On 23 October 2019, the European Parliament and the Council adopted the Whistle-blower Directive. This article raises a fundamental question: does the Whistle-blower Directive respect taxpayers’ rights? In order to answer this question, the article first deals with two other preliminary issues. Firstly, it is asked whether the European Union has the competence to introduce whistle-blower protection, especially with regard to tax matters. Secondly, the article expounds on the impact of the Whistle-blower Directive on tax matters.