In many recent judgments the European Court of Justice (ECJ) has tested the withholding tax regimes of Member States against the fundamental freedoms. In this book, the first systematic review of these judgments in the light of other ECJ case law and legal doctrine, the author舗s prodigious research has engendered a remarkably complete answer to the question of the extent to which EU Member States are allowed to levy withholding taxes, particularly on payments to non-residents. The book shows how the fundamental freedoms interfere with national tax laws舗 withholding tax regimes, and suggests informed and insightful answers to questions not yet clarified by the ECJ. The scope of treatment goes beyond the TFEU to the EEA Agreement, various agreements with Switzerland, and a number of association and partnership agreements with third countries.