Timeline and Key Documents

 Click or tap on the links below to go to:

  • The Timeline - key events following the referendum on EU membership.
  • Future Dates - View the important upcoming dates relating to EU Exit, including the Assembly’s democratic consent vote on the Protocol on Ireland/Northern Ireland.



The Timeline

This is a timeline outlining the key events following the referendum on EU membership. It also provides links to key documents and legislation relating to the negotiations and EU Exit.


  • 23 June 2016 - Referendum

    The UK votes in a referendum to leave the EU by 52% to 48%.

  • 29 March 2017 - Article 50

    Then UK Prime Minister Theresa May triggers Article 50, the legal mechanism for a Member State to leave the EU.

  • 19 June 2017 - Negotiations begin

    Negotiations begin between the UK Government and Michel Barnier, on behalf of the EU.

  • 9 December 2017 - Joint Report

    The UK and EU release a Joint Report on their agreement in principle on citizens’ rights, the unique circumstances in Northern Ireland, and the financial settlement.

  • 26 June 2018 - EU Withdrawal Bill

    The European Union (Withdrawal) Bill 2018 receives Royal Assent.

  • 21 June 2019 - North South Cooperatation

    Publication of the mapping exercise on North – South cooperation carried out during Phase 1 of the negotiations by the UK and EU.

  • 17 October 2019 - Withdrawal Agreement and Political Declaration

    Agreement is reached between the negotiators on the Withdrawal Agreement, including the Protocol on Ireland/Northern Ireland and Political Declaration.

  • 11 January 2020 - Assembly Restored

    The Northern Ireland Assembly is restored with the ‘New Decade, New Approach’ agreement.

  • 23 January - Withdrawal Bill receives Royal Assent

    The European Union (Withdrawal Agreement) Bill 2020 receives Royal Assent.

  • 24 January 2020 - Withdrawal Agreement signed

    The Withdrawal Agreement is signed by the EU and UK.

  • 31 January 2020 - UK leaves the EU

    The United Kingdom officially leaves the European Union at 11pm.

  • 1 February 2020 - Transition period begins

    The Withdrawal Agreement enters into force and the UK enters the transition period.

  • 2 March 2020 - Negotiations on Future Relationship

    Negotiations on the Future Relationship formally begin.

  • 30 March 2020 - First meeting of Joint Committee

    The first meeting of the Withdrawal Agreement Joint Committee is held. The Committee oversees the implementation of the Withdrawal Agreement and Protocol on Ireland/Northern Ireland.

  • 1 December 2020 - Joint Committee adopts decisions on the Protocol

    The Joint Committee adopts decisions providing clarity on outstanding issues relating to the Protocol.

  • 24 December 2020 - EU and UK reach a deal

    EU and UK negotiators reach a deal on a future relationship.

  • 30 December 2020 - Future Relationship Bill receives Royal Assent

    The European Union (Future Relationship) Bill 2020 receives Royal Assent.

  • 1 January 2021 - EU-UK Trade Agreement

    The transition period ends and the EU-UK Trade and Cooperation Agreement provisionally enters into force.

  • 3 March 2021 - UK extends grace periods

    UK unilaterally takes ‘temporary technical steps’ to extend until 1 October grace periods relating to the Protocol on Ireland/Northern Ireland.

  • 15 March 2021 - EU Legal Action

    Following the UK’s unilateral move, the EU launches legal proceedings against the UK.

  • 27 April 2021 - European Parliament ratifies deal

    The European Parliament ratifies the EU-UK Trade and Cooperation Agreement, passing an accompanying resolution.

  • 21 July 2021 - UK Command Paper

    The UK Government publishes a Command Paper on its proposed approach to the Protocol.

  • 6 September 2021 - Grace periods extended

    The UK Government announced it will continue to operate the Protocol on the current basis, including the grace periods currently in force.

  • 13 October 2021 - Commission proposals

    The European Commission publishes proposals on engagement with Northern Ireland stakeholders and authorities,  customs, Sanitary and Phytosanitary (SPS) issues and medicines. The UK and EU then entered intense negotiations on the Protocol.

  • 17 December 2021 - Medicines supply under the Protocol

    The European Commission puts forward proposals to ensure the continued long-term supply of medicines from Great Britain to Northern Ireland.

  • April 2022 - Medicines supply under the Protocol

    The European Parliament and the EU Council approved changes to EU law which aim to guarantee the continued supply of medicines to Northern Ireland.

  • 12-13 May 2022 - EU-UK Parliamentary Partnership Assembly (PPA)

    The first meeting of the EU-UK Parliamentary Partnership Assembly (PPA) took place in Brussels.

  • 13 June 2022 - Northern Ireland Protocol Bill

    UK Government published the Northern Ireland Protocol Bill, which would disapply core parts of the Protocol relating to trade in goods, subsidy control, the role of the Court of Justice of the EU, plus allow changes to VAT.

  • 15 June 2022 - EU Responds with legal action

    The EU launched infringement proceedings against the UK “for breaking international law”. It also published additional details on its solutions of October 2021 to ease movement of goods between GB and NI (EU position papers on customs and sanitary and phytosanitary issues).

  • July 2022 - UK legislation and EU legal action

    The Northern Ireland Protocol Bill completed its stages in the House of Commons and proceeds unamended to the House of Lords. The European Commission launched four new infringement procedures against the UK for not properly implementing the Protocol.

  • 22 September 2022 - Retained EU Law Bill

    The Retained EU Law Bill was introduced to Parliament.

  • 4 October 2022 - Civil Society Forum

    The first meeting of the Civil Society Forum was held in Brussels.



Future Dates

Important upcoming dates relating to EU Exit, including the introduction of checks and controls, and the Assembly’s democratic consent vote on the Protocol on Ireland/Northern Ireland.

31 December 2023 UK to introduce its new regime for border import controls.
31 December 2023 Under the Retained EU Law Bill, the majority of retained EU law would expire, unless preserved.
31 December 2024 By this date, the first vote will take place in the Northern Ireland Assembly on the continued application of Articles 5-10 of the Protocol on Ireland/Northern Ireland, as outlined in the democratic consent mechanism. Read our explainer on the consent mechanism.
31 December 2024 Businesses need to start using the UK's new product safety marking - UKCA Conformity Assessed (UKCA). Under the Protocol, the CE marking will continue to be recognised for goods sold in Northern Ireland.
31 December 2025 First review of the EU-UK Trade and Cooperation Agreement, to take place every five years.
30 June 2026 Adjustment period for fishing ends, annual negotiations on access to fishing waters begin.

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