The European Union (EU) is a political and economic union of 27 member states that are party to the EU's founding treaties, and thereby subject to the privileges and obligations of membership. They have agreed by the treaties to share their own sovereignty through the institutions of the European Union in certain aspects of government. State governments must agree unanimously in the Council for the union to adopt some policies; for others, collective decisions are made by qualified majority voting. These obligations and sharing of sovereignty within the EU (sometimes referred to as supranational) make it unique among international organisations, as it has established its own legal order which by the provisions of the founding treaties is both legally binding and supreme on all the member states (after a landmark ruling of the ECJ in 1964). A founding principle of the union is subsidiarity, meaning that decisions are taken collectively if and only if they cannot realistically be taken individually.
Each member country appoints to the European Commission a European Commissioner. The commissioners do not represent their member state but work collectively in the interests of all the member states.
In the 1950s, six core states founded the EU's predecessor European Communities (Belgium, France, Italy, Luxembourg, the Netherlands, and West Germany). The remaining states have acceded in subsequent enlargements. To accede, a state must fulfil the economic and political requirements known as the Copenhagen criteria, which require a candidate to have a democratic government and free-market economy together with the corresponding freedoms and institutions, and respect for the rule of law. Enlargement of the Union is also contingent upon the consent of all existing members and the candidate's adoption of the existing body of EU law, known as the acquis communautaire.
The United Kingdom, which had acceded to the EU's predecessor in 1973, ceased to be an EU member state on 31 January 2020, in a political process known as Brexit. No other member state has withdrawn from the EU and none has been suspended, although some dependent territories or semi-autonomous areas have left.
List
Notes
Former member states
Outermost regions
There are a number of overseas member state territories which are legally part of the EU, but have certain exemptions based on their remoteness; see Overseas Countries and Territories Association. These "outermost regions" have partial application of EU law and in some cases are outside of Schengen or the EU VAT area—however they are legally within the EU. They all use the euro as their currency.
Abbreviations
Abbreviations have been used as a shorthand way of grouping countries by their date of accession. EU15 includes the fifteen countries in the European Union from 1 January 1995 to 1 May 2004. The EU15 comprised Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain, Sweden, and United Kingdom. Eurostat still uses this expression. EU19 includes the countries in the EU15 as well as the Central European member countries of the OECD: Czech Republic, Hungary, Poland, and Slovak Republic. EU11 is used to refer to the Central, Southeastern Europe and Baltic European member states that joined in 2004, 2007 and 2013: in 2004 the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, the Slovak Republic, and Slovenia; in 2007 Bulgaria, Romania; and in 2013 Croatia. EU27 means all the member states. It was originally used in this sense from 2007 until Croatia's accession in 2013, and during the Brexit negotiations from 2017 until the United Kingdom's withdrawal on 31 January 2020 it came to mean all members except the UK. EU28 meant all the member states from the accession of Croatia in 2013 to the withdrawal of the United Kingdom in 2020.
Additionally, other abbreviations have been used to refer to countries which had limited access to the EU labour market.
A8 is eight of the ten countries that joined the EU in 2004, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, the Slovak Republic, and Slovenia. A2 is the countries that joined the EU in 2007, Bulgaria and Romania.