Basis of Presentation and Recent Developments	9 Months Ended
Sep. 30, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Recent Developments	1. Business and Basis of Presentation Stagwell Inc. (together with its consolidated subsidiaries, unless the context requires otherwise, the “Company,” “we,” or “Stagwell”), incorporated under the laws of Delaware, operates a global network of technology-enabled marketing & advertising, media, data, and technology businesses (“Brands”). We help clients grow by delivering both discrete and integrated products and services, including self-service software-as-a-service (“SaaS”), data-as-a-service (“DaaS”), and licenses of our proprietary software. Our offerings address needs such as creative, communications strategy, digital transformation, experiences, technology solutions, and market research across our Marketing Services, Communications, Digital Transformation, Media & Commerce, and The Marketing Cloud segments that support clients in navigating change and achieving measurable results in a rapidly evolving business environment. On September 30, 2025, the Company reorganized its organizational structure, which resulted in a realignment of its segments. Refer to Note 14 of the Notes included herein for additional information. The accompanying Unaudited Consolidated Financial Statements include the accounts of Stagwell and its subsidiaries. Stagwell has prepared the unaudited consolidated interim financial statements included herein in accordance with U.S. generally accepted accounting principles (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for reporting interim financial information on Form 10-Q. The preparation of financial statements in conformity with GAAP requires us to make judgments, assumptions and estimates about current and future results of operations and cash flows that affect the amounts reported and disclosed. Actual results could differ from these estimates and assumptions. The consolidated reports for interim periods are not necessarily indicative of results for the full year and should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2025 (the “2025 Form 10-K”). The accompanying financial statements reflect all adjustments, consisting of normal recurring accruals, which in the opinion of management are necessary for a fair statement, in all material respects, of the information contained therein. Intercompany balances and transactions have been eliminated in consolidation. Certain reclassifications have been made to the prior year financial information to conform to the current year’s presentation. During the nine months ended September 30, 2026, we recorded $8.2 million in out-of-period adjustments to correct for errors related to prior periods. The adjustments, which were identified during the second quarter of 2026, primarily related to an understatement of employer payroll tax that impacted our Cost of services and Office and general expenses financial statement line items in the Unaudited Consolidated Statements of Operations. The total impact of the adjustments to net loss in the nine months ended September 30, 2026, was $6.0 million. The Company evaluated the impact of the out-of-period adjustments and concluded that the errors were not material to the Company’s previously issued financial statements and are not expected to be material to the year ending December 31, 2026. Accounting Change In January 2026, the Company adopted Accounting Standards Update (“ASU”) 2025-05, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets. The amendments provide a practical expedient and clarifications related to estimating expected credit losses on current accounts receivable and current contract assets. The Company applied the amendments prospectively and elected the practical expedient. Adoption of ASU 2025-05 did not have a material impact on the Company’s consolidated financial statements. Recent Development On October 23, 2026, the Company acquired all of the outstanding stock of Publisher First, Inc., doing business as Freestar, which assists online publishers in monetizing the media on their sites, for $50.0 million: $30.0 million in 3,442,043 shares of Class A Common Stock, par value $0.001 per share (the “Class A Common Stock”) and $20.0 million in cash, subject to post-closing adjustments. The sellers can also earn up to $60.0 million in contingent consideration if future earnings targets are met, plus a share of earnings above those targets. The Company may settle part of the contingent consideration in stock, and payments to certain holders are subject to their continued employment. Due to the timing of the acquisition, the Company is currently evaluating the purchase price allocation, including the fair value of the consideration transferred and the assets acquired and liabilities assumed.

Stagwell Inc. (together with its consolidated subsidiaries, unless the context requires otherwise, the “Company,” “we,” or “Stagwell”), incorporated under the laws of Delaware, operates a global network of technology-enabled marketing & advertising, media, data, and technology businesses (“Brands”). We help clients grow by delivering both discrete and integrated products and services, including self-service software-as-a-service (“SaaS”), data-as-a-service (“DaaS”), and licenses of our proprietary software. Our offerings address needs such as creative, communications strategy, digital transformation, experiences, technology solutions, and market research across our Marketing Services, Communications, Digital Transformation, Media & Commerce, and The Marketing Cloud segments that support clients in navigating change and achieving measurable results in a rapidly evolving business environment.

On September 30, 2025, the Company reorganized its organizational structure, which resulted in a realignment of its segments. Refer to Note 14 of the Notes included herein for additional information.

The accompanying Unaudited Consolidated Financial Statements include the accounts of Stagwell and its subsidiaries. Stagwell has prepared the unaudited consolidated interim financial statements included herein in accordance with U.S. generally accepted accounting principles (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for reporting interim financial information on Form 10-Q. The preparation of financial statements in conformity with GAAP requires us to make judgments, assumptions and estimates about current and future results of operations and cash flows that affect the amounts reported and disclosed. Actual results could differ from these estimates and assumptions. The consolidated reports for interim periods are not necessarily indicative of results for the full year and should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2025 (the “2025 Form 10-K”).

The accompanying financial statements reflect all adjustments, consisting of normal recurring accruals, which in the opinion of management are necessary for a fair statement, in all material respects, of the information contained therein. Intercompany balances and transactions have been eliminated in consolidation. Certain reclassifications have been made to the prior year financial information to conform to the current year’s presentation.

During the nine months ended September 30, 2026, we recorded $8.2 million in out-of-period adjustments to correct for errors related to prior periods. The adjustments, which were identified during the second quarter of 2026, primarily related to an understatement of employer payroll tax that impacted our Cost of services and Office and general expenses financial statement line items in the Unaudited Consolidated Statements of Operations. The total impact of the adjustments to net loss in the nine months ended September 30, 2026, was $6.0 million. The Company evaluated the impact of the out-of-period adjustments and concluded that the errors were not material to the Company’s previously issued financial statements and are not expected to be material to the year ending December 31, 2026.

In January 2026, the Company adopted Accounting Standards Update (“ASU”) 2025-05, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets. The amendments provide a practical expedient and clarifications related to estimating expected credit losses on current accounts receivable and current contract assets. The Company applied the amendments prospectively and elected the practical expedient. Adoption of ASU 2025-05 did not have a material impact on the Company’s consolidated financial statements.

On October 23, 2026, the Company acquired all of the outstanding stock of Publisher First, Inc., doing business as Freestar, which assists online publishers in monetizing the media on their sites, for $50.0 million: $30.0 million in 3,442,043 shares of Class A Common Stock, par value $0.001 per share (the “Class A Common Stock”) and $20.0 million in cash, subject to post-closing adjustments. The sellers can also earn up to $60.0 million in contingent consideration if future earnings targets are met, plus a share of earnings above those targets. The Company may settle part of the contingent consideration in stock, and payments to certain holders are subject to their continued employment. Due to the timing of the acquisition, the Company is currently evaluating the purchase price allocation, including the fair value of the consideration transferred and the assets acquired and liabilities assumed.