Our paper provides a comprehensive report of empirical research on tax compliance costs. Comparedto previous reviews, our focus is on average costs for sub-groups (individual taxpayers, small business-es, large businesses) and the composition of the cost burden with regards to different cost components(in-house time effort, external adviser costs, other monetary expenses), different taxes (e.g. income tax,value added tax) and different activities like tax accounting and tax planning. In addition, we give ashort review of the most important compliance cost drivers and discuss the underlying causes of taxcomplexity and compliance costs.