Private regulatory programs, such as certification schemes, seek to control market access by providing greater certainty about products’ credence attributes, including sustainability features of production processes. This article contributes to the literature that assesses the verification processes that determine whether private rules are being followed sufficiently by applicant rule‐targets (usually companies), and the regulatory intermediaries (auditors, assessors) that perform verification functions. By examining variation in the duration of verification processes of applicant rule‐targets, we question the assumption that within the context of a given program’s design the efficiency of the verification process is invariant across time and space. We argue that the verification process can impose hurdles that are independent of rule‐targets’ sustainability and their adherence to a private program’s rules. Our analysis of 312 fisheries seeking Marine Stewardship Council certification shows that variation among intermediaries and objections to their certification decisions explain differences in the time it takes fisheries to receive market access.