Due to transparency efforts on the part of voluntary market stakeholders’ self-regulatory bodies, identifying the entities responsible for retiring carbon credits has become more feasible – at least for those in the four major voluntary market registries over the past five years. Our analysis of entities that retire credits finds that fossil fuel companies have collectively retired the largest volume of credits since 2004, the vast majority of which come from forestry and land use projects. Firms based in Europe account for the highest share of mitigation units taken off the market overall, with large proportions of them coming from projects based in the Asia Pacific region. Fossil fuel conglomerate Shell tops the list of biggest individual carbon credit “retirer,” followed US-based Delta Air Lines, Italian energy firm Eni, German automotive manufacturer Volkswagen, and Japanese Takeda Pharmaceutical.