ISO 3166-2:GB

ISO 3166-2:GB is the entry for the United Kingdom in ISO 3166-2, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), which defines codes for the names of the principal subdivisions (e.g., provinces or states) of all countries coded in ISO 3166-1. The codes and structures used are provided to the ISO by British Standards and the Office of National Statistics.

Currently for the United Kingdom, ISO 3166-2 codes are defined for the following subdivisions:

• England:
  • 27 two-tier counties
  • 32 London boroughs
  • 36 metropolitan districts
  • 55 unitary authorities (includes 5 single-tier counties; Cornwall, Durham, Northumberland, Shropshire & Wiltshire )
  • 1 city corporation (i.e., the City of London)
• Northern Ireland: 26 district council areas
• Scotland: 32 council areas
• Wales: 22 unitary authorities

Each code consists of two parts, separated by a hyphen. The first part is GB, the ISO 3166-1 alpha-2 code of the United Kingdom. The second part is three letters, which is the British Standard BS 6879 three-letter code of the subdivision.

The four constituent parts of the United Kingdom, i.e., England, Northern Ireland, Scotland, and Wales (whose status is described as either "country", or "province"), are also assigned codes, as well as three other geopolitical terms which are "included for completeness":

• England and Wales (consisting of England and Wales)
• Great Britain (consisting of England, Scotland, and Wales)
• United Kingdom (consisting of England, Northern Ireland, Scotland, and Wales)

Each code consists of three letters, which is also taken from BS 6879.

The ISO 3166-1 alpha-2 code UK is also exceptionally reserved for the United Kingdom on the request of the country. Its main usage is the .uk internet ccTLD.