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European Union Research

European Union Treaties

The founding treaties of the European Union are its primary legal authority. All legislation must be in policy areas cited in the treaties. EU institutions can adopt legislation, which the member states then implement. Treaties are amended to make the EU more efficient and transparent, to prepare for new member states, and to introduce new areas of cooperation.

The main European Union treaties are:

  • Treaty Establishing the European Coal and Steel Community (1951, expired 2002)
  • Treaty of Rome (1957): Established the European Economic Community and the Euratom, extended European economic cooperation beyond the original treaty.
  • Single European Act (1986)
  • Treaty on European Union (Maastricht Treaty) (1992): Set up a common foreign and security policy and common home affairs policy. 
  • Treaty of Amsterdam (1997): Renumbering and consolidation of EU treaties. Increased transparency.
  • Treaty of Nice (2001): Enlargement and enhanced Parliamentary role.
  • Treaty of Lisbon (2007): Clarifies with powers belong to the EU and which belong to member states. Greater role for European Parliament and for national parliaments. Created a EU High Representative for Foreign and Security Policy. 
  • Charter of Fundamental Rights of the European Union (2007)

Treaties are available as original versions, with amendments, and as consolidated versions. Consolidated versions incorporate, repeal, amend, and renumber sections from earlier treaties.

Find the treaty text

European Union Legislation

European Union legislation is published in the Official Journal of the European Union.  There is no official EU code, although there are unofficial consolidated versions of legislation incorporating amendments with original text.

  • L series:  Final adopted treaties and legislation
  • C series: Information and Notices. Non-binding decisions and resolutions, proposed legislation, notices of Court decisions.

The electronic version from Eur-Lex is considered official: see 2013 O.J. (L69) 1.

As of October 1, 2023, the Official Journal is published with individual act numbers instead of daily issues (as they were in print). Filter by date or date range to display acts for that date - you can then filter by topic. 

Europa: Types of Legislation

EU Monitor: Types of Legal Instruments

Types of legislation published include:

  • Treaties
  • Regulations: Legislation of general effect, applies directly, binding on member states. National legislation may still be needed to integrate into national law.
  • Directives: Binding on member states, with implementing legislation required.
  • Decisions: Binding for the EU as a whole unless stated otherwise, do not need national legislation
  • Opinions: Written statements of policy, not binding.
  • Recommendations: Apply only to the member states cited, not binding.
  • Commission Implementing Regulations and Delegated Regulations: Regulations to implement the legislative Regulations.

Finding European Union Legislation

Finding specific legislation by citation or date:

  • Official Journal of the European Union: Direct access by citation, or browse by date
  • EUR-Lex Search: Options include document citation, OJ citation, type of legislation, date, publication date
  • Google: A Google search by citation (regulation number or OJ citation) may work. But check for status of the legislation you find.

Searching for legislation:

  • EUR-Lex Advanced Search: Search by title, text, type of legislation, date, theme, related documents
  • EUR-Lex Consolidated Texts: Search for unofficial consolidated acts 
  • Westlaw: Find EU legislation in International Materials
  • vLex Justis: EU legislation in materials by jurisdiction, Europe
  • Most European databases of national legislation will also include EU legislation

Find European Union legislation by subject or policy area:

  • Summaries of EU Legislation: Summaries grouped into 32 policy areas. Include citations and links to legislation in force. Summaries cite related acts, amendments, and repeals. Browse by policy area, or use the advanced search of the summaries by title, text, date, EuroVoc thesaurus, or topic. There is also a glossary of summaries to find explanations of terms used, some with links to relevant treaties and legislation. 
  • EuroVoc Thesaurus: Browse EU legislation and caselaw using the EU thesaurus domains, or search within the policy areas
  • European Commission Departments and Agencies: Department websites frequently  include legislation and implementation reports on policy areas, with links and background information. 
  • From other legislation in EUR-Lex: Document Information page has links to EUROVOC descriptors, subjects, and related legislation and documents

Implementing Legislation

Directives require European Union member states to achieve a certain result, but it is up to the member states to adopt measures to incorporate or transpose them into national law. Transposition into national law must take place by a deadline set when the directive is adopted, generally within two years.

To find national legislation implementing the directives, find tables of implementing measures and citations to national legislation.

EUR-Lex: One of the Advanced Search Options is National Transposition as a Collection. Enter the Directive citation in Documents Related to a Legislative Procedure.

EUR-Lex: Directives found in EUR-Lex include a list of National Transposition measures. The entry for each country includes a citation and sometimes the document or a link to the national legislative website.

Westlaw: Directives available in European Union Legislation include Analysis, including the Document Details and National Measures from EUR-Lex. 

N-Lex: The EU's "common gateway to National Law." Use EuroVoc standardized terminology, with machine translation, to search national legislation, including the transposition measures implementing the directives. 

To find sources and links to European national legislation, you can use the Foreign Law Guide database, the Bluebook's T2 tables on foreign jurisdictions, or the Law Library of Congress Guide to Law Online.


European Union: The Lawmaking Process

Legislative Procedure and History

EUR-Lex: Lawmaking Procedures. Search for legislative documents by title, text, procedure, institution, status, legal basis, or theme.

COM Documents and Preparatory Acts: Find pending legislation and legislative history by citation or date.

European Council and Council of the European Union: Public Register of Council Documents

European Parliament: Legislative Observatory. Database of procedure records and documents from the EU Parliament. Find most recent documents by session. 

EP Thinktank: European Parliament Blog. Tracks policies, publications, legislation in progress, and current topic areas of interest.

EU Policy and Topical Information

European Commission Directorates-General, Departments, and Executive Agencies: Administrative agencies responsible for broad areas of EU policy. Department websites include policy information, relevant legislation, decisions, and administrative cases, and agency publications. Find reports on implementation of Directives and other legislation and policies, and links to treaty articles and legislation.

There is also a search page by keyword or subject for EU institutions and bodies.

European Commission Strategy and Priorities: Find featured policy priorities, and a subject list of policies and initiatives leading to implementation reports, legislation, and publications

European Union Actions by Topic: Topic pages with links to Summaries of EU Legislation, policy information, agencies, publication, and press releases

Delegation of the EU to the United States: Policies and travel information of interest to US citizens

Publications Office of the European Union: Find EU publications by search, subject area, institution or agency author, or date, most available for free PDF download

European Union Newsroom: Highlights page with news stories partly arranged by institution or policy area, with links to latest legislation and proposals. Pres releases are also available to browse by topic or source.