The customs union is the essential element of the internal market. Its introduction was the primary objective after the signature of the Treaty of Rome and continued until 1968. The most important measures included:
- the elimination of all customs duties and restrictions among the Member States;
- the introduction of a common customs tariff (CCT), applicable throughout the European Community to third country goods (the income obtained as a result forming part of the Community's own resources);
- the common commercial policy as an external dimension of the customs union (the Community speaks with one voice at international level).
Common procedures and rules were drawn up together with a Single Administrative Document (SAD) aimed at replacing the different documents previously used. With the entry into force of the single market in 1993, all routine checks at internal borders were abolished, as were customs formalities. Thus, the customs services of the Member States lost their responsibility for collecting excise duties, VAT and statistical data.
The Community has concluded special agreements to facilitate trade, for example the agreement with the European Economic Area (EEA), and to encourage development by providing preferential access to European markets, for example the Lomé Convention, signed with the African, Caribbean and Pacific countries (ACP).
Future challenges include promoting closer cooperation between the national administrations and combating fraud through the successive Customs 2002 and Customs 2007 programmes. A particular focus of Customs 2007 will be helping new Member States adapt their systems to open market conditions and implement customs controls at the new external borders of the European Union.