The EU-Turkey customs union is a trade agreement between the European Union (EU) and Turkey. The agreement came into force on 31 December 1995 following the decision of the European Community-Turkey Association Council of 6 March 1995 to establish a customs union (turkish language: Gomr-k Birlii) between the two parties.  Goods can move without customs restrictions between the two units. The customs union does not cover key economic sectors such as agriculture (which enforces bilateral trade concessions), services or public procurement. Thirdly, the EU should send a clear message to Turkey that it is ready to deepen the existing trade agreement only if certain conditions are met. Turkey should tackle and repair the growing number of trade irritations in recent years under the current agreement. This situation has been reported without exception by all the countries that participated in the joint research. Ankara should also honour its commitments to cooperate with Europe on migration management. Thirdly, Turkey should once again establish itself as a reliable partner for European security. This is only possible if the interest in multilateralism and diplomacy is sincere. Ankara should put an end to military threats in the eastern Mediterranean and act in the common interest of the transatlantic alliance.
However, there are also some problems arising from the implementation of the customs union. The main difficulties can be summed up as follows: the risks of trade diversion and unfair competition resulting from the reluctance of some countries to partner in the EU Free Trade Agreement (FTA) to conclude similar agreements with Turkey, giving the EU the advantage of joining the Turkish market, the lack of adequate participation in EU decision-making mechanisms in the relevant areas of the customs union, as well as technical obstacles related to road quotas imposed by some EU Member States and taking into account visas for Turkish businessmen and truck drivers. In December 2016, the European Commission published an assessment proposing to update and modernise the agreement, which includes services and public procurement.  The report ends with two options; Improved trade framework (ECF) or comprehensive free trade agreement (ACFTA).  Starting in 2020, the Council has not yet adapted the proposal. Since 2015, the Turkish government has held several meetings to assess the update of the agreement.  On the other hand, thanks to decision 1/2000 of the CE-Turkey Customs Cooperation Committee of 25.07.2000 (JO L 255 of 16.12.2000, p. 1). The customs union allows goods that meet the conditions of free movement within the customs union, but are negotiated between the EC and Turkey through other countries in the pan-European system of accumulation, provided that evidence of Community or Turkish origin is provided in one of the countries concerned. Turkey is a member of the Euro-Mediterranean Partnership (Euromed) and should therefore conclude free trade agreements with all other Mediterranean partners in order to create a Euro-Mediterranean free trade area.
Turkey has largely aligned itself with EU customs legislation. Thus, harmonization has been achieved in the following areas, which require joint implementation for the proper functioning of the customs union: origin, customs value, customs admission, customs declaration, free movement of persons, customs regimes with economic consequences, trade in goods, debt/obligation and opposition rights. Since 1996, when the customs union came into force, Turkey has reached an advanced level of reconciliation of customs legislation in this area, following efforts to bring together Turkey. The EU and Turkey meet regularly to discuss issues and best practices in implementing the agreement.