International cooperation in tax administration Abstract This diploma thesis is about international cooperation in tax administration. Due to the globalization process which makes it possible for taxpayers to run economic activities from around the world became the topic of international cooperation in tax administration a very topical issue. Although we can date the beginning of this cooperation to middle ages, the biggest steps forward were made in the last decades. Main players on the field of administrative cooperation regarding taxes are besides individual states international, intergovernmental institutions such as OECD, UN and naturally European Union. All of these players release legal texts which regulate international cooperation in tax administration. Most relevant legal regulations on the international level are bilateral Double Tax Treaties which set the foundation of international cooperation in between states. Another important document is multilateral Convention on Mutual Administrative Assistance in Tax Matters with 146 participating jurisdictions. Last documents that are impossible to omit are the OECDs and UNs Model Double Taxation Conventions which are well used by states when negotiating the contents of already mentioned Double Tax Treaties. The main European Union's legal regulation...