What is the European Union? How the EU works

The European Union is a political and economic union of 27 European countries that have agreed to make some laws together and apply them across all their territory. Its core is a single market, where goods, services, money and people move freely, and 21 of its members share a currency, the euro. The EU is more than an alliance and less than a country: its members stay sovereign states, but in the areas they have pooled, EU law overrides national law.

In short

• The EU grew from a 1951 coal and steel pact among six countries into a union of 27 with a single market and, for most members, one currency.
• The Commission proposes laws; the elected Parliament and the Council of national ministers amend and pass them; the Court of Justice settles disputes.
• Countries join by a long negotiation that every member must approve, and can leave under Article 50, as the United Kingdom did in 2020.

How did the EU begin?

The EU started as a plan to make another war between France and Germany impossible. On 9 May 1950, French foreign minister Robert Schuman proposed pooling the two countries' coal and steel industries, the raw materials of war, under a shared authority. The Treaty of Paris, signed on 18 April 1951, created the European Coal and Steel Community, with six members: Belgium, France, West Germany, Italy, Luxembourg and the Netherlands.

Year	What happened
1951	Treaty of Paris creates the European Coal and Steel Community (six members)
1957	Treaties of Rome create the European Economic Community, a common market, in force from 1958
1973	Denmark, Ireland and the United Kingdom join
1993	The Maastricht Treaty takes effect and creates the European Union
1999	The euro launches for banks and markets; notes and coins follow in 2002
2004	Ten countries join, most of them in Central and Eastern Europe
2009	The Lisbon Treaty reshapes the institutions and adds Article 50, the exit clause
2013	Croatia joins, the most recent new member
2020	The United Kingdom leaves on 31 January, after its 2016 referendum
2026	Bulgaria becomes the 21st country to use the euro, on 1 January

The members joined in waves, which the EU's list of countries records with each one's year of entry.

What does the EU actually do?

The single market is the heart of the EU. It removes tariffs and border checks on trade between members and sets one rulebook for products, so a toy or a car approved in one member state can be sold in all of them. Its "four freedoms" are the free movement of goods, services, capital and people, which also lets EU citizens live and work in any member country.

On top of that, the EU sets common rules where members have agreed to act together: competition law, trade deals with the rest of the world, farming and fisheries subsidies, consumer and data protection, and environmental standards. It negotiates trade as one bloc, which is why countries outside it sign trade agreements with the EU rather than with each member.

Two well-known pieces are related to the EU but are not the same thing. The euro is used by 21 of the 27 members, according to the EU's own list, and managed by the European Central Bank. The Schengen Area, which removes passport checks at internal borders, includes most EU members and a few non-members such as Norway and Switzerland. Defense, taxes and most of health and education stay largely in national hands.

Who makes the decisions?

The EU's names confuse almost everyone, because three of its bodies have "Council" in their name or role and only two of them belong to the EU.

Body	Who sits in it	What it does
European Commission	One commissioner per member state, nominated by governments; Parliament approves them as a team	Proposes new laws, enforces the treaties, runs day-to-day policy, negotiates trade
European Parliament	720 members elected directly by citizens every five years (since 2024)	Amends and votes on laws with the Council, approves the budget and the Commission
Council of the European Union	A minister from each member government, by subject	Amends and votes on laws with Parliament
European Council	The heads of state or government of all 27, plus its president and the Commission's	Sets overall direction and settles the hardest political questions; doesn't pass laws
Court of Justice of the European Union	Judges from every member state	Rules on what EU law means; its rulings bind national courts
Council of Europe	46 countries in 2025, including non-EU members	A separate organization, home of the European Court of Human Rights; not part of the EU

Most EU laws pass by the ordinary legislative procedure: the Commission proposes, and Parliament and the Council must both agree on the same text. In the Council, most decisions need a qualified majority, 55% of member states representing at least 65% of the EU's population. Foreign policy, taxation, new members and treaty changes need unanimity, so any one country can block them.

How does an EU law get made? One example

The rule that phones sold in the EU must charge by USB-C shows the process. The Commission published its proposal in September 2021, as an amendment to an existing law on radio equipment. Parliament adopted its position on 4 October 2022, and the Council approved the same text on 24 October, according to the European Parliament's record of the procedure. The law was published in December 2022 as a directive, which each member state then wrote into its own law.

Manufacturers got two years to adapt. The rules applied from 28 December 2024 to phones, tablets, cameras, headphones and similar devices, and from 28 April 2026 to laptops. Because the EU is one of the world's largest markets, manufacturers changed products sold far beyond its borders, an effect often called the "Brussels effect".

How does a country join or leave?

Any European country that respects the EU's values of democracy, the rule of law and human rights can apply under Article 49 of the Treaty on European Union. It must meet the Copenhagen criteria, set in 1993: stable democratic institutions, a working market economy, and the capacity to adopt the whole body of EU law. Negotiations run chapter by chapter and usually take many years, and every existing member must agree to let a new one in. The Commission's enlargement pages listed ten countries in that queue in 2026: Albania, Bosnia and Herzegovina, Georgia, Moldova, Montenegro, North Macedonia, Serbia, Türkiye and Ukraine as candidates, and Kosovo as a potential candidate.

Leaving runs through Article 50. A member notifies the European Council, and the two sides have two years to negotiate an exit deal unless they agree to extend. The United Kingdom is the only member to have left: it voted to leave in June 2016, triggered Article 50 in March 2017 and left on 31 January 2020.

Still argued

How much power the EU should have is a live argument in nearly every member state. Supporters of closer integration argue that pooling decisions gives Europeans more weight in trade, climate and security than 27 separate countries could have, and that the single market has made members richer. Critics argue that too many decisions are taken far from voters, by a Commission that is appointed rather than elected, and that one set of rules fits poorly across very different economies. Both sides point to evidence, from economic studies of the single market to low turnout in European elections.

The EU sits alongside other international bodies with different jobs: NATO handles collective defense, which most EU members also belong to; the United Nations works at a global level; and the G7 brings the largest advanced economies, including several EU members and the EU itself, to one table. Its institutions are a working experiment in democracy above the level of a nation.

Check yourself

• Without looking back: what is the difference between the European Council, the Council of the European Union and the Council of Europe?
• What does the single market let a business or a citizen do that they couldn't otherwise?
• Why can one member state block a new country from joining but not a new product rule?

Sources

• The first treaties — European Parliament, Fact Sheets on the European Union
• Country profiles — European Union
• Countries using the euro — European Union, 2026
• Radio Equipment Directive, common charger for electronic devices: procedure 2021/0291(COD) — European Parliament Legislative Observatory
• EU common charger rules: power all your devices with a single charger — European Commission, 2024
• Candidate countries and potential candidates — European Commission