European Union law must be interpreted as requiring that a taxable person who has overpaid value added tax which was collected by the Member State contrary to the requirements of European Union legislation on value added tax has a right to reimbursement of the tax collected in breach of European Union law and to the payment of interest on the amount of the latter. It is for national law to determine, in compliance with the principles of effectiveness and equivalence, whether the principal sum must bear ‘simple interest’, ‘compound interest’ or another type of interest (Case C‑591/10).