The External Tax Treaty Making Powers of the Member States: Defining Limits and Obligations under the Current European Legal Order

The article analyses the external treaty making powers of the EU and its Member States in the direct tax area and its main purpose is to describe the limits and obligations imposed on the external action of Member States by EU law in such field. Starting from a comprehensive analysis of the external competences of the EU, the article discusses the existence and nature of EU competence in direct taxation matters, giving special attention to the application of the implied powers doctrine. The article, then, focuses on the importance of the general duty of loyalty as a restraint on the external actions of Member States in the direct tax arena and presents suggestions on how to reach a balance between the rights and obligations of Member States in tax treaty negotiations with third countries.