National dialling only

United Kingdom telephone numbers

Location of the United Kingdom
Location
Country	United Kingdom
Continent	Europe
Regulator	Ofcom
Type	Open
NSN length	7, 9, 10
Typical format	various, see text
Numbering plan	The National Telephone Numbering Plan
Last updated	13 December 2013
Access codes
Country calling code	+44
International call prefix	00
Trunk prefix	0
List of United Kingdom dialing codes

Telephone numbers in the United Kingdom are administered by the UK government's Office of Communications (Ofcom). For this purpose Ofcom established a telephone numbering plan, known as the National Telephone Numbering Plan, which is the system for assigning telephone numbers to subscriber stations.

Since 28 April 2001, almost all geographic numbers and most non-geographic numbers have 9 or 10 national (significant) numbers after the "0" trunk code. All mobile telephone numbers have 10 national (significant) numbers after the "0" trunk code. The overall structure of the UK's National Numbering Plan is:

A short sample of geographic numbers, set out in the officially approved (Ofcom) number groups:

In the United Kingdom, area codes are two, three, four, or, rarely, five digits long (after the initial zero). Regions with shorter area codes, typically large cities, permit the allocation of more telephone numbers as the local number portion has more digits. Local customer numbers are four to eight figures long. The total number of digits is ten, but in a very few areas the total may be nine digits (after the initial zero). The "area code" is also referred to as an "STD (code)" (subscriber trunk dialling) or a "dialling code" in the UK.

The code allocated to the largest population is (020) for London. The code allocated to the largest area is (028) for all of Northern Ireland. The UK Numbering Plan also applies to three British Crown dependencies—Jersey, Guernsey and the Isle of Man—even though they are not part of the UK itself.

Possible number formats for UK telephone numbers are as follows:

118
105

Number ranges starting 01 can have NSN length as 10 or 9 digits. The 0800 range can have NSN length as 10, 9 or 7 digits. The 0845 range can have NSN length as 10 or 7 digits. The 0500 range has NSN length as 9 digits only. There are no telephone numbers in the UK with an NSN length of 8 digits.