The question „Is there a permanent establishment?“ (PE) is one of the most frequent tax treaty issues that enterprises, their advisors, government officials, and courts have to deal with. At an international level, guidance to answer this question can be found in the Commentary on the OECD Model Tax Convention and, to a lesser extent, on the UN Model Tax Convention. Substantial differences, however, can be found in defining the term as used in Art. 5 of the OECD Model Tax Convention which may result in double taxation. That is why the International Fiscal Association (IFA) has decided to choose this topic as one of the two main subjects to be discussed at the IFA Congress 2009. According to the guidelines given by the general reporters, the Branch Reports should focus on the judicial and administrative guidance available in the jurisdiction covered by the Reports to interpret the tax treaty definition of the term „permanent establishment“. The aim should be to contribute to a more uniform interpretation of the definition or at least to identify those aspects where there is difference among jurisdictions and where further guidance is needed at an international level. Stefan Bendling...