The EU as a Catalyst for Tax Harmonisation – Triumphs and Challenges in an Asymmetric Cooperation Model

This paper critically analyses the taxation chapter in the book 70 Years of EU Law – A Union for Its Citizens (2023), edited by the Legal Service of the European Union (EU) Commission. The said chapter provides a clear explanation of how fundamental freedoms, as interpreted by the European Court of Justice (ECJ), affect internal legislation of Member States related to income taxation of individuals. Its approach aligns with the overall structure of the book, which emphasises the positive impact of EU law on the daily lives of European citizens, consistent with an output legitimacy perspective on European integration. However, its scope is markedly narrow. To supplement its insights, this paper expands on the topics in two ways. First, consistent with the focus on output legitimacy, it highlights the major achievements of EU law in areas such as consumption taxes, customs, and corporate taxation. Secondly, it discusses the underlying tensions that lead to the current asymmetrical model of EU tax law and the policy issues it raises, including the over-reliance on the Court of Justice to promote (negative) harmonisation and the challenges posed by the unanimity requirement in taxation matters.