On 21 February 2006, the Court of Justice (ECJ) delivered a series of judgments in which the doctrine of abuse of law played an important role. From those judgments, it appears that the aims and purposes of the provisions of the Sixth Directive must be taken into account for their interpretation and application. In that respect, 21 February 2006 ("Halifax Day") marked the beginning of a new stage in the evolution of the European VAT system. In this article, the author examines the background of the doctrine of abuse of law, the cases in which it was raised and, finally, its practical consequences