The procedure for withdrawal from the European Union is regulated by Article 50 TEU which provides possibility of voluntary withdrawal of a Member State from the EU. The first time this article was activated was during the withdrawal process of the United Kingdom. Since the article had not been activated until then, certain challenges emerged in its application in practice. The Union institutions, and in particular the Court of Justice, have played a significant role in overcoming these challenges. The withdrawal procedure under the Article 50 TEU includes: notification to the European Council of the intention to withdraw, then negotiation and conclusion of an angreement which establishes withdrawal arrangements and finally withdrawing stricto sensu on the date of entry into force of the agreement or if it is not reached, after two years from notification, if that period is not extended. Therefore, the withdrawing Member State has the possibility to negotiate and conclude the withdrawal agreement with the Union or to withdraw upon expiry of the 2-year term (unless extended) if there was no consensus on the withdrawal agreement. Art. 50. TEU also provides the possibility for a State which has withdrawn from the Union to rejoin in accordance with Art. 49. TEU.