During the transition period, the UK will retain the benefits of EU membership and will remain a part of the EU’s internal market and customs union. Simultaneously it will start trade negotiations with the EU. On the other hand, the UK will lose its representation in the European institutions and will not participate in EU decision-making. The post-Brexit transition period ends at the end of 2020. The UK has stated that it will not request an extension of the transition period.

The shortest free trade agreement negotiations the EU has ever held were with South Korea and took two and a half years, with another eighteen months for approval and ratification. Most free trade agreements take six to eight years to negotiate. The FTA negotiations with Canada, often cited as a model for the UK, began in 2009 and were concluded in 2017. It will take another seven years for all aspects of the agreement to take effect.

9 August 1961: Britain formally applies to join what was then called the European Economic Community (EEC).

14 January 1963: France's president Charles de Gaulle vetoes the application. He rejects it again on 27 November 1967.

1 January 1973:  Britain finally enters the EEC at the same time as Ireland and Denmark, after De Gaulle has left office..

5 June 1975: In a referendum called by the new Labour government on remaining in the EEC, more than 67% of Britons vote "Yes".

Source: Freedom House 2019