Customs is a foreign trade instrument that has existed for ages and it can be defined as a tax levied on imports, exports or transit through the territory of a country. Customs duties belong to a group of indirect taxes. The Customs Administration is structured as follows: Central Office Sectors, Regional Customs Offices, Customs Offices and Border Customs Offices. The Dubrovnik Customs Statute represents one of the oldest original customs books in Europe, "Liber Statutorum Doane". On October 8, 1991, Croatia became an independent state and the customs system had also become autonomous after the first president, Franjo Tuđman, passed a regulation entitled „The Decree Proclaiming the Customs Law“. Since then, Croatia has joined the World Customs Organisation (WCO) and the World Trade Organisation (WTO). Customs duties are imposed in order to control international trade, protect domestic production, equilibrate the balance of payments and the needs of the state budget. The fundamental resources of the customs law are: the Law on the Implementation of Customs Control of the EU Legislation, the Customs Tariff Act and the Customs Service Act. With the accession of the Republic of Croatia to the European Union, the borders with other EU member states will be abolished and fees shall be prohibited between Member States or between countries with which the Union has free trade agreements. In conclusion, all 28 European Union countries act collectively as one customs authority. Goods that are imported into their national territory from the rest of the world are subject to the same tariffs, but are not subject to tariffs in domestic trade.