We examine the impact of mandatory private country-by-country reporting (CbCR)—a widely adopted tax transparency initiative—on mergers and acquisitions (M&As). Using difference-in-differences and regression discontinuity designs, we document a decrease in takeover premiums for affected targets in the post-CbCR adoption period relative to unaffected targets. The decrease in premiums is more pronounced for tax-aggressive targets, suggesting that acquirers price in the increased tax enforcement risk associated with these targets. More importantly, consistent with CbCR providing incremental information to acquirers and reducing information friction during the negotiation and due diligence process, we find a higher percentage of consideration paid in cash, shorter due diligence, and better post-acquisition performance for targets subject to CbCR. Our findings highlight the role of CbCR in reducing information frictions in M&As, indicating a spillover effect of mandatory private tax disclosure for a specific group of investors—M&A acquirers—beyond tax authorities.