International trade is increasingly regulated through standardization, certification, and accreditation. To ensure that consumers can trust that the products they buy meet regulators’ standards, third-party certifiers and accreditation bodies, which “certify the certifiers,” act as intermediaries enlisted to deliver conformity assessment certificates to producers. This article explores how a few third-party certifiers have exploited their position between multiple regulators and diverse targets to invest in a growing number of sectors, expand globally, and become preferred advisers to regulators. As regulators enlist them to standardize certification practices, big third-party certifiers (BTPCs) advise regulators to set system-based regulations that are better suited to their own organizations and networks of international subsidiaries.