For at least three decades, the EU and its Member States have engaged in a process of “externalisation” – a policy agenda by which the EU seeks to prevent migrants and refugees setting foot on EU territory by externalising (that is, outsourcing) border controls to non-EU states. This report aims to contribute to public and political debate on the transparency, accountability and legitimacy of the externalisation agenda, based on case studies on three key target states for the EU – Bosnia and Herzegovina, Morocco and Niger.