The United Kingdom is not a member state of the European Union. Relations between the European Union (EU) and the United Kingdom of Great Britain and Northern Ireland (UK) are governed, since 1 January 2021, by the EU–UK Trade and Cooperation Agreement (TCA).
Relations trace back to the foundation of the European Communities, the European Union's predecessor, in 1957. The UK was a member state of the bloc after joining it in 1973 (which was confirmed in a referendum on membership in 1975) until it became the first country to voluntarily end its membership on 31 January 2020 after a second referendum on membership was held in 2016 which resulted in 51.9% of voters opting to leave.
