This article addresses the impacts of the carding system (green, yellow, red) of the European Union (EU) Regulation on illegal, unreported and unregulated (IUU) fishing on the fisheries laws of third countries. Specifically, it analyzes Thailand's national legal reforms, which followed interactions between the EU and Thailand during the yellow card period. Building on past research on the EU's use of market power to exert regulatory influence on third countries, the article explores other factors that might encourage third countries to engage in national regulatory reforms: the EU's powers of expertise, monitoring, and agenda-setting. Finally, the article also considers the legitimacy of the EU's regulatory power over third countries.