This is an Opinion Statement prepared by the ECJ Task Force of the Confédération Fiscale Européenne (CFE) on the interrelation between EU law and national procedural legislation in the area of direct taxation. The Statement focuses on the question of how taxpayers, who were forced to pay a tax on the basis of national legislation that is not in line with the EU fundamental freedoms, can realise their claim to a refund of the overpaid amount within the national legal order of the Member State concerned. The Statement discusses, in particular, the relevant provisions and principles of EU law capable of affecting the application of national procedural rules, and puts forward a concrete proposal for both the Member States and the European institutions to address this issue effectively. The CFE is the leading European association of 33 national tax advisory organisations representing over 180,000 tax advisers.