The thesis deals with international cooperation in the fight against tax evasion in the field of direct taxation at the level of OECD and EU. First, the thesis explains why international tax evasion occurs, what the most common forms of tax evasion are and also how multinational companies use international, sometimes even aggressive, tax planning to reduce the tax burden. The next section specifies diverse measures already adopted within the OECD and the EU and also those that are still in preparation. Any action taken at the international level is put into context with what the Czech Republic has already introduced. Mutual exchange of information between countries is one of the most important tools in the fight against tax evasion. That is why an analysis of spontaneous exchange of information and on request between CZ and other cooperating countries was carried out in the last part of the thesis. The analysis was carried out on the basis of publicly available data from Annual Reports of Financial Administration of the Czech Republic and also on the basis of data which were received from the Department of international tax cooperation - direct taxes of General Financial Directorate.

Jurisdictions around the world currently compete to attract mobile capital of multinational companies by providing them the most favourable tax conditions. Some EU member states actively participate in tax competition. Over the past decade, the European Commission has successfully enacted a number of measures aimed at preventing multinational companies from implementing aggressive tax planning schemes. These measures aim to establish fair conditions for competitors on the internal market and to meet the demand of the public and of the international community for suppression of aggressive tax planning. The theoretical background of the thesis derives from the field of Law and Economics, specifically by using the concept of transaction costs and means of Economic analysis of criminality. This thesis aims to answer the question of whether the new EU legislation leaves room for the member states to continue in allowing multinational companies to optimize taxes in the ways targeted by the EU measures. The thesis consists of two case studies, which evaluate the impact of the rules on known tax optimization schemes. The first one analyses the impact of state aid proceedings on tax rulings and the second one analyses the influence of the controlled foreign company rule on harmful IP boxes. The objective...