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EU enlargement

What is enlargement?

Enlargement happens when new countries join the European Union. This has taken place several times in the EU’s history, each time transforming both the EU and the countries that join.   

The enlargement of the EU has contributed significantly to the spread of stability, peace and prosperity across the continent.

Benefits for countries joining the EU

Enlargement brings many benefits for new Member States, including

  • political stability
  • freedom for citizens to live, study or work anywhere in the EU
  • increased trade via access to the single market
  • increased funding and investment
  • higher social, environmental, and consumer standards

Find out more about the benefits and achievements of the European Union.

Benefits for the EU

Enlargement also benefits the EU, as it means

  • increased prosperity and opportunities for European citizens and businesses
  • a stronger voice on the world stage
  • more cultural diversity
  • the promotion of democracy, rule of law, and human rights
  • an investment in peace and security in Europe

Which countries can join?

Any European country can join the EU if it fulfills the membership criteria, also known as the Copenhagen criteria. For example, countries wishing to join must have

  • stable institutions that can guarantee democracy, the rule of law, human rights and the protection of minorities. 
  • a functioning market economy and the ability to cope with the competitive pressure of the EU market. 
  • the ability to take on the obligations of EU membership, including the capacity to implement all EU law and adhere to the aims of the Union. 

How does it work?

Each country that applies to join the EU must fulfil the same strict requirements and follow the same rigorous process to become a Member State. 

There are three main steps to this process, also known as the accession process. These are:  

Step 1: Candidacy

A country wishing to join the EU must submit a membership application to the Council of the EU. The Council then asks the European Commission to check the applicant country’s ability to fulfill the membership criteria.

Based on the Commission's recommendations, the Council decides whether to grant the country candidate status and to begin formal negotiations for its accession to the Union. All EU Member States must agree on this decision.

Step 2: Membership negotiations 

During membership negotiations, the candidate country prepares to implement EU laws and standards, also known as the acquis.

Throughout the negotiations, the Commission monitors the candidate's progress on these reforms and keeps the Council and European Parliament informed of this through regular reports and communications.

Step 3: Accession

Once the negotiations are complete, the Commission gives its opinion on whether the candidate is ready to become a Member State. If the Commission recommends that the candidate is ready, an accession treaty is prepared. This document details the terms and conditions of the country's EU membership.

The accession treaty must then be approved by the European Commission, the European Council and the European Parliament before being signed and ratified by all EU Member States and the candidate country. 

The candidate country officially joins the EU on the date outlined in its accession treaty.

History of enlargement

Seven enlargements have taken place since the EU was first formed by its six founding members. Today there are 27 countries in the EU. 

  1. 01-07-2013
    Seventh enlargement

    Croatia joins the EU in the most recent enlargement.

  2. 01-01-2007
    Sixth enlargement

    Bulgaria and Romania join the EU.

  3. 01-05-2004
    Fifth enlargement

    Ten new countries join the EU: Cyprus, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, and Slovenia. This is the largest enlargement in terms of people and number of countries.

  4. 01-01-1995
    Fourth enlargement

    Austria, Finland, and Sweden join the European Union (EU), the successor of the EEC following the Treaty of Maastricht in 1993. The 15 members now cover almost the whole of western Europe.

  5. 01-01-1986
    Third enlargement

    Spain and Portugal join the EEC. The number of Member States is now 12.

  6. 01-01-1981
    Second enlargement

    Membership of the EEC reaches double figures when Greece joins.

  7. 01-01-1973 
    First enlargement 

    Denmark, Ireland and the United Kingdom join the EEC, raising the number of Member States to nine.

  8. 25-03-1957
    Founding members

    Belgium, France, Germany, Italy, Luxembourg, and the Netherlands sign the Treaty of Rome. This establishes the European Economic Community (EEC), which would eventually become the EU we know today.

Potential enlargement of the EU

Further enlargement of the EU is possible, as ten aspiring members are currently involved in the accession process.

Candidate countries

These countries have been granted candidate status, and are currently reforming their national laws to align with EU rules, regulations, and standards.

Potential candidate

A potential candidate has applied to join the EU, but has not yet been granted candidate status.