List of dialling codes in the United Kingdom

This is a list of telephone dialling codes in the United Kingdom, which adopts an open telephone numbering plan for its public switched telephone network. The national telephone numbering plan is maintained by Ofcom, an independent regulator and competition authority for the UK communications industries. This list is based on the official standard, but includes defunct codes and historical changes, including the derivation of the two letter identities, in cases where known.^[1][2][3] Dialling codes do not correspond to specific political boundaries: for example, the Coventry dialling code covers a large area of Warwickshire and the Manchester dialling code covers part or all of several neighbouring towns.

When dialling within the country, all area codes are preceded by the national trunk prefix 0, which has been included in all listings in this article. 0 was traditionally the number dialled for the operator for long-distance calls before subscriber trunk dialling (STD) was introduced, and so was retained as a prefix for direct-dialled calls. In the majority of areas, the area code still corresponds to the original STD letter code. When dialling from abroad, the 0 prefix is not dialled. When dialling within the same area, the area code is not needed, save for a handful of areas that do require this. When calling from a mobile telephone or through a VoIP service, such as BT's 'Digital Voice', the area code is always needed.