OMNICOM GROUP INC.

For a more complete understanding of our accounting estimates and policies, the unaudited consolidated financial statements and the related Management’s Discussion and Analysis of Financial Condition and Results of Operations, readers are encouraged to consider this information together with our discussion of our critical accounting policies under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our 2025 10-K.

Acquisitions and Goodwill

In addition to the IPG acquisition, we have made and expect to continue to make selective acquisitions. The evaluation of potential acquisitions is based on various factors, including specialized know-how, reputation, geographic coverage, competitive position and service offerings of the target businesses, as well as our experience and judgment.

Our acquisition strategy is focused on acquiring the expertise of an assembled workforce in order to continue to build upon the core capabilities of our various strategic business platforms and agency brands through the expansion of their geographic reach or their service capabilities to better serve our clients. Additional key factors we consider include the competitive position and specialized know-how of the acquisition targets. Accordingly, as is typical in most service businesses, a substantial portion of the assets we acquire are intangible assets, primarily consisting of the know-how of the personnel, which is treated as part of goodwill and is not required to be valued separately under U.S. GAAP. For each acquisition, we undertake a detailed review to identify other intangible assets that are required to be valued separately. A significant portion of the identifiable intangible assets acquired is derived from customer relationships, including the related customer contracts, as well as trade names. In valuing these identified intangible assets, we typically use an income approach and consider comparable market participant measurements.

We evaluate goodwill for impairment annually at May 1 each year and whenever events or circumstances indicate the carrying value may not be recoverable. Under the Financial Accounting Standards Board's ("FASB") ASC Topic 350, Intangibles - Goodwill and Other, we have the option of either assessing qualitative factors to determine whether it is more-likely-than-not that the carrying value of our reporting units exceeds their respective fair value (Step 0) or proceeding directly to the quantitative goodwill impairment test. While there were no trigger events that required us to perform a quantitative test, we performed the annual quantitative impairment test and compared the fair value of each of our reporting units to its respective carrying value, including goodwill. Beginning in December of 2025, we integrated the newly acquired IPG businesses into our existing networks. We identified our regional reporting units as components of our operating segments, which are our four global agency networks. The regional reporting units and connected capabilities monitor performance and are responsible for the agencies in their region. They report to the segment managers and facilitate the administrative and logistical requirements of our key client matrix organization structure for delivering services to clients in their regions. We have concluded that for each of our operating segments, their regional reporting units have similar economic characteristics and should be aggregated for purposes of testing goodwill for impairment at the operating segment level. Our conclusion was based on a detailed analysis of the aggregation criteria set forth in FASB ASC Topic 280, Segment Reporting, and in FASB ASC Topic 350. Consistent with our fundamental business strategy, the agencies within our regional reporting units serve similar clients in similar industries, and in many cases the same clients. In addition, the agencies within our regional reporting units have similar economic characteristics, and the employees share similar skill sets. The main economic components of each agency are employee compensation and related costs, and direct service costs and occupancy and other costs, which include rent and occupancy costs, technology costs that are generally limited to personal computers, servers and off-the-shelf software and other overhead expenses. Finally, the expected benefits of our acquisitions are typically shared by multiple agencies in various regions as they work together to integrate the acquired agency into our virtual client network strategy.

Goodwill Impairment Review - Estimates and Assumptions

We use the following valuation methodologies to determine the fair value of our reporting units: (1) the income approach, which utilizes discounted expected future cash flows, (2) comparative market participant multiples for EBITDA (earnings before interest, taxes, depreciation and amortization) and, (3) when available, consideration of recent and similar acquisition transactions.

In applying the income approach, we use estimates to derive the discounted expected cash flows ("DCF") for each reporting unit that serves as the basis of our valuation. These estimates and assumptions include revenue growth and operating margin, EBITDA, tax rates, capital expenditures, weighted average cost of capital and related discount rates and expected long-term cash flow growth rates. All of these estimates and assumptions are affected by conditions specific to our businesses, economic conditions related to the industry we operate in, as well as conditions in the global economy. The assumptions that have the most significant effect on our valuations derived using a DCF methodology are: (1) the expected long-term growth rate of our reporting units' cash flows and (2) the weighted average cost of capital ("WACC") for each reporting unit.

The long-term growth rate and WACC assumptions used in our evaluations:

Long-term growth rate represents our estimate of the long-term growth rate for our industry and the geographic markets we operate in. For the past 10 years, the average historical revenue growth rate of our reporting units and the Average Nominal GDP, or NGDP, growth of the countries comprising the major markets that account for substantially all of our revenue was approximately 3.5% and 5.0%, respectively. We considered this history when determining the long-term growth rates used in our annual impairment test at May 1, 2026. Included in the 10-year history is the full year 2020 that reflected the negative impact of the COVID-19 pandemic on the global economy and our revenue. We believe marketing expenditures over the long term have a high correlation to NGDP, notwithstanding the volatility of inflationary environments. Based on our past performance, we also believe that our growth rate can exceed NGDP growth in the short-term in the markets we operate in, which are similar across our reporting units. Accordingly, for our annual test as of May 1, 2026, we used an estimated long-term growth rate of 3.5%.

When performing the annual impairment test as of May 1, 2026 and estimating the future cash flows of our reporting units, we considered the current macroeconomic environment, as well as industry and market specific conditions in 2026. There were no events through September 30, 2026 that would change our impairment assessments.

The WACC is comprised of: (1) a risk-free rate of return, (2) a business risk index ascribed to us and to companies in our industry comparable to our reporting units based on a market derived variable that measures the volatility of the share price of equity securities relative to the volatility of the overall equity market, (3) an equity risk premium that is based on the rate of return on equity of publicly traded companies with business characteristics comparable to our reporting units, and (4) a current after-tax market rate of return on debt of companies with business characteristics similar to our reporting units, each weighted by the relative market value percentages of our equity and debt.

Our four reporting units vary in size with respect to revenue and the amount of debt allocated to them. These differences drive variations in fair value among our reporting units. In addition, these differences as well as differences in book value, including goodwill, cause variations in the amount by which fair value exceeds book value among the reporting units. The goodwill balances and debt vary by reporting unit primarily because some legacy agency networks were acquired at the formation of Omnicom and were accounted for as a pooling of interests that did not result in any additional debt or goodwill being recorded. The remaining agency networks were built through a combination of internal growth and acquisitions that were accounted for using the acquisition method and as a result, they have a relatively higher amount of goodwill and debt. Finally, the allocation of goodwill when components are transferred between reporting units is based on relative fair value at the time of transfer.

Goodwill Impairment Review - Conclusion

Based on the results of our impairment test, we concluded that our goodwill as of May 1, 2026 was not impaired, because the fair value of each of our reporting units was in excess of its respective net book value. The minimum decline in fair value that one of our reporting units would need to experience in order to fail the goodwill impairment test was approximately 37%. Notwithstanding our belief that the assumptions we used for WACC and long-term growth rate in our impairment testing were reasonable, we performed a sensitivity analysis for each reporting unit. The results of this sensitivity analysis on our impairment test as of May 1, 2026 revealed that if the WACC increased by 1% and/or the long-term growth rate decreased by 1%, the fair value of each of our reporting units would continue to be in excess of its respective net book value and would pass the impairment test.

We will continue to perform our impairment test at May 1 each year, unless events or circumstances trigger the need for an interim impairment test. The estimates used in our goodwill impairment test do not constitute forecasts or projections of future results of operations, but rather are estimates and assumptions based on historical results and assessments of macroeconomic factors affecting our reporting units as of the valuation date. We believe that our estimates and assumptions are reasonable, but they are subject to change from period to period. Actual results of operations and other factors will likely differ from the estimates used in our discounted cash flow valuation, and it is possible that differences could be significant. A change in the estimates we use could result in a decline in the estimated fair value of one or more of our reporting units from the amounts derived as of our latest valuation and could cause us to fail our goodwill impairment test if the estimated fair value for the reporting unit is less than the carrying value of the net assets of the reporting unit, including its goodwill. A large decline in estimated fair value of a reporting unit could result in a non-cash impairment charge and may have an adverse effect on our results of operations and financial condition.