The taxation of revenues from cross-border leasing transactions is not conclusively regulated within the European VAT system. Binding criteria for when the provisions regarding supplies or services should be applied are neither derived from the VAT Directive nor from the case law of the European Court of Justice. The application of the economic approach can lead to different qualifications of leasing transactions. In certain cases, this results in double taxation or double non-taxation of cross-border leasing revenues. Both scenarios represent a disruption in the harmonized VAT system. The work discusses comparative legal causes and potential solutions. It is aimed at tax law scholars, business lawyers, and European law experts. The work was awarded the Maurice Lauré Prize 2011 by the IFA.