The customs sector has been neglected by analysis of Europe’s Area of Freedom, Security and Justice. However, customs have constituted one of the many instruments mobilized by national governments and Community bodies in order to build this space. This article examines how the customs sector has been instrumentalized since the 1960s. It highlights how, during a period of recomposition of European internal security, the sector has repositioned itself since the 1990s between dependence on the police and preservation of its own autonomy.