The purpose of this chapter is to examine the role of the European Union in the regulation of B2B practices in transnational supply chains. The transformation of the economy into global value chains has set in motion a series of changes that are radically transforming the substance and institutional framework of traditional private laws, which struggle to ensure the participation of local SMEs in crossborder supply chains. This transformation has been accompanied by the emergence of a set of innovative regulatory mechanisms aimed at increasing the ‘inclusiveness’ of supply chains, such as standard form contracts, supply chain-wide codes of conduct and private labels for ‘fair trading’. From the enforcement perspective, the traditional role of courts in the fight against abusive trading practices gives way to the increasing use of mediation mechanisms, certification regimes and collective contracts in dedicated supply chains. The resulting map of enforcement showcases an intricate network of public and private actors in which professional and trading associations emerge as the key power players of chain governance. Against that background, this chapter compares the evolution of enforcement activities across France, Spain and the United Kingdom, whose experience provides a benchmark for assessing EU strategy in the face of transnational supply chains.