Council Directive 2006/112/EC of 28 November 2006 on the common system of VAT must be interpreted as meaning that it does not preclude the mandatory preliminary application of a national administrative procedure, such as that laid down by Article 63 of the Code of Taxation Procedure and Proceedings (Código de Procedimento e de Processo Tributário), in the event that the revenue authorities suspect the existence of an abusive practice.