UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549FORM 10-K (Mark One)շANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934For the fiscal year ended December 31, 2025ORնTRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THETRANSITION PERIOD FROMTOCommission File Number 001-31666 First Advantage Corporation(Exact name of Registrant as specified in its Charter) Securities registered pursuant to Section 12(b) of the Act: Securities registered pursuant to Section 12(g) of the Act:None Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. YESշNOն Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. YESնNOշ Indicate by check mark whether the Registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. YESշNOն Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). YESշNOն Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growthcompany. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act. Large accelerated filerշNon-accelerated filerնEmerging growth companyն If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financialaccounting standards provided pursuant to Section 13(a) of the Exchange Act.ն Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financialreporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.շ If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correctionof an error to previously issued financial statements.ն Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of theregistrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).ն Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). YESնNOշ As of June 30, 2025, the aggregate market value of the registrant’s common stock held by non-affiliates of the registrant was $1,331,899,011 based on the last reported sales priceof the common stock as reported on Nasdaq. The number of shares of Common Stock outstanding as of February 20, 2026 was 174,319,117. DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s definitive Proxy Statement relating to its 2026 Annual Meeting of Stockholders to be filed with the SEC within 120 days after the end of the fiscal yearended December 31, 2025 are incorporated herein by reference in Part III. Table of Contents PART I Item 1.Business6Item 1A.Risk Factors17Item 1B.Unresolved Staff Comments37Item 1C.Cybersecurity38Item 2.Properties39Item 3.Legal Proceedings39Item 4.Mine Safety Disclosures39 PART II Item 5.Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of EquitySecurities40Item 6.[Reserved]41Item 7.Management’s Discussion and Analysis of Financial Condition and Results of Operations42Item 7A.Quantitative and Qualitative Disclosures About Market Risk63Item 8.Financial Statements and Supplementary Data64Item 9.Changes in and Disagreements With Accountants on Accounting and Financial Disclosure64Item 9A.Controls and Procedures64Item 9B.Other Information65Item 9C.Disclosure Regarding Foreign Jurisdictions that Prevent Inspections65 PART III Item 10.Directors, Executive Officers and Corporate Governance67Item 11.Executive Compensation67Item 12.Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters67Item 13.Certain Relationships and Related Transactions, and Director Independence67Item 14.Principal Accountant Fees and Services67 PART IV Item 15.Exhibits and Financial Statement Schedules68Item 16.Form 10-K Summary71 Glossary of Se