Mutual recognition is a cornerstone of European integration. Famously associated with the Court of Justice’s ruling in Cassis de Dijon, it has expanded beyond the free movement of goods into fields such as criminal justice, services, and risk regulation, enabling regulatory diversity. While often characterised as a general principle of Union law, this account has been questioned in the literature. This contribution reframes mutual recognition not as a free-standing legal principle guiding legal reasoning, but as a judicially developed mode of governance arising from the application of Union rules and principles. The paper traces mutual recognition’s judicial development in the case law of the Court of Justice, and then examines its advancement by the Union’s political institutions and its operationalisation in secondary legislation, with services law as a key case study. The article next links these judicial and legislative strands through their shared doctrinal foundations. Finally, it develops a governance-based account, drawing on political science and EU governance literature, to reconceptualise mutual recognition as a mechanism through which law structures and coordinates public power across the Union.