ARCHIVED: This archived Practice Note provides information on the impact of IP completion day for tax. It reflects the position immediately following the IP completion day on 31 December 2020. It is not maintained and is for background information only. For more information, see: Brexit, assimilated law and tax—overview.

As of exit day (11 pm on 31 January 2020), the UK ceased to be an EU Member State and no longer participates in the political institutions and governance structures of the EU. In accordance with the transitional arrangements provided in Part 4 of the Withdrawal Agreement, exit day marked the commencement of an 11-month implementation period during which the UK continued to be treated by the EU as a Member State for many purposes.

The implementation period ran from exit day until IP completion day (11 pm on 31 December 2020). During this period, the UK continued to adhere to its obligations under EU law (including EU treaties, legislation, principles and international agreements), and submitted to the continuing jurisdiction of the Court of Justice