Turkey joined a union.
The European Union Customs Union ( EUCU ) is a customs union which consists of all the member states of the European Union ( EU ) , Monaco , and some territories of the United Kingdom which are not part of the EU ( Akrotiri and Dhekelia , Bailiwick of Guernsey , Bailiwick of Jersey , and the Isle of Man ) . Turkey . After becoming one of the first members of the Council of Europe in 1949 , Turkey became an associate member of the EEC in 1963 , joined the EU Customs Union in 1995 and started accession negotiations with the European Union in 2005 .