The "Prove It Act of 2025" aims to significantly increase transparency and accountability in federal regulatory decisions that affect small businesses. It amends title 5, United States Code, to strengthen requirements for agencies to thoroughly assess the economic impact of proposed rules on small entities, particularly by including reasonably foreseeable potential indirect costs in their initial regulatory flexibility analyses. These indirect costs cover impacts on small businesses that interact with directly regulated entities or are otherwise affected by a rule's ripple effects. A central provision establishes a new process allowing small entities to petition the Chief Counsel for Advocacy of the Small Business Administration to review an agency's certification that a proposed rule will not have a significant economic impact. If the Chief Counsel's full review determines the rule will have such an impact, the agency must then perform a full regulatory flexibility analysis. A significant penalty is introduced: if an agency fails to cooperate with the Chief Counsel's review, the final rule shall not apply to small entities . The legislation also requires agencies to publish all guidance documents and relevant materials for rules likely to have a significant economic impact on small entities, allowing for public comments. Furthermore, it strengthens the periodic review of existing rules by requiring agencies to consider indirect costs during their 10-year reviews. If an agency fails to conduct a required periodic review, the Chief Counsel will notify the agency that the rule has ceased to be effective , prompting the agency to publish a notification and solicit comments for reinstatement. This applies to rules issued within the last five years or after enactment.