Taxpayers often need advisory services for foreign tax questions. However, the tax recognition of these foreign tax advisory costs in the country of residence is often limited and diverges from country to country. Within the European Union, it is questionable as to how far the recognition of similar situations should diverge between different member states. Based on this deliberation, the contrary treatment of foreign tax advisory costs under German and Austrian tax law represents an intra-European inconsistency. To avoid the inconsistent treatment of a profession’s services and to enhance the freedom of establishment within the European Union, Alexander Moßhammer demonstrates which aspects of national tax laws should be harmonized.