In order to mitigate the consequences of exempting financial services from VAT, the Member States of the European Union have the power to allow financial service providers to opt for taxation. In this article, the authors provide a brief insight into the issue of determining the taxable base for financial services and they give a summary of the option systems currently applicable in six Member States, indicating their limitations, the conditions under which the options apply and the practical effects of the options. Finally, they give an overview of the essential elements of an option system.