Purpose: To analyze the effects of audit tenure and audit opinion on audit report lag at private sector trading companies served by XYZ Public Accounting Firm, and to analyze the role of Financial Accounting Standards (SAK) in moderating the effects of audit tenure and audit opinion on audit report lag at private sector trading companies served by XYZ Public Accounting Firm. Research Methodology: This study was conducted at XYZ Public Accounting Firm in Central Jakarta. A quantitative approach was used. Data was collected through documentation in the form of the firm’s internal records. Data analysis was performed using SPSS. Results: Based on a total sample of 30, the multiple linear regression analysis showed that the audit tenure variable (LnX1) had a regression coefficient of -0.862 and a significance value (Sig.) of <0.001, while the audit opinion variable (X2) had a regression coefficient of 0.587 and a significance value (Sig.) of 0.003. Moderation regression analysis of the interaction variable between audit tenure and financial accounting standards (LnX1_Z) yielded a regression coefficient of -0.303 and a significance value (Sig.) of 0.443, whereas the interaction variable between audit opinion and financial accounting standards (X2_Z) yielded a regression coefficient of 0.911 and a significance value (Sig.) of 0.038. Conclusions: The results of the study indicate that auditor tenure and audit opinion simultaneously influence audit report lag, both before and after moderation. Partially, auditor tenure has a negative effect on audit report lag, while audit opinion has a positive effect on audit report lag. Financial Accounting Standards (SAK) do not moderate the effect of auditor tenure on audit report lag. Financial Accounting Standards (SAK) moderate and strengthen the effect of audit opinion on audit report lag. Limitations: This study is limited to private-sector trading companies that are clients of XYZ Public Accounting Firm, with a relatively short observation period spanning from 2021-2024. Contributions: This study provides a theoretical contribution regarding the influence of an auditor’s tenure and audit opinion on minimizing delays in the submission of audit reports, as well as an understanding of the impact of audit opinions on the smoothness of the audit process