There are currently nine states recognised as candidates for membership of the European Union: Albania, Bosnia and Herzegovina, Georgia, Moldova, Montenegro, North Macedonia, Serbia, Turkey, and Ukraine. Kosovo (the independence of which is not recognised by five EU member states) formally submitted its application for membership in 2022 and is considered a potential candidate by the European Union. Due to multiple factors, talks with Turkey are at an effective standstill since December 2016.
Six candidates are currently engaged in active negotiations: Montenegro (since 2012), Serbia (since 2014), Albania (since 2022), North Macedonia (since 2022), Moldova and Ukraine (since 2024). The most advanced stage of the negotiations, defined as meeting the interim benchmarks for negotiating chapters 23 and 24, after which the closing process for all chapters can begin, has so far been reached by Montenegro (in 2024) and by Albania (in 2026). Montenegro's declared political goal is to complete its negotiations by the end of 2026 and achieve membership of the EU by 2028, whereas Albania aims to conclude negotiations by 2028 at the latest, potentially joining the EU shortly after Montenegro.
The accession criteria are included in the Copenhagen criteria, agreed in 1993, and the Treaty of Maastricht (Article 49). Article 49 of the Maastricht Treaty (as amended) says that any "European state" that respects the "principles of liberty, democracy, respect for human rights and fundamental freedoms, and the rule of law," may apply to join the EU. Whether a country is European or not is subject to political assessment by the EU institutions. Past enlargement since the foundation of the European Union as the European Economic Community by the Inner Six states in 1958Current Article 1 of the Treaty on European Union reads: "The Union shall be founded on the present Treaty and on the Treaty on the Functioning of the European Union. Those two Treaties shall have the same legal value. The Union shall replace and succeed the European Community". brought total membership of the EU to twenty-eight, although, as a result of the withdrawal of the United Kingdom, the current number of EU member states is twenty-seven.
Of the four major Western European countries that are not EU members, Norway, Switzerland, and Iceland have submitted membership applications in the past but subsequently froze or withdrew them, while the United Kingdom is a former member, as the only country to ever leave the EU. Norway, Switzerland, and Iceland, as well as Liechtenstein, participate in the EU Single Market and also in the Schengen Area, which makes them closely aligned with the EU; none, however, are in the EU Customs Union.
Current agenda and applicants
As of 2026, the enlargement agenda of the European Union regards three distinct groups of states: Western Balkans: Albania, Bosnia and Herzegovina, Kosovo, Montenegro, North Macedonia, and Serbia Association Trio: Georgia, Moldova, and Ukraine Turkey
These states have all submitted applications for accession to the EU, which is the first step of a long, multi-year process. They must subsequently negotiate the specific terms of their Treaty of Accession with the current EU member states, and align their domestic legislation with the accepted body of EU law (acquis communautaire), along with ensuring an appropriate level of implementation thereof, before joining.
There are other potential member states in Europe that are not formally part of the current enlargement agenda, either due to having a domestic political debate on potential membership, or having withdrawn a previous membership or application for membership. These other potential member states could be included on the enlargement agenda at some point of time in the future, if their foreign policy changes and paves the way for submitting an application, and the EU subsequently recognises them as an applicant or candidate.
Historically, the norm was for enlargements to consist of multiple entrants simultaneously joining the European Economic Community (1958–1993) and the EU (since 1993). The only previous enlargements of a single state were the 1981 admission of Greece and the 2013 admission of Croatia. However, following the significant effect of the fifth enlargement in 2004, EU member states have decided that a more individualised approach will be adopted in the future, although the entry of pairs or small groups of countries may coincide.
Procedure to become an EU member state For an applicant to become a member state of the EU, several procedural steps need to get passed. These steps will move the status of the state from applicant (potential candidate) to candidate, and later move on to the status of a negotiating candidate. The status as a negotiating candidate is reached by the mutual signing of a negotiation framework at the first intergovernmental conference. The start of substantial negotiations with the EU is subsequently marked by the opening of the first negotiating chapters at a second intergovernmental conference. All 35 chapters of the accepted body of EU law (divided into 6 clusters) must be opened and closed during subsequent additional intergovernmental conferences for a state to conclude the negotiations by the signing of an accession treaty.
Following a reform in 2020, the 35 chapters have been divided into six main clusters, where all five chapters of the first cluster are supposed to be opened together at the same time. The opening of chapters, which after the reform occur with several chapters opened together cluster-wise, can only happen by a unanimous decision by the Council of the European Union once the screening procedure report has been completed for the specific chapters (outlining all needed legislative changes to comply with EU law), while there can also be set some "opening benchmarks" requiring a certain amount of legislative changes/implementation to be met even before the opening of the chapters. The closure of a chapter is done provisionally by a unanimous decision by the Council of the European Union once the state demonstrates that it has implemented and aligned its domestic legislation with the EU law, for each specific chapter in concern.
There are no requirements for completion of the screening procedure for all 35 negotiating chapters, before the start of the first and second intergovernmental conferences.
Due to the Primacy of European Union law over the constitution of member states with few exceptions a potential enlargement can require a referendum related to the accession to the European Union or a constitutional amendment.
Western Balkans
The 2003 European Council summit in Thessaloniki set the integration of the Western Balkans as a priority of EU expansion.
Slovenia was the first former Yugoslav country to join the EU in 2004, followed by Croatia in 2013.
Albania, Bosnia and Herzegovina, Montenegro, North Macedonia, and Serbia have all been officially granted candidate status. Kosovo, which is claimed by Serbia and not recognised by 5 EU states, applied on 14 December 2022 and is considered a potential candidate by the European Union.
Serbia, Albania, and Montenegro, as the most advanced candidates in their negotiation processes with the EU, may join the EU sometime between 2028 and 2030, considering the 18 to 24-month ratification process, which starts after the negotiations are completed. Montenegro's declared political goal is to complete its negotiations by the end of 2026 and achieve membership of the EU by 2028.
The European Council had endorsed starting negotiations with Albania and North Macedonia on 26 March 2020, however, the negotiation process was blocked by Bulgaria for over two years. In June 2022, French President Emmanuel Macron submitted a compromise proposal which, if adopted by both countries, would pave the way for the immediate adoption of negotiating frameworks for North Macedonia and Albania by the EU Council and for the organisation of intergovernmental conferences with them. On 24 June 2022, Bulgaria's parliament approved the revised French proposal to lift the country's veto on opening EU accession talks with North Macedonia, with the Assembly of North Macedonia also doing so on 16 July 2022, allowing accession negotiations to begin. On the same day, the start of negotiations was set for 19 July 2022.
On 8 November 2023, the European Commission adopted a new Growth Plan for the Western Balkans, with the aim of bringing them closer to the EU through offering some of the benefits of EU membership to the region in advance of accession. The Growth Plan provides €6 billion in financial grants and loans for the entire region in return for the implementation of structural reforms. Besides the core financial support of the growth plan, one of the additional embedded priority actions is granting access to the Single Euro Payments Area.
On 8 November 2023, the European Commission recommended opening negotiations with Bosnia and Herzegovina once the necessary degree of compliance with the membership criteria is achieved. On 12 March 2024, the European Commission recommended opening EU membership negotiations with Bosnia and Herzegovina, citing the positive results from important reforms the country enacted. On 21 March 2024, all 27 EU leaders, representing the European Council, gathered for a summit in Brussels, where they unanimously granted conditional approval for opening EU membership negotiations with Bosnia and Herzegovina. On 17 December 2024, the Council reiterated that they still needed to receive an approved Growth Plan reform package along with a national programme for the adoption of EU law, and that the country should appoint a chief negotiator and a national IPA III coordinator, before the adoption of a negotiation framework can happen as the next step of the process for Bosnia and Herzegovina.