Telephone numbers in the UK starting with '01' or '02' are linked to a specific geographical location. The number can be split into two parts. The first part is the Arewa Code, which identifies the location. The Area Code can range from 3 digits in length, as is the case for London ('020') to 6 digits for small locations (such as '019467' for Gosforth). The majority of Area Codes though are 5 digits in length (such as '01494' for High Wycombe), although there are a number of 4 digits codes, such as '0151' for Liverpool. The remainder of the number is the subscriber number, which is always unique within the area of the Area Code and identifies an individual home or business telephone line.
While there can only be one individual having a specific subscriber number in a particular area, it is possible for the same number to exist in other areas. So, the subscriber number '456789', can only appear once in High Wycombe's '01494' area but could also exist in the '01892' (Tunbridge Wells) and '01685' (Merthyr Tydfil) areas.
In most areas, two land line numbers that share the same Area Code can call each other using just the subscriber number. So, the owner of telephone number '456789' in Maidstone could call the Maidstone number '987654', just by dialing '987654'. But, if they wanted to call the owner of '987654' in Sevenoaks, they would have to call the full number, including the Area Code - '01732 987654'.
Area Code coverage
In general, an Area Code covers one town or city, but there are a few codes covering multiple locations, such as '028', which covers the whole of Northern Ireland and '023', which covers Southampton and Portsmouth. In these cases, individual locations can be identified by the first digits following the area code.
At the bottom of this page, you will find a list of all the current Area Codes and the location that they cover.
'01' and '02' numbers should not be confused with '03' numbers, which are not linked to a specific geographical location.
History of UK Area Codes
The format of Area Codes in the UK have gone through a number of changes since the mid 1990s. These have been necessary to allow for the ever increasing demand for numbers, due to the introduction of mobile phones and VoIP.
You can find more information on the changes that area codes have gone through on our Area Code history page.
Current Area Codes
You can find a list of all 610 Area Codes currently in use on our Area Codes List page.