Ended September 30, 2026 2025 2026 2025 Acquired intangible assets and internally developed strategic platform assets $ 112.9 $ 21.5 $ 334.5 $ 63.1 Other purchased and internally developed software 7.2 3.9 20.7 11.9 Amortization Expense $ 120.1 $ 25.4 $ 355.2 $ 75.0

5. Business Combinations On November 26, 2025, we completed the Merger (see Note 1 to the consolidated financial statements). The acquisition combines complementary capabilities and service offerings and is expected to expand client opportunities and support long-term growth. Purchase Consideration Pursuant to the merger agreement between Omnicom and IPG, the 361,498,876 shares of IPG common stock (the "IPG common stock") (par value $0.10 per share) that were issued and outstanding immediately prior to the Merger were converted into 124,352,188 shares of Omnicom common stock (par value $0.15 per share) and cash in lieu of fractional shares, based on an exchange ratio (the "Exchange Ratio") of 0.344 shares of Omnicom common stock for each share of IPG common stock. Following the closing of the Merger, legacy Omnicom shareholders owned approximately 60.6% of the combined company, and legacy IPG shareholders owned approximately 39.4%, on a fully diluted basis. The total consideration paid at closing was $ 8,893.5 million, consisting primarily of equity consideration of $ 8,891.2 million, excluding debt assumed in connection with Omnicom's offer to exchange all outstanding notes of certain series issued by IPG. The following table summarizes the purchase consideration: Fair value of shares issued to IPG shareholders 1 $ 8,891.2 Cash paid for fractional shares $ 0.3 Fair value of equity awards 2 $ 2.0 Total Consideration $ 8,893.5

1) The fair value of shares issued reflects the number of IPG shares outstanding at the Closing Date multiplied by the Exchange Ratio and Omnicom's closing share price on the Closing Date. 2) Represents the fair value of director awards that were settled as part of the closing consideration through the issuance of shares and assumed stock option awards. Preliminary Purchase Price Allocation The following table summarizes the preliminary fair values of the tangible and identifiable assets acquired and liabilities assumed as of the Closing Date: Cash and cash equivalents $ 1,080.6 Accounts payable $ 7,066.8 Accounts receivable 5,749.5 Customer advances 715.8 Work in process 2,227.3 Short-term debt 42.4 Assets held for sale 262.4 Liabilities held for sale 106.5 Other current assets 563.2 Other current liabilities 1,700.4 Property and equipment 251.6 Long-term liabilities 432.9 Operating lease right-of-use assets 595.5 Long-term liability - operating leases 876.4 Equity method investments 32.1 Long-term debt 2,764.9 Intangible assets 4,575.6 Deferred tax liabilities, net 1,093.3 Other assets 705.8 Non-controlling interests 211.7 Total Assets $ 16,043.6 Redeemable non-controlling interest 8.4 Total Liabilities and Non-controlling interest $ 15,019.5

Fair value of net assets acquired $ 1,024.1 Goodwill 7,869.4 Total Consideration $ 8,893.5

The purchase accounting process has not been completed as of September 30, 2026, including the finalization of the purchase price allocation. The Company has not yet finalized the valuation of certain assets acquired and liabilities assumed, including identifiable intangible assets. The preliminary fair values of identifiable assets as of September 30, 2026 include Trade Names of $ 792.0 million, Customer Relationships of $ 3.6 billion, and Technology and Other of $ 167.7 million. During the nine months ended September 30, 2026, the adjustments to goodwill related primarily to the updates of the fair value of acquired software and deferred taxes. The purchase price allocation may be adjusted during the measurement period, which will not exceed one year from the Closing Date. Integration and Acquisition-Related Costs During the three and nine months ended September 30, 2026, the Company incurred approximately $ 40.4 million and $ 139.9 million, respectively, of integration related costs associated primarily with the acquisition of IPG. During the three and nine months ended September 30, 2025, the Company incurred approximately $ 60.8 million and $ 160.6 million, respectively, of acquisition related costs associated primarily with the acquisition of IPG. These costs consist mainly of third-party professional fees and were recorded within selling, general and administrative expenses in the consolidated statements of income. The Company may incur additional integration costs in the future related to the acquisition of IPG. 6. Debt Credit Facility On November 26, 2025, in connection with the Merger, the Company entered into a Fourth Amended and Restated Five Year Credit Agreement (the "Credit Agreement Amendment"), which amended and restated the Company's Third Amended and Restated Five Year Credit Agreement, dated as of June 2, 2023. The Credit Agreement Amendment, among other things, (i) increased the unsecured multi-currency revolving credit facility (the "Credit Facility") amount from $2.5 billion to $ 3.5 billion, (ii) reduced the facility fee and applicable margin, (iii) extended the termination date (with respect to the available commitments of the extending lenders) from June 2, 2028 to November 26, 2030 and (iv) designated Omnicom as sole borrower under the Credit Facility. We can issue up to $ 3.0 billion of U.S. Dollar denominated commercial paper under a U.S. commercial paper program, and issue up to the equivalent of $ 500 million in British Pounds or Euros under a Euro commercial paper program. In addition, certain of our subsidiaries have uncommitted credit lines that are guaranteed by Omnicom, aggregating $ 952.7 million. All of these facilities provide additional liquidity sources for operating capital and general corporate purposes. During the three months ended September 30, 2026, we issued commercial paper, and the average and maximum amounts outstanding during the quarter were $ 436.4 million and $ 730.0 million, respectively. During the nine months ended September 30, 2026, we issued commercial paper, and the average and maximum amounts outstanding were $ 244.7 million and $ 730.0 million, respectively. There were no issuances of commercial paper for the three and nine months ended September 30, 2025. At both September 30, 2026 and 2025, there were no outstanding commercial paper issuances. The Credit Facility has a financial covenant that requires us to maintain a Leverage Ratio (as defined in the Credit Facility) of consolidated indebtedness to consolidated EBITDA (earnings before interest, taxes, depreciation, amortization and non-cash charges) of no more than 3.5 times for the most recently ended 12-month period. At September 30, 2026, we were in compliance with this covenant as our Leverage Ratio, computed in accordance with the terms of the Credit Facility, was 2.3 times. The Credit Facility does not limit our ability to declare or pay dividends or repurchase our common stock. Short-Term Debt Short-term debt of $ 60.5 million and $ 62.0 million at September 30, 2026 and December 31, 2025, respectively, represented bank overdrafts and short-term borrowings primarily of our international subsidiaries.

On March 2, 2026, Omnicom closed its public offering of $ 400 million aggregate principal amount of 4.200 % Senior Notes due 2029, $ 700 million aggregate principal amount of 5.000 % Senior Notes due 2033 and $ 600 million aggregate principal amount of 5.300 % Senior Notes due 2036. In addition, on March 2, 2026, Omnicom Finance Holdings plc, a U.K.-based wholly owned subsidiary of Omnicom ("OFH"), closed its public offering of € 600 million aggregate principal amount of 3.850 % Senior Notes due 2034, which are fully and unconditionally guaranteed by Omnicom. Omnicom used a portion of the net proceeds of these offerings to repay its $ 1.4 billion 3.600 % Senior Notes due 2026, which were fully redeemed at par on March 13, 2026. Omnicom intends to use the remaining proceeds for general corporate purposes. Omnicom has fully and unconditionally guaranteed the obligations of OFH with respect to the € 500 million 0.800 % Senior Notes due 2027, the € 500 million 1.400 % Senior Notes due 2031, the € 600 million 3.700 % Senior Notes due 2032, and the € 600 million 3.850 % Senior Notes due 2034 (collectively, the "Euro Notes"). The € 500 million 0.800 % Senior Notes are due in July of 2027, and accordingly, have been reclassified to current liabilities on the balance sheet. OFH's assets consist of its investments in several wholly owned finance companies that function as treasury centers, providing funding for various operating companies in Europe, Australia, and other countries in the Asia-Pacific region. The finance companies' assets consist of cash and cash equivalents and intercompany loans that they make or have made to the operating companies in their respective regions and the related interest receivable. There are no restrictions on the ability of Omnicom or OFH to obtain funds from their subsidiaries through dividends, loans, or advances. The Euro Notes and the related guarantees are senior unsecured obligations that rank equal in right of payment with all existing and future unsecured senior indebtedness of OFH and Omnicom, respectively. Omnicom has fully and unconditionally guaranteed the obligations of Omnicom Capital Holdings plc ("OCH"), a U.K.-based wholly owned subsidiary of Omnicom, with respect to the £ 325 million aggregate principal amount of 2.250 % Senior Notes due 2033 (the "Sterling Notes"). OCH's assets consist of its investments in several wholly owned finance companies that function as treasury centers, providing funding for various operating companies in EMEA, Australia, and other countries in the Asia-Pacific region. The finance companies' assets consist of cash and cash equivalents and intercompany loans that they make or have made to the operating companies in their respective regions and the related interest receivable. There are no restrictions on the ability of 11

Omnicom or OCH to obtain funds from their subsidiaries through dividends, loans, or advances. The Sterling Notes and the related guarantee are senior unsecured obligations that rank equal in right of payment with all existing and future unsecured senior indebtedness of OCH and Omnicom, respectively. 7. Segment Reporting Our branded agency networks operate in the advertising, marketing and corporate communications services industry, and are organized into agency networks, virtual client networks, regional reporting units and operating groups or connected capabilities. Our networks, virtual client networks and agencies increasingly share clients and provide clients with integrated services. The main economic components of each agency are employee compensation and related costs, direct service costs and occupancy and other costs which include rent and occupancy costs, technology costs and overhead expenses. Therefore, given these similarities, we aggregate our four operating segments, which are our global agency networks, into one reporting segment. The Chief Operating Decision Maker, or CODM, reviews segment operating income for each network and allocates resources accordingly. Beginning in December of 2025, we integrated the newly acquired IPG businesses into our existing four networks. The CODM includes Omnicom's chief executive officer, chief financial officer and chief operating officer. Segment operating results include allocations of costs, including information technology, and other shared services costs, that are allocated using metrics designed to correlate the allocation with consumption. Segment revenue, segment operating expenses and segment operating income of our operating segments: Three Months Ended September 30, Nine Months Ended September 30, 2026 2025 2026 2025 Revenue $ 6,422.8 $ 4,037.1 $ 19,228.2 $ 11,743.1 Segment Operating Expenses: Salary and service costs: Salary and related costs $ 2,866.7 $ 1,778.5 $ 8,894.9 $ 5,386.8 Third-party service costs 1,508.0 955.6 4,396.1 2,670.8 Third-party incidental costs 211.7 187.4 648.3 542.8 Total salary and service costs 4,586.4 2,921.5 13,939.3 8,600.4 Occupancy and other costs 499.3 322.7 1,531.0 963.2 Segment cost of services 5,085.7 3,244.2 15,470.3 9,563.6 Selling, general and administrative expenses 160.5 102.7 494.5 291.2 Depreciation and amortization 166.6 60.7 499.8 178.4 Total segment operating expenses 5,412.8 3,407.6 16,464.6 10,033.2 Segment Operating Income $ 1,010.0 $ 629.5 $ 2,763.6 $ 1,709.9

Reconciliation of segment operating income to income before income taxes and income from equity method investments: Three Months Ended September 30, Nine Months Ended September 30, 2026 2025 2026 2025

Segment Operating Income $ 1,010.0 $ 629.5 $ 2,763.6 $ 1,709.9 Severance and repositioning costs 84.7 38.6 135.8 127.4 Net (gain) loss on assets held for sale and dispositions ( 106.8 ) - ( 72.5 ) - Integration and acquisition related costs 40.4 60.8 139.9 160.6 Operating Income 991.7 530.1 2,560.4 1,421.9 Interest Expense 132.8 60.4 375.0 182.1 Interest Income 28.6 17.2 105.5 68.8 Income Before Income Taxes and Income From Equity Method Investments $ 887.5 $ 486.9 $ 2,290.9 $ 1,308.6

We reconcile segment operating income to income before income taxes and income from equity method investments as income tax expense is reviewed at the consolidated level and the segment managers are not held accountable for performance of net income. The agency networks' regional reporting units comprise three principal regions: the Americas, EMEA and Asia-Pacific. The regional reporting units monitor the performance and are responsible for the agencies in their region. Agencies within the regional reporting units serve similar clients in similar industries and, in many cases, have the same clients and similar economic characteristics.

Revenue and long-lived assets and goodwill by geographic region: Americas EMEA Asia-Pacific September 30, 2026 Revenue - Three months ended $ 4,204.3 $ 1,612.0 $ 606.5 Revenue - Nine months ended $ 12,524.8 $ 4,924.5 $ 1,778.9 Long-lived assets and goodwill $ 13,651.3 $ 5,745.1 $ 1,346.2 September 30, 2025 Revenue - Three months ended $ 2,371.7 $ 1,202.8 $ 462.6 Revenue - Nine months ended $ 6,903.9 $ 3,501.1 $ 1,338.1 Long-lived assets and goodwill $ 8,083.0 $ 3,981.7 $ 716.5

8. Income Taxes Our effective tax rate for the nine months ended September 30, 2026 was 26.0 % compared to 28.5 % for the nine months ended September 30, 2025. The 2026 effective tax rate included the impact of favorable settlements of uncertain tax positions. The effective tax rates for both 2026 and 2025 reflect the impact of the lower tax benefit associated with severance and repositioning charges and IPG acquisition-related costs. Numerous foreign jurisdictions have enacted legislation to adopt a minimum effective tax rate described in the Global Anti-Base Erosion, or Pillar Two, model rules issued by the Organization for Economic Co-operation and Development ("OECD"). Under such rules, a minimum effective tax rate of 15% applies to multinational companies with consolidated revenue above €750 million. Under the Pillar Two rules, a company is required to determine a combined effective tax rate for all entities located in a jurisdiction. If the jurisdictional effective tax rate determined under the Pillar Two rules is less than 15%, a top-up tax will be due to bring the jurisdictional effective tax rate up to 15%. We are continuing to monitor Pillar Two legislative developments and the effects of Pillar Two on our business. On January