rangecheck

0203 area code: London numbers starting 020 3

0203 is not a separate area code. It is London (020) followed by local numbers starting 3.

9,210,000 numbers are allocated in 921 blocks to 169 listed holders (Ofcom, 14 Oct 2026).

Check a 0203 number privately

Number ranges registered under 020 3

020 3 blocks: holder, status and allocation date
Number rangeListed holderStatusAllocation date
020 30000000 – 020 30009999 Digital Mail Limited Allocated 2005-06-07
020 30010000 – 020 30019999 Syntec Limited Allocated 2005-06-30
020 30020000 – 020 30029999 Gamma Telecom Holdings Limited Allocated 2005-06-28
020 30030000 – 020 30039999 Colt Technology Services Allocated 2005-06-20
020 30040000 – 020 30049999 Gamma Telecom Holdings Limited Allocated 2005-06-28
020 30050000 – 020 30059999 Gamma Telecom Holdings Limited Allocated 2005-06-28
020 30060000 – 020 30069999 Gamma Telecom Holdings Limited Allocated 2005-06-28
020 30070000 – 020 30079999 BT Allocated 2005-07-26
020 30080000 – 020 30089999 Verizon UK Limited Allocated 2005-06-28
020 30090000 – 020 30099999 Verizon UK Limited Allocated 2005-10-11
020 30100000 – 020 30109999 BT Allocated 2005-06-17
020 30110000 – 020 30119999 VoiceHost Limited Allocated 2010-06-22
020 30120000 – 020 30129999 Invade International Ltd Allocated 2016-01-12
020 30140000 – 020 30149999 Lumen Technologies UK Limited Allocated 2006-01-09
020 30150000 – 020 30159999 Sky UK Limited Allocated 2013-06-05
020 30160000 – 020 30169999 Sky UK Limited Allocated 2013-06-05
020 30170000 – 020 30179999 Six Degrees Technology Group Limited Allocated 2020-04-08
020 30180000 – 020 30189999 Barritel Limited Allocated 2006-02-13
020 30190000 – 020 30199999 Fuse 2 Communications Ltd Allocated 2024-01-22
020 30200000 – 020 30209999 GCI Network Solutions Limited Allocated 2017-04-25
020 30210000 – 020 30219999 Digital Space Group Limited Allocated 2016-04-12
020 30220000 – 020 30229999 BT Allocated 2005-06-17
020 30230000 – 020 30239999 Colt Technology Services Allocated 2005-06-20
020 30240000 – 020 30249999 BT Allocated 2006-02-02
020 30250000 – 020 30259999 Gamma Telecom Holdings Limited Allocated 2023-05-18
020 30260000 – 020 30269999 Simwood eSMS Limited Allocated 2006-07-18
020 30270000 – 020 30279999 BT Allocated 2006-02-02
020 30280000 – 020 30289999 Virgin Media Limited Allocated 2014-02-25
020 30300000 – 020 30309999 Served Up Limited Allocated 2008-06-03
020 30310000 – 020 30319999 Gamma Telecom Holdings Limited Allocated 2005-06-28
020 30330000 – 020 30339999 BT Allocated 2005-06-17
020 30340000 – 020 30349999 Orbtalk Limited Allocated 2014-12-08
020 30360000 – 020 30369999 Colt Technology Services Allocated 2005-06-20
020 30370000 – 020 30379999 Colt Technology Services Allocated 2006-02-23
020 30380000 – 020 30389999 Colt Technology Services Allocated 2006-02-23
020 30390000 – 020 30399999 VoiceHost Limited Allocated 2010-06-22
020 30400000 – 020 30409999 Redcentric Solutions Limited Allocated 2015-06-05
020 30410000 – 020 30419999 4D Interactive Ltd Allocated 2007-01-17
020 30420000 – 020 30429999 Virgin Media Limited Allocated 2006-06-02
020 30430000 – 020 30439999 Verizon UK Limited Allocated 2005-06-28
020 30440000 – 020 30449999 BT Allocated 2005-06-17
020 30450000 – 020 30459999 Virgin Media Limited Allocated 2006-06-09
020 30460000 – 020 30469999 RingGo Limited Allocated 2006-06-14
020 30470000 – 020 30479999 Colt Technology Services Allocated 2006-09-04
020 30480000 – 020 30489999 Colt Technology Services Allocated 2006-09-04
020 30490000 – 020 30499999 Colt Technology Services Allocated 2006-09-04
020 30510000 – 020 30519999 Magrathea Telecommunications Limited Allocated 2007-01-26
020 30530000 – 020 30539999 Gamma Telecom Holdings Limited Allocated 2013-05-29
020 30540000 – 020 30549999 CINOS LIMITED Allocated 2022-03-24
020 30550000 – 020 30559999 BT Allocated 2005-06-17
020 30560000 – 020 30569999 Six Degrees Technology Group Limited Allocated 2020-04-08
020 30570000 – 020 30579999 Verizon UK Limited Allocated 2006-09-01
020 30580000 – 020 30589999 Digital Space Group Limited Allocated 2006-02-07
020 30590000 – 020 30599999 Colt Technology Services Allocated 2007-01-02
020 30600000 – 020 30609999 Verizon UK Limited Allocated 2005-06-28
020 30620000 – 020 30629999 BT Allocated 2006-12-11
020 30630000 – 020 30639999 Vodafone Ltd (C&W) Allocated 2019-04-01
020 30640000 – 020 30649999 Voicetec Systems Ltd Allocated 2006-06-22
020 30650000 – 020 30659999 Nextec UK Limited Allocated 2013-12-06
020 30660000 – 020 30669999 BT Allocated 2005-06-17
020 30670000 – 020 30679999 BT Allocated 2005-08-01
020 30680000 – 020 30689999 BT Allocated 2005-08-01
020 30690000 – 020 30699999 BT Allocated 2005-08-01
020 30700000 – 020 30709999 Vodafone Ltd (C&W) Allocated 2013-10-01
020 30710000 – 020 30719999 BT Allocated 2005-08-01
020 30720000 – 020 30729999 BT Allocated 2005-08-01
020 30730000 – 020 30739999 BT Allocated 2005-08-01
020 30740000 – 020 30749999 BT Allocated 2005-08-01
020 30750000 – 020 30759999 BT Allocated 2005-08-01
020 30760000 – 020 30769999 BT Allocated 2005-08-01
020 30770000 – 020 30779999 BT Allocated 2005-06-17
020 30780000 – 020 30789999 BT Allocated 2005-08-01
020 30800000 – 020 30809999 BT Allocated 2005-06-17
020 30810000 – 020 30819999 Atlas Interactive Group Limited Allocated 2005-10-28
020 30820000 – 020 30829999 Vodafone Ltd (C&W) Allocated 2013-10-01
020 30840000 – 020 30849999 BT Allocated 2006-12-11
020 30860000 – 020 30869999 Vodafone Ltd (C&W) Allocated 2013-10-01
020 30880000 – 020 30889999 Colt Technology Services Allocated 2020-02-17
020 30890000 – 020 30899999 BT Allocated 2006-12-11
020 30910000 – 020 30919999 Sky UK Limited Allocated 2013-06-05
020 30920000 – 020 30929999 TalkTalk Communications Limited Allocated 2013-07-16
020 30930000 – 020 30939999 BT Allocated 2013-07-19
020 30940000 – 020 30949999 Square Systems Limited Allocated 2006-09-06
020 30950000 – 020 30959999 Andrews & Arnold Ltd Allocated 2006-10-13
020 30960000 – 020 30969999 Voiceflex Limited Allocated 2013-07-19
020 30970000 – 020 30979999 WAVECREST NETWORKS LIMITED Allocated 2019-12-16
020 30980000 – 020 30989999 Gamma Telecom Holdings Limited Allocated 2016-01-28
020 31000000 – 020 31009999 Colt Technology Services Allocated 2005-06-20
020 31010000 – 020 31019999 Alphatalk Limited Allocated 2014-01-31
020 31020000 – 020 31029999 GTT-EMEA LTD Allocated 2021-10-14
020 31030000 – 020 31039999 Colt Technology Services Allocated 2005-06-20
020 31040000 – 020 31049999 Alphatalk Limited Allocated 2014-01-31
020 31050000 – 020 31059999 TalkTalk Communications Limited Allocated 2015-01-06
020 31060000 – 020 31069999 Alphatalk Limited Allocated 2014-01-31
020 31070000 – 020 31079999 Verizon UK Limited Allocated 2005-06-28
020 31080000 – 020 31089999 Virgin Media Limited Allocated 2016-03-18
020 31090000 – 020 31099999 Commi Holdings Limited Allocated 2016-11-21
020 31100000 – 020 31109999 BT Allocated 2005-06-16
020 31110000 – 020 31119999 Served Up Limited Allocated 2008-06-03
020 31120000 – 020 31129999 BT Allocated 2005-06-17

900 more ranges — full list in CSV.

0203 allocation

Blocks whose local number starts with 3 under London (020): 9,210,000 allocated numbers in 921 blocks.

Allocated
9,210,000 numbers · 921 blocks
Protected
730,000 numbers · 73 blocks
Quarantined
60,000 numbers · 6 blocks

Holders of 020 3 numbers

BT holds 26.8% of the allocated numbers (2,300,000 numbers, 230 blocks).

Listed holders of 020 3 by share of allocated numbers · 14 Oct 2026
HolderShareNumbersBlocksEarliest allocation
BT26.8%2,300,0002302005-06-16
Gamma Telecom Holdings Limited15.0%1,380,0001382005-06-28
Colt Technology Services8.4%770,000772005-06-20
Sky UK Limited6.1%560,000562013-06-05
Verizon UK Limited4.6%420,000422005-06-28
Vodafone Ltd (C&W)4.0%370,000372013-06-20
TalkTalk Communications Limited3.4%310,000312007-08-08
Magrathea Telecommunications Limited1.8%170,000172007-01-26
GCI Network Solutions Limited1.2%110,000112017-03-30
Resilient Limited1.2%110,000112006-05-31
Virgin Media Limited1.2%110,000112006-06-02
Lumen Technologies UK Limited1.0%90,00092006-01-09
Voxbone SA1.0%90,00092007-10-25
Six Degrees Technology Group Limited0.9%80,00082020-04-08
Hyperoptic Ltd0.5%50,00052016-05-12
Vonage Business Limited0.5%50,00052010-04-20
AQL Wholesale Ltd0.4%40,00042006-07-06
Alphatalk Limited0.4%40,00042014-01-31
Cloudcall Limited0.4%40,00042011-06-21
Datazero Ltd0.4%40,00042010-11-02
Nuso Cloud UK Limited0.4%40,00042008-02-15
Voiceflex Limited0.4%40,00042007-07-24
Citrus Telecommunications Ltd0.3%30,00032005-08-09
DIDWW Ireland Limited0.3%30,00032014-04-07
Digital Space Group Limited0.3%30,00032006-02-07
Essensys (UK) Limited0.3%30,00032013-10-24
Fuse 2 Communications Ltd0.3%30,00032024-01-22
GTT-EMEA LTD0.3%30,00032021-10-14
Inet Telecoms Ltd (Voipfone)0.3%30,00032008-07-11
Pure-IP Limited0.3%30,00032017-01-24
Spitfire Network Services Limited0.3%30,00032005-07-01
Swiftnet Limited0.3%30,00032007-11-05
Telappliant Limited0.3%30,00032008-04-09
Telecom2 Limited0.3%30,00032009-09-01
The Excell Group Limited0.3%30,00032006-09-28
VoIP-Un Limited0.3%30,00032007-10-24
24 Seven Cloud Communications Ltd0.2%20,00022019-09-13
Barritec Limited0.2%20,00022011-09-05
Bicom Systems EURL0.2%20,00022008-07-24
Buzz Networks Limited0.2%20,00022010-02-24
Calltracks Limited0.2%20,00022013-09-20
Ccpro Solutions Limited0.2%20,00022009-06-03
Content Guru Limited0.2%20,00022007-11-21
Core Telecom Limited0.2%20,00022010-04-27
Mintaka Limited0.2%20,00022010-03-05
Nexbridge Communications Limited0.2%20,00022012-01-09
Nexus Telecommunications Limited0.2%20,00022007-07-05
Node4 Ltd0.2%20,00022011-05-25
Orbtalk Limited0.2%20,00022011-04-08
Premier Voicemail Ltd0.2%20,00022005-11-16
Redcentric Solutions Limited0.2%20,00022015-06-05
Served Up Limited0.2%20,00022008-06-03
Syntec Limited0.2%20,00022005-06-30
TGL Services (UK) Ltd0.2%20,00022015-02-02
TTNC Limited0.2%20,00022013-11-14
TelNG Limited0.2%20,00022007-03-01
TeleWare Group Limited0.2%20,00022013-02-20
VoiceHost Limited0.2%20,00022010-06-22
WAVECREST NETWORKS LIMITED0.2%20,00022019-12-16
X-on Health Limited0.2%20,00022009-11-19
Ziron Limited0.2%20,00022012-08-07
(AQ) LIMITED0.1%10,00012012-10-09
4D Interactive Ltd0.1%10,00012007-01-17
8x8 Communications UK Limited0.1%10,00012012-08-01
8x8 UK Limited0.1%10,00012009-12-11
Aloha Telecommunications Ltd0.1%10,00012011-08-04
Andrews & Arnold (Numbers) Ltd0.1%10,00012009-02-26
Andrews & Arnold Ltd0.1%10,00012006-10-13
Annecto Telecom0.1%10,00012017-05-11
Atlas Interactive Group Limited0.1%10,00012005-10-28
Atomstream Limited0.1%10,00012010-02-22
Barritel Limited0.1%10,00012006-02-13
Belgacom International Carrier Services SA0.1%10,00012016-06-20
CALLABLE LIMITED0.1%10,00012024-01-19
CFL Communications Ltd0.1%10,00012008-08-11
CINOS LIMITED0.1%10,00012022-03-24
Callitech Limited0.1%10,00012017-09-20
Commi Holdings Limited0.1%10,00012016-11-21
Connect Telecom UK Limited0.1%10,00012009-01-16
Convergence Group (wireless) Networks Limited0.1%10,00012013-01-07
DRD Communications Limited0.1%10,00012023-10-05
Dial 9 Communications Limited0.1%10,00012016-05-17
Digital Mail Limited0.1%10,00012005-06-07
Digitech Solutions Global Limited0.1%10,00012010-03-17
Dynamic Mobile Billing Limited0.1%10,00012009-04-09
ETC Telecom Limited0.1%10,00012008-02-06
EVE CONNECT LTD0.1%10,00012022-11-09
Entanet International Ltd0.1%10,00012007-12-20
Exa Networks Limited0.1%10,00012008-07-03
Firstcom Europe Limited0.1%10,00012023-12-04
Firstsound Ltd0.1%10,00012011-04-11
Fluency Communications Ltd0.1%10,00012013-10-07
Global Reach Networks Limited0.1%10,00012016-08-24
Group 3 Technology Limited0.1%10,00012011-04-06
HAVENSTOKE COMMUNICATIONS LTD0.1%10,00012026-03-17
Hello Telecom (UK) Limited0.1%10,00012009-04-24
ICC Networks Ltd0.1%10,00012010-03-10
ICUK Computing Services Limited0.1%10,00012019-08-12
IM Software Ltd0.1%10,00012012-03-20
INTELLIGENT EXCHANGES LIMITED0.1%10,00012026-01-26
INTERCITY TECHNOLOGY LIMITED0.1%10,00012017-02-24
IOVOX Limited0.1%10,00012012-03-05
IV Response Limited0.1%10,00012007-08-30
InTouch Communication Services Limited0.1%10,00012006-02-13
Infinity Tracking Ltd0.1%10,00012018-11-20
Internet of Things Limited0.1%10,00012018-08-13
Internetty Ltd0.1%10,00012019-04-01
Internexus Networks Limited0.1%10,00012011-11-22
Invade International Ltd0.1%10,00012016-01-12
Invosys Limited0.1%10,00012012-05-17
Jtec UK Limited0.1%10,00012011-07-26
KERV EXPERIENCE LIMITED0.1%10,00012014-07-28
Kalnet4U Ltd0.1%10,00012011-12-01
Lanonyx Telecom Limited0.1%10,00012011-08-22
Linear Telecoms Limited0.1%10,00012010-12-03
Liquid 11 Limited0.1%10,00012017-08-31
Localphone Limited0.1%10,00012007-05-22
London Central Communications Ltd0.1%10,00012006-12-11
Lycatel (Ireland) Limited0.1%10,00012006-03-01
Mars Communications Limited0.1%10,00012009-02-03
Media Hawk Ltd0.1%10,00012011-09-26
Mi Telecom Limited0.1%10,00012014-01-23
Microtalk Europe Limited0.1%10,00012016-03-17
Minotaur Telecom Limited0.1%10,00012013-01-31
Nationwide Telephone Assistance Ltd0.1%10,00012005-09-02
Nectar Cloud Ltd0.1%10,00012016-02-22
Need More Time Ltd0.1%10,00012007-07-17
Net-Work Internet Ltd0.1%10,00012007-09-21
Neutrino Networks Limited0.1%10,00012013-11-25
New Call Telecom Limited0.1%10,00012015-02-18
Nextec UK Limited0.1%10,00012013-12-06
Nodemax Limited0.1%10,00012008-07-17
Number Services Ltd.0.1%10,00012018-11-22
OME LOGIC LTD0.1%10,00012025-05-06
OVH Limited0.1%10,00012009-07-17
PCI-PAL (UK) Limited0.1%10,00012017-02-07
Phone Co-Op Numbering Limited0.1%10,00012010-11-29
Pulsant (Scotland) Limited0.1%10,00012009-02-17
Reality Network Services Limited0.1%10,00012007-12-03
Red Matter Limited0.1%10,00012010-04-30
Redwood Technologies Ltd0.1%10,00012018-11-15
RingGo Limited0.1%10,00012006-06-14
Simple Call Limited0.1%10,00012022-05-20
Simwood eSMS Limited0.1%10,00012006-07-18
Sipcentric Ltd0.1%10,00012014-06-30
Solutios Limited0.1%10,00012008-08-15
Sound Advertising Ltd0.1%10,00012007-10-31
Square 1 Communications Limited0.1%10,00012014-09-03
Square Systems Limited0.1%10,00012006-09-06
Stour Marine Limited0.1%10,00012014-04-01
Supported Business Limited0.1%10,00012016-06-21
Suretec Systems Ltd0.1%10,00012010-05-14
TAP GATEWAY LTD0.1%10,00012020-07-02
TP GLOBAL OPERATIONS LIMITED0.1%10,00012023-07-26
Tango Networks UK Ltd0.1%10,00012016-03-21
TelXL Limited0.1%10,00012008-02-12
TeleSurf Limited0.1%10,00012009-11-18
Telecoms World Limited0.1%10,00012009-07-02
Telefonica UK Limited0.1%10,00012010-04-16
Telemix Limited0.1%10,00012015-02-26
Telephone Box Limited0.1%10,00012010-10-27
Tismi BV0.1%10,00012011-01-26
Tuxtel Ltd0.1%10,00012015-09-03
VTSL Ltd0.1%10,00012015-11-06
Voicetec Systems Ltd0.1%10,00012006-06-22
Wifinity Limited0.1%10,00012009-02-20
WightFibre Limited0.1%10,00012009-11-09
Wordwatch Limited0.1%10,00012015-12-14
Zestel Limited0.1%10,00012013-02-19

Weekly changes for 0203

0 block changes from 19 Aug 2026 to 17 Oct 2026. Each week counts a block once.

0203 weekly changes since 19 Aug 2026
FromToChanged blocks
2026-08-192026-08-260
2026-08-262026-09-020
2026-09-022026-09-090
2026-09-092026-09-160
2026-09-162026-09-240
2026-09-242026-09-300
2026-09-302026-10-070
2026-10-072026-10-170

These numbers belong to 020 London. Methodology.

0203 source: Ofcom s1.csv, published 14 Oct 2026. Download 020 3 blocks (CSV). Contains Ofcom copyright material.

Source detail · 0203
0203 claim identifiers · release fc227d9e
ClaimValueIdentifier
allocated_numbers9210000subcode:020-3:allocated_numbers:fc227d9e:v1
allocated_records921subcode:020-3:allocated_records:fc227d9e:v1
listed_holders169subcode:020-3:listed_holders:fc227d9e:v1
area_code020subcode:020-3:area_code:fc227d9e:v1
first_digit3subcode:020-3:first_digit:fc227d9e:v1
snapshot_date14 Oct 2026subcode:020-3:snapshot_date:fc227d9e:v1