Article 50 of the Treaty on European Union: What It Says

Article 50 of the Treaty on European Union (TEU) is the clause that lets a member state leave the EU. It says that a country may decide to withdraw in line with its own constitutional rules, must notify the European Council, and then negotiates an exit agreement with the Union. Unless all sides agree to extend, the treaties stop applying to that country two years after notification. The article was added by the Lisbon Treaty and, before 2017, it had never been used.

Background: a clause that did not exist before 2009

The founding treaties of the European Communities contained no exit provision. Legal commentators debated whether a state could leave at all, and by what route. Greenland ceased to be part of the European Communities in 1985 after a referendum, but it did so through a treaty amendment, since it was a territory of Denmark and not a member state in its own right.

The Lisbon Treaty, signed in 2007 and in force from 1 December 2009, wrote the first explicit procedure into the TEU. The current consolidated text is available on EUR-Lex.

The five paragraphs, one by one

The article is short. Its five paragraphs work as a sequence.

1. Decision. Any member state may decide to withdraw “in accordance with its own constitutional requirements”. The EU does not define how that decision is made; each country’s domestic law governs it.
2. Notification and negotiation. The state notifies the European Council of its intention. The Union then negotiates an agreement with it, setting out the arrangements for withdrawal and taking account of the framework for the future relationship. The agreement is concluded on behalf of the Union by the Council, acting by qualified majority, after the European Parliament consents.
3. The two-year clock. The treaties cease to apply from the date the withdrawal agreement enters into force or, failing that, two years after notification. The European Council, acting unanimously and in agreement with the state concerned, can extend that period.
4. Recusal. The departing state’s representatives do not take part in European Council or Council discussions or decisions about its own withdrawal.
5. Returning. A state that has left and later asks to rejoin is subject to the ordinary accession procedure in Article 49.

Two points the text leaves open

The wording raised questions that were settled in court and not in the treaty.

The first was who must authorise notification inside the country. In January 2017 the UK Supreme Court ruled in the Miller case that the government needed an Act of Parliament before it could give notice. That was a matter of UK constitutional law, which is exactly what paragraph 1 refers to.

The second was whether a notification, once given, could be withdrawn. In December 2018 the Court of Justice of the EU ruled in the Wightman case that a member state may revoke its notification unilaterally, provided it does so before the withdrawal agreement takes effect and before the period expires, and that the revocation is unequivocal and unconditional. The case reached the EU court on a reference from a Scottish court.

How the clause was used by the United Kingdom

The UK gave notice on 29 March 2017. The negotiated Withdrawal Agreement was concluded after several rounds of talks, and the original two-year deadline was extended more than once by agreement between the European Council and the UK. The UK left the EU on 31 January 2020, and a transition period followed. A separate trade and cooperation agreement later set the framework for the future relationship.

Those dates are matters of public record. The Brexit briefings archive on this site gives a plain-language glossary of the negotiation terms, and other pieces in the articles section cover related legal vocabulary.

What Article 50 does not cover

• It does not set the content of the exit deal. That is negotiated case by case.
• It does not describe the future trade relationship in detail. Paragraph 2 only says the negotiators must “take account” of that framework.
• It does not require a referendum. Whether to hold one is a domestic decision.
• It offers no guaranteed protection for citizens’ rights or borders. Those items had to be negotiated into the agreement.

Frequently asked questions

Has any country other than the UK used Article 50?

No other member state had triggered Article 50 at the time of writing this explainer. Check the Council or the Commission websites for any later notification, since this is a point that can change.

Can the two-year period be extended?

Yes. The European Council can extend it by unanimous decision, but only in agreement with the withdrawing state. This happened in the UK case.

Is an exit deal required?

No. If no agreement is reached, the treaties still stop applying once the period ends. The article does not guarantee any transitional arrangements.

Who votes on the deal on the EU side?

The Council decides by qualified majority after the European Parliament has given its consent. The European Council sets the guidelines for negotiation but does not itself conclude the deal.

Summary of the sequence

Decision under national law, notification, negotiation, Parliament’s consent and Council approval, then exit on the agreed date or after two years. The text is short, which is why court rulings and political practice have shaped how it is understood.