In European politics, the EC was the European Communities, the official name for the union that was commonly known as the EEC or the European Community. In fact it was Communities, plural, because it consisted of three: the European Economic Community (the EEC or Common Market), together with the European Coal and Steel Community (ECSC, founded 1951) and the European Atomic Energy Community (Euratom, founded 1957). With the Treaty of Maastricht, the EC, though continuing to exist, was subsumed into the new European Union or EU.

Confusingly, with the Single European Act the EEC was renamed the European Community, singular, while continuing to be one of the members of the EC (plural). (Thanks Albert Herring.) Also, EC can now stand for European Commission, one of the governing bodies of the EU.

In London, EC means East Central and is the postal district roughly covering the City of London, that is the CBD, and Clerkenwell to the north. There are now four postcode prefixes, EC1 to EC4.

  1. EC1 covers Clerkenwell and Finsbury, going from Angel tube in the north down City Road to Old Street and the Bunhill Fields burial ground. It takes in St Bartholomew's Hospital and Smithfield Meat Market in the south, and is bounded to the west along Holborn, Gray's Inn Road, and Rosebery Avenue.
  2. EC2 covers the Barbican, Broadgate, and the Bank of England. It is bounded to the south by Cheapside, Poultry, and Threadneedle Street, to the east by Bishopsgate and Shoreditch High Street, and to the north by Old Street.
  3. EC3 covers Aldgate and the Tower of London, taking in the Lloyd's of London building and the Monument.
  4. EC4 covers all the riverside from London Bridge in the east to Temple Bar and the Temples in the west, taking in St Paul's Cathedral, Bow Bells, and the Old Bailey.

In the Caribbean, EC means East Caribbean, particularly in relation to the currency, the EC dollar, formerly known as the British West Indies (or BWI) dollar. This is shared by most of the smaller former British colonies, but not Jamaica, Trinidad and Tobago, or Barbados.

Other meanings include: Emergency Contraception, Environment Canada, Engelhard Corporation (stock exchange code).

EC is also often found in European Union law, where it refers to the Treaty Establishing the European Community as amended by the Treaty of Amsterdam: "Article 28 EC," for instance.

However, "Article 28 EC" is not the same as "Article 28 of the EC Treaty." In fact, Article 28 EC is actually Article 30 of the EC Treaty. This is because writing out the name of the treaty indicates that the author is referring to the original treaty, which was renumbered after the Treaty of Amsterdam.

Being able to convert the old article numbers to the new article numbers can be a very useful skill in dealing with EU law.
