Telephone numbers in the United Kingdom


In the United Kingdom and the Crown Dependencies, telephone numbers are administered by the Office of Communications. 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.
Telephone numbers are of variable length. Local numbers are supported from landlines. Numbers can be dialled with a '0'-lead prefix that denotes either a geographical region or another service. Mobile phone numbers have distinct prefixes that are not geographic, and are portable between providers.

Structure

All mobile numbers, nearly all geographic numbers, and nearly all non-geographic numbers have ten national digits after the trunk code 0. The overall structure of the UK's National Numbering Plan is:
PrefixService type
00International
01Geographic area codes
02Geographic area codes.
03Non-geographic numbers charged at standard geographic area code rates
04Not in use
05Corporate numbering and VoIP services; freephone services until June 2017
06Not in use
07Mobile telephony, personal numbering, and pagers
08Non-geographic freephone numbers, non-geographic service numbers
09Non-geographic service numbers

A short sample of geographic numbers, set out in the officially approved number groups:
NumberLocation
London
Cardiff
Leeds
Leicester
Birmingham
Liverpool
Dundee
Evesham
Oxford
Bolton
Sedbergh
Brampton

In the United Kingdom, the "area code" was historically referred to as a "subscriber trunk dialling code" or a "dialling code". United Kingdom area codes are two, three, four or, exceptionally, five digits long. Regions with shorter area codes, typically large cities, permit the allocation of more telephone numbers as the local number part has more digits. Local customer numbers are four to eight digits long. The total number of digits is ten or, very rarely, nine.
The code allocated to the largest population is for London. The code allocated to the largest area is for all of Northern Ireland. The UK Numbering Plan also applies to three British Crown dependencies – Guernsey, Jersey, and the Isle of Man – even though they are not part of the UK, these countries are closely related.

Format

Possible number formats for UK telephone numbers are:
Number length10-digit NSN9-digit NSN7-digit NSN6 digits5 digits4 digits3 digits
Number formats xx xxx
xxx xxx
xxx xxxx
xxx xxxx
xxxx xxxx
03xx xxx xxxx
055 xxxx xxxx
056 xxxx xxxx
07x xxxx xxxx
07xxx xxx xxx
0800 xxx xxxx
08xx xxx xxxx
09xx xxx xxxx		 xxxx
xx xxx
0800 xxx xxx		0800 11 11
0845 46 4x		118 xxx
116 xxx		170701470
1471
1472
1474
1475
1476
1477
1478
1479
1571
1572		999
112
100
101
105
111
119
123
141
155
159
195

Number ranges starting 01 can have National Significant Number length of 10 or 9 digits. NSN is the number of digits after the leading 0 trunk code or +44 international prefix. 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 had NSN length as 9 digits only, and was withdrawn from use on 3 June 2017. All other UK numbers have NSN length of 10 digits. There are no telephone numbers in the UK with an NSN length of 8 digits.

Geographic numbers

Standard geographic numbers

Geographic telephone numbers in the UK always have nine or ten digits after the 0 trunk code or +44 international dialling prefix.

Four-digit area codes

Four-digit area codes have either six-digit subscriber numbers or a mix of five- and six-digit subscriber numbers.
  • ' xxx xxx
This is the format used by most areas. It has a four-digit area code and a six digit subscriber number, and is known as 4+6 format. These area codes were changed by adding a "1" directly after the initial zero as a part of PhONEday in 1995. Just short of 581 areas use this format, and the area codes range from 01200 to 01998. Almost all area codes now have only six-digit subscriber numbers, but a small number of these areas also have some subscriber numbers that are only five digits in length.
01224Aberdeen22 = AB
01244Chester24 = CH
01275Clevedon27 = BR
01382Dundee38 = DU
01387Dumfries 38 = DULocal numbers cannot begin with 3
01452Gloucester45 = GL
01472Grimsby47 = GR
01473Ipswich47 = IP
01429Hartlepool42 = HA
01482Hull48 = HU
01539Kendal 53 = KELocal numbers cannot begin with 4, 5 or 6
01582Luton58 = LU
01642Teesside or Middlesbrough64 = MI
01670Morpeth67 = MP
01697Brampton, North West 69 = NWLocal numbers cannot begin with 3, 4 or 7
01733Peterborough73 = PE
01736Penzance73 = PE
01772Preston77 = PR
01782Stoke-on-Trent78 = ST
01792Swansea79 = SW
01793Swindon79 = SW
01854Ullapool85 = UL
01947Whitby94 = WH

Six of the four-digit area codes are known as "mixed" areas as they share those four digits with the twelve five-digit area codes. This leads to a restriction as to which initial digits can be used for subscriber numbers within those four-digit area codes, e.g. in the 01387 four-digit area code, subscriber numbers cannot begin with a 3 because 013873 is a separate five-digit area code; likewise in the 01946 four-digit area code, subscriber numbers cannot begin with a 7 because 019467 is a separate five-digit area code.
  • ' xx xxx
This is used for forty smaller towns which have a mixture of six and five digit local numbers, each type allocated in specific DE blocks*; e.g. in the 01647 area code numbers beginning 24 and 61 have five digits whereas all other DE blocks* within that area code have six digit numbers. The number of places with five digit subscriber numbers and an 01xxx area code has declined rapidly in recent decades. There were 511 ranges allocated across 56 different area codes in January 1998. The Big Number Change removed many, especially in Northern Ireland, and by July 2005 there were only 329 ranges in 42 codes. By April 2010 this had reduced to 324 ranges in 40 codes, with still the same number in November 2012. The 40 area codes are listed in the table below.
*A DE block is a block of numbers where the initial 0 and the next six digits after it are the same for all the subscriber numbers in the block.
01204Bolton20 = BO61–64
01208Bodmin20 = BO72–79
01254Blackburn25 = BL51–57, 59
01276Camberley27 = CR20–29, 31–38, 61–66
01297Axminster29 = AX20–24, 32–35
01298Buxton29 = BX22–28, 70–74, 77–79, 83–85
01363Crediton36 = CN82–85
01364Ashburton, Devon36 = DN72, 73
01384Dudley38 = DU70, 74–79
01386Evesham38 = EV40, 41, 45, 47–49
01404Honiton40 = HO41–47
01420Alton, Hampshire42 = HA22, 23, 80–89
01460Chard, Ilminster46 = IM30, 52–55, 57, 61–68, 72–78
01461Gretna46 = GN40
01480Huntingdon48 = HU52
01488Hungerford48 = HU71–73
01524Lancaster 52 = LA32–37, 39, 60–69Local numbers cannot begin with 2
01527Redditch60–69
01562Kidderminster56 = KM60, 66–69
01566Launceston56 = LN86
01595Lerwick56 = LW86
01606Northwich, Winsford60 = NO40–49, 74–77, 79
01629Matlock62 = MA55–57
01635Newbury63 = NE30–39, 40–49
01647Moretonhampstead64 = MH24, 61
01659Sanquhar, Nithsdale65 = NL50, 58, 66, 67, 74
01695Skelmersdale/Ormskirk50–54
01726St Austell72 = SA61, 63–69, 70–77
01744St Helens74 = SH20–29
01750Selkirk75 = SK20–23, 32, 42, 52, 62, 76, 82
01768Penrith 76 = PN882, 883, 884, 886, 887, 888Local numbers cannot begin with 3, 4 or 7
01827Tamworth82 = TA50–59, 60–69
01837Okehampton52–55, 82, 83, 89
01884Tiverton88 = TV32–35, 38
01900Workington90 = WO61–68, 85
01905Worcester90 = WO20–29
01935Yeovil93 = YE83
01946Whitehaven 94 = WH61–68Local numbers cannot begin with 7
01949Whatton94 = WH20, 21, 81
01963Wincanton96 = WN23, 31–34
01995Garstang, Wyre99 = WY61