The acquis communautaire (French for "Community acquis," often shortened to "the acquis") refers to the full body of common rights and obligations binding on all European Union member states. It includes the EU treaties, secondary legislation (regulations, directives, decisions), case law of the Court of Justice of the European Union, declarations and resolutions, international agreements concluded by the EU, and joint actions in foreign and security policy.
Candidate countries seeking EU accession must adopt, implement, and enforce the entire acquis before joining. For negotiation purposes, the acquis is divided into chapters (currently 35, covering areas such as free movement of goods, competition policy, agriculture, judiciary and fundamental rights, and financial controls). Each chapter is opened and closed individually during accession talks, with the European Commission issuing screening reports and benchmarks.
The concept was formalized through successive enlargements and is reinforced by the Copenhagen criteria, adopted by the European Council in June 1993, which require candidates to have the administrative and judicial capacity to take on the obligations of membership. The Treaty on European Union (Article 49 TEU) provides the legal basis for accession and implicitly for the acquis requirement.
Importantly, the acquis is dynamic: it expands as the EU adopts new legislation. Candidates negotiating today face a substantially larger body of law than those who joined in 2004. Transitional arrangements are sometimes granted (for example, on labor mobility or environmental compliance), but permanent opt-outs from the acquis are rare and politically sensitive — the UK, Denmark, and Ireland historically negotiated specific opt-outs in areas such as the euro, Schengen, or justice and home affairs.
The acquis also features in association and trade frameworks. The European Economic Area (EEA) agreement requires Norway, Iceland, and Liechtenstein to adopt large portions of the internal-market acquis, and Stabilisation and Association Agreements with Western Balkan states involve progressive alignment.
Example
During its 2022 accession negotiations, Montenegro had opened all 33 screened chapters of the acquis with the European Commission but provisionally closed only three.
Frequently asked questions
Permanent opt-outs are rare and require unanimous agreement from member states. Most flexibilities take the form of time-limited transitional periods rather than permanent carve-outs.
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