UK Telephone Code Misconceptions - History of The Confusion

History of The Confusion

When the UK's original STD codes were allocated in the late 1950s, London was given the code 01. However, relatively few subscribers could dial trunk calls, so the 01 code was not generally included as part of the published telephone number. In the early 1960s London telephones still had exchange names, the first three letters having to be dialled before the four-digit local number, e.g. ABBey 1234 (London Transport).

In the mid 1960s, All Figure Numbers (AFNs) were introduced in London and five other large cities because the number of meaningful letter combinations was becoming exhausted. The STD codes were incorporated as part of the AFN, ABBey 1234 becoming 01-222 1234. However, callers in London were still instructed to dial only the seven digits (those after the hyphen) when calling other London numbers because an error message would result if the 01 code were dialled. This restriction was eventually phased out as exchanges were modernised, and the STD code was shown in brackets to standardise with the format used in non-AFN areas, e.g. Canterbury (01227) 123456. The term 'Area Code' also replaced 'STD Code' which had become outdated.

In May 1990 the single London area was split into two areas, because of increased demand. Inner London was given the code 071, for example, (071) 222 1234, and the rest 081. Consequently, there potentially then existed two separate numbers, because they were in different area codes, and (081) 222 1234 could also be valid. The local numbers remained as seven digits. This doubled the numbers available for London, but it also meant that a person from outer London, when calling a central London number (and vice versa), had to dial the full number including prefix.

To free up more numbers for future use, on Easter Sunday, 16 April 1995 (dubbed "PhONEday"), an extra digit "1" was inserted after the initial zero into all except five geographical area codes nationwide, so inner and outer London became 0171 and 0181 respectively — for example (0171) 222 1234. At the same time, those five other places gained a brand new 011x area code.