This article aims to provide guidelines to the courts of the Member States and the CJEU concerning the authorship of external migration management deals, and the judicial review of such deals based on the general principles of EU law. The selected example of external migration management is the EU-Turkey Deal, which is identified in this article as an example of 'pseudo-authorship': the EU is the de facto author of the deal, but the Member States (as pseudo-authors) are regarded by the General Court as the actual authors. The article shows that the pseudo-authorship approach may lead to the circumvention of general principles of EU law. To avoid further erosion of these principles in the wake of any future deals on migration management, a definite need for a serious investigation of authorship exists. This article recommends assessing authorship with the three scenarios in mind that are identified in this article: the EU as only author; the EU as de facto author and the Member States as pseudo-authors; or the Member States as only authors. All three scenarios, it is argued here, induce judicial review based on the general principles of EU law.