0800 Numbers
0800 numbers are a type of non-geographic number where only the receiver is charged for the call, but not the caller. 0800 numbers are not linked to any locale, which is why many businesses purchase these numbers for customer service use. These toll-free numbers are great marketing and customer service tools that allow businesses to achieve a higher reach at a lower cost to their customers.
Consumers consider 0800 numbers trustworthy, which means they are more likely to answer the phone when they receive a call from an 0800 number. Having an 0800 number also allows businesses to market their services outside of their vicinity. This is because 0800 are tied to a national presence, which makes them particularly useful for companies with multiple locations or for online businesses that distribute products nationally or internationally.
Before the introduction of the 0800 number in 1985, people would call the operator and ask for a company by name. While 0800 numbers were originally assigned to British Telecom, in 1994 ‘0800’ numbers were made available to other phone companies and three years later 0808 prefixes were also added to provide more freephone capacity.
Costs to call 0800 numbers
All 0800 numbers have always been free to call from landlines. The company receiving the call picks up the cost of the redirected call. Since 2015, mobile numbers have also ben free to call from mobile phones. This applies to any mobile network operator and no charges should be applied against your bill, or they can be disputed.
Prefixes and Providers
| Code | Provider | Assigned |
|---|
| Loading data… |
| 0800 001 4 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 001 5 | Vodafone Ltd (Thus) | 10/02/2012 |
| 0800 001 6 | Phone Buddy Limited | 15/07/2003 |
| 0800 002 5 | Phone Buddy Limited | 15/07/2003 |
| 0800 002 6 | Daotec Ltd | 27/04/2005 |
| 0800 002 9 | Core Telecom Limited | 01/03/2006 |
| 0800 003 2 | Icron Network Limited | 08/08/2006 |
| 0800 003 6 | CFL Communications Ltd | 28/03/2006 |
| 0800 004 2 | GCI Network Solutions Ltd | 19/04/2017 |
| 0800 004 7 | A2B Telecom Limited | 19/10/2011 |
| 0800 005 1 | Buzz Networks Limited | 07/07/2006 |
| 0800 005 2 | Buzz Networks Limited | 07/07/2006 |
| 0800 005 3 | Buzz Networks Limited | 07/07/2006 |
| 0800 005 4 | Rojo Trading Limited | 19/04/2007 |
| 0800 005 9 | Alnitak GmbH | 17/02/2015 |
| 0800 006 1 | Localphone Limited | 22/06/2007 |
| 0800 006 2 | Bicom Systems EURL | 23/07/2008 |
| 0800 006 4 | Jtec UK Limited | 26/07/2011 |
| 0800 006 7 | UK Number Store Limited | 16/03/2015 |
| 0800 007 3 | Simwood eSMS Limited | 13/07/2006 |
| 0800 007 4 | Gamma Telecom Holdings Ltd | 29/05/2013 |
| 0800 007 5 | Alphatalk Limited | 05/10/2004 |
| 0800 007 6 | Alphatalk Limited | 05/10/2004 |
| 0800 008 1 | Transaction Network Services (UK) Limited | 23/04/2019 |
| 0800 008 3 | Vodafone Ltd (Energis) | 06/02/2012 |
| 0800 008 6 | Gamma Telecom Holdings Ltd | 01/07/2005 |
| 0800 008 7 | Gamma Telecom Holdings Ltd | 07/02/2006 |
| 0800 009 1 | QX Telecom Ltd | 25/06/2007 |
| 0800 009 2 | Voiceflex Limited | 08/10/2007 |
| 0800 009 3 | Vodafone Ltd (Energis) | 18/01/2008 |
| 0800 009 4 | Vodafone Ltd (Energis) | 18/01/2008 |
| 0800 009 6 | Liquid 11 Limited | 16/12/2008 |
| 0800 009 8 | Gamma Telecom Holdings Ltd | 23/03/2021 |
| 0800 010 6 | Vodafone Ltd (C&W) | 18/06/2013 |
| 0800 011 1 | Elitetele.com plc | 27/03/2003 |
| 0800 011 2 | Digital Mail Limited | 14/08/2003 |
| 0800 011 3 | BT | 28/06/2005 |
| 0800 011 4 | TelXL Ltd | 29/06/2006 |
| 0800 011 6 | BT | 08/09/2009 |
| 0800 011 7 | Vectone Mobile Limited | 08/07/2009 |
| 0800 011 8 | The Number UK Limited | 04/05/2004 |
| 0800 011 9 | (AQ) LIMITED | 28/09/2012 |
| 0800 012 0 | Lycatel (Ireland) Limited | 01/03/2006 |
| 0800 012 1 | BT | 03/11/2004 |
| 0800 012 2 | Invade International Ltd | 13/01/2016 |
| 0800 012 4 | Telappliant Ltd | 09/04/2008 |
| 0800 012 5 | Calltracks Limited | 29/07/2013 |
| 0800 012 6 | Vodafone Ltd (Energis) | 18/01/2008 |
| 0800 012 8 | Six Degrees Technology Group Limited | 16/09/2020 |
| 0800 012 9 | DRD Communications Limited | 11/09/2009 |
| 0800 013 | Virgin Media Limited | 23/05/2002 |
| 0800 014 1 | Vodafone Ltd (Thus) | 10/02/2012 |
| 0800 014 2 | TalkTalk Communications Limited | 23/04/2012 |
| 0800 014 4 | Cloud9 Communications Limited | 23/04/2010 |
| 0800 014 5 | Wavenet UK Ltd | 17/12/2010 |
| 0800 014 6 | Numbers Plus Ltd | 20/07/2011 |
| 0800 014 7 | Gamma Telecom Holdings Ltd | 09/04/2009 |
| 0800 014 8 | Voxbone SA | 10/07/2009 |
| 0800 014 9 | Invosys Limited | 28/06/2012 |
| 0800 015 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 016 1 | Real Telekom Ltd | 31/01/2011 |
| 0800 016 3 | BT | 29/10/2012 |
| 0800 016 5 | Verizon UK Limited | 11/06/2001 |
| 0800 016 7 | Real Telekom Ltd | 31/01/2011 |
| 0800 016 8 | Zamir Telecom Limited | 23/02/2011 |
| 0800 016 9 | Nexus Telecommunications Limited | 30/04/2013 |
| 0800 018 | Verizon UK Limited | 08/09/1995 |
| 0800 019 | TalkTalk Communications Limited | 29/06/2006 |
| 0800 020 5 | Park Now Limited | 11/07/2008 |
| 0800 020 6 | Need More Time Ltd | 09/07/2008 |
| 0800 020 9 | BT | 02/06/2011 |
| 0800 021 0 | NBCN Networks Ltd | 07/01/2010 |
| 0800 021 1 | Mintaka Limited | 05/03/2010 |
| 0800 021 2 | GCI Network Solutions Ltd | 19/04/2017 |
| 0800 021 3 | Daisy Communications Ltd | 21/12/2010 |
| 0800 021 4 | TalkTalk Communications Limited | 29/06/2006 |
| 0800 021 5 | Telecom Express Limited | 23/06/2011 |
| 0800 021 6 | Node4 Ltd | 02/11/2012 |
| 0800 021 7 | TalkTalk Communications Limited | 29/06/2006 |
| 0800 021 8 | BCH Digital Limited | 26/10/2010 |
| 0800 021 9 | Planet Numbers Ltd | 10/10/2011 |
| 0800 022 1 | 24 SEVEN CLOUD COMMUNICATIONS LTD | 07/10/2019 |
| 0800 022 3 | BT | 15/06/2005 |
| 0800 022 4 | BT | 28/06/2005 |
| 0800 022 6 | Barritec Limited | 31/10/2012 |
| 0800 022 9 | Via-Vox Limited | 27/10/2008 |
| 0800 023 1 | Maximus Communications Ltd | 15/09/2004 |
| 0800 023 2 | BT | 28/06/2005 |
| 0800 023 3 | Nodemax Limited | 04/06/2015 |
| 0800 023 4 | BT | 03/11/2004 |
| 0800 023 5 | BT | 10/10/2011 |
| 0800 023 6 | BT | 10/10/2011 |
| 0800 023 7 | TalkTalk Communications Limited | 29/06/2006 |
| 0800 023 8 | BT | 01/05/2012 |
| 0800 023 9 | Telappliant Ltd | 16/04/2013 |
| 0800 024 1 | Affiniti Integrated Solutions Limited | 07/04/2004 |
| 0800 024 2 | Vodafone Ltd (Thus) | 10/02/2012 |
| 0800 024 3 | Aloha Telecommunications Ltd | 06/08/2012 |
| 0800 024 4 | C2C Limited | 07/10/2003 |
| 0800 024 5 | Atomstream Limited | 30/03/2011 |
| 0800 024 6 | BT | 29/10/2012 |
| 0800 024 7 | 24 SEVEN CLOUD COMMUNICATIONS LTD | 07/10/2019 |
| 0800 024 8 | BT | 01/05/2012 |
| 0800 024 9 | Intrado Cloud Solutions Limited | 27/08/2013 |
| 0800 025 3 | TeleWare Group PLC | 20/02/2013 |
| 0800 025 5 | Nodemax Limited | 04/06/2015 |
| 0800 025 7 | IOVOX Limited | 28/01/2013 |
| 0800 025 8 | Digital Space Group Limited | 27/07/2005 |
| 0800 026 | Orange Business Holdings UK Limited | 26/02/2013 |
| 0800 027 | Vodafone Ltd (Thus) | 10/02/2012 |
| 0800 028 | BT | 08/12/1998 |
| 0800 029 1 | BT | 01/02/2016 |
| 0800 029 3 | BT | 01/02/2016 |
| 0800 029 4 | Vodafone Ltd (C&W) | 18/08/2015 |
| 0800 029 7 | Xoom Ltd | 21/11/2019 |
| 0800 029 8 | Via-Vox Limited | 09/05/2016 |
| 0800 030 2 | Talk Numbers Ltd | 09/06/2010 |
| 0800 030 4 | BT | 15/06/2005 |
| 0800 030 5 | Barritel Limited | 09/05/2005 |
| 0800 030 6 | Redwood Technologies Ltd | 15/11/2018 |
| 0800 030 7 | XoverX Ltd | 09/05/2013 |
| 0800 030 8 | Gamma Telecom Holdings Ltd | 19/06/2015 |
| 0800 030 9 | Redwood Technologies Ltd | 15/11/2018 |
| 0800 031 4 | BT | 14/03/2013 |
| 0800 031 5 | BT | 14/03/2013 |
| 0800 031 6 | TalkTalk Communications Limited | 10/03/2006 |
| 0800 031 7 | Pipex Communications PLC | 14/07/2000 |
| 0800 031 8 | Belgacom International Carrier Services SA | 20/06/2016 |
| 0800 031 9 | Dynamic Mobile Billing Limited | 12/10/2000 |
| 0800 032 | BT | 21/11/2001 |
| 0800 033 2 | Core Telecom Limited | 21/04/2016 |
| 0800 033 4 | Gamma Telecom Holdings Ltd | 25/03/2014 |
| 0800 033 6 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 033 7 | Inet Telecoms Ltd (Voipfone) | 14/08/2008 |
| 0800 033 8 | Hutchison 3G UK Ltd | 17/09/2007 |
| 0800 033 9 | IPV6 Limited | 19/01/2009 |
| 0800 034 | Inclarity Communications Limited | 23/01/2014 |
| 0800 035 | Daisy Communications Ltd | 21/12/2010 |
| 0800 036 | New Call Telecom Ltd | 12/12/2012 |
| 0800 037 | Buzz Networks Limited | 09/07/1998 |
| 0800 038 | Daisy Communications Ltd | 21/12/2010 |
| 0800 039 | Eircom (UK) Limited | 31/01/2000 |
| 0800 040 6 | Sala Trading Ltd | 17/01/2002 |
| 0800 040 7 | Vodafone Ltd (Thus) | 10/02/2012 |
| 0800 040 8 | Daisy Communications Ltd | 21/12/2010 |
| 0800 040 9 | Nodemax Limited | 04/06/2015 |
| 0800 041 1 | Telephone Box Limited | 18/11/2010 |
| 0800 041 3 | Node4 Ltd | 27/09/2010 |
| 0800 041 7 | Callitech Limited | 27/03/2017 |
| 0800 041 8 | Magrathea Telecommunications Limited | 20/03/2017 |
| 0800 041 9 | AQL Wholesale Ltd | 04/08/2015 |
| 0800 042 | TalkTalk Communications Limited | 27/09/2011 |
| 0800 043 | Telecoms World PLC | 20/03/2002 |
| 0800 044 1 | Square 1 Communications Limited | 02/09/2014 |
| 0800 044 3 | TelXL Ltd | 04/12/2009 |
| 0800 044 5 | TelXL Ltd | 24/11/2008 |
| 0800 044 8 | Affiniti Integrated Solutions Limited | 15/11/2012 |
| 0800 044 9 | IOVOX Limited | 27/01/2017 |
| 0800 046 0 | Third Party Formations Limited TA The Company Warehouse | 16/07/2012 |
| 0800 046 1 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 046 2 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 046 3 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 046 4 | Media Hawk Ltd | 26/09/2011 |
| 0800 046 5 | Magrathea Telecommunications Limited | 09/02/2016 |
| 0800 046 6 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 046 7 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 046 8 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 046 9 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 047 0 | Magrathea Telecommunications Limited | 01/07/2005 |
| 0800 047 1 | I.T Communications Limited | 09/03/2015 |
| 0800 047 2 | BT | 16/11/2017 |
| 0800 047 3 | Infinity Tracking Ltd | 20/11/2018 |
| 0800 047 4 | Barritel Limited | 09/05/2005 |
| 0800 047 5 | IOVOX Limited | 09/10/2013 |
| 0800 047 6 | IOVOX Limited | 15/10/2013 |
| 0800 047 8 | BT | 03/01/2019 |
| 0800 048 0 | Vodafone Ltd (Energis) | 05/07/2007 |
| 0800 048 1 | Vodafone Ltd (Energis) | 05/07/2007 |
| 0800 048 2 | Vodafone Ltd (Energis) | 05/07/2007 |
| 0800 048 3 | Vodafone Ltd (Energis) | 05/07/2007 |
| 0800 048 4 | Vodafone Ltd (Energis) | 05/07/2007 |
| 0800 048 5 | Magrathea Telecommunications Limited | 19/02/2019 |
| 0800 048 6 | Affiniti Integrated Solutions Limited | 06/08/2015 |
| 0800 048 7 | BT | 26/03/2019 |
| 0800 048 8 | Voxbone SA | 28/12/2007 |
| 0800 048 9 | BT | 26/03/2019 |
| 0800 049 | TalkTalk Communications Limited | 30/05/2007 |
| 0800 050 0 | Icron Network Limited | 08/08/2006 |
| 0800 050 1 | Redcentric Solutions Limited | 25/05/2016 |
| 0800 050 2 | Budget Numbers Limited | 26/04/2007 |
| 0800 050 9 | IOVOX Limited | 15/08/2012 |
| 0800 051 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 052 | Virgin Media Limited | 30/06/1998 |
| 0800 053 | Sky UK Limited | 11/12/2013 |
| 0800 054 0 | iHub 2 Limited | 17/06/2016 |
| 0800 054 1 | BT | 24/06/2020 |
| 0800 054 2 | Gamma Telecom Holdings Ltd | 28/09/2009 |
| 0800 054 5 | Resilient PLC | 22/02/2008 |
| 0800 054 6 | Gamma Telecom Holdings Ltd | 28/09/2009 |
| 0800 054 7 | Odigo | 16/03/2020 |
| 0800 054 8 | Magrathea Telecommunications Limited | 12/01/2021 |
| 0800 054 9 | IOVOX Limited | 12/02/2018 |
| 0800 055 3 | Pulsant (Scotland) Limited | 20/02/2009 |
| 0800 055 4 | TELNYX UK LIMITED | 28/04/2020 |
| 0800 055 6 | BT | 28/06/2005 |
| 0800 055 7 | Telecom2 Limited | 16/09/2014 |
| 0800 056 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 058 0 | Subtopia Limited | 28/07/2015 |
| 0800 058 2 | Vodafone Ltd (Energis) | 30/05/2006 |
| 0800 058 8 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 059 0 | Voiceflex Limited | 01/06/2017 |
| 0800 059 5 | Voice Simplified Limited | 25/06/2013 |
| 0800 059 9 | Telecoms World PLC | 01/05/2008 |
| 0800 060 1 | Axe Telecom Limited | 26/02/2018 |
| 0800 060 7 | Daisy Communications Ltd | 21/12/2010 |
| 0800 060 8 | Voxbone SA | 11/01/2017 |
| 0800 061 0 | UK BANDWIDTH LIMITED | 11/09/2019 |
| 0800 061 1 | 24 SEVEN CLOUD COMMUNICATIONS LTD | 07/10/2019 |
| 0800 061 2 | GCI Network Solutions Ltd | 19/04/2017 |
| 0800 061 3 | Idt Global Ltd | 21/08/2000 |
| 0800 061 4 | Kalnet4U Ltd | 04/01/2016 |
| 0800 062 2 | Affiniti Integrated Solutions Limited | 11/03/2016 |
| 0800 062 3 | 24 SEVEN CLOUD COMMUNICATIONS LTD | 07/10/2019 |
| 0800 062 7 | ATH LTD | 09/03/2017 |
| 0800 063 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 064 | Virgin Media Limited | 23/05/2002 |
| 0800 065 0 | Public Internet Limited | 27/05/2020 |
| 0800 065 4 | Budget Numbers Limited | 05/08/2015 |
| 0800 066 2 | Magrathea Telecommunications Limited | 08/11/2002 |
| 0800 066 3 | Magrathea Telecommunications Limited | 09/06/2010 |
| 0800 066 4 | Magrathea Telecommunications Limited | 28/12/2001 |
| 0800 066 5 | BT | 15/06/2005 |
| 0800 066 8 | Belgacom International Carrier Services SA | 02/03/2021 |
| 0800 066 9 | Vodafone Ltd (C&W) | 06/05/2014 |
| 0800 067 | Adviqo UK Limited | 12/06/2012 |
| 0800 068 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 069 6 | Gamma Telecom Holdings Ltd | 11/11/2008 |
| 0800 069 8 | Voxbone SA | 02/08/2016 |
| 0800 069 9 | Telecoms World PLC | 07/12/2007 |
| 0800 070 1 | Opex Hosting Limited | 21/07/2008 |
| 0800 070 5 | Aloha Telecommunications Ltd | 10/08/2015 |
| 0800 070 6 | Transaction Network Services (UK) Limited | 17/06/2020 |
| 0800 071 | Spacetel UK Ltd | 28/02/1996 |
| 0800 072 | Vodafone Ltd (Energis) | 30/05/2006 |
| 0800 073 | Virgin Media Limited | 08/04/2016 |
| 0800 074 | Vodafone Ltd (Thus) | 10/02/2012 |
| 0800 075 | 4D INTERACTIVE LTD | 03/06/1998 |
| 0800 077 1 | Digitech Solutions Global Limited | 07/05/2008 |
| 0800 077 3 | Magrathea Telecommunications Limited | 16/10/2009 |
| 0800 077 4 | Magrathea Telecommunications Limited | 22/07/2010 |
| 0800 077 5 | Alphatalk Limited | 02/07/2008 |
| 0800 077 6 | TelXL Ltd | 30/01/2002 |
| 0800 077 8 | BT | 15/06/2005 |
| 0800 077 9 | 001 International Telecom | 19/10/2011 |
| 0800 078 1 | Newtel Limited | 16/04/2003 |
| 0800 078 3 | Magrathea Telecommunications Limited | 22/07/2010 |
| 0800 078 6 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 078 7 | GCI Network Solutions Ltd | 19/04/2017 |
| 0800 078 9 | Commi Holdings Limited | 16/11/2016 |
| 0800 079 | EE Limited (Orange) | 17/07/1997 |
| 0800 080 3 | VoIP-Un Limited | 09/11/2007 |
| 0800 080 5 | GCI Network Solutions Ltd | 19/04/2017 |
| 0800 080 6 | Vodafone Ltd (C&W) | 18/06/2013 |
| 0800 080 7 | Vodafone Ltd (C&W) | 18/06/2013 |
| 0800 081 | GCI Network Solutions Ltd | 19/04/2017 |
| 0800 082 | Six Degrees Technology Group Limited | 16/09/2020 |
| 0800 083 | TalkTalk Communications Limited | 09/10/2003 |
| 0800 084 1 | Magrathea Telecommunications Limited | 22/07/2010 |
| 0800 084 2 | Vodafone Ltd (Thus) | 15/02/2012 |
| 0800 084 3 | Magrathea Telecommunications Limited | 19/04/2011 |
| 0800 084 4 | TalkTalk Communications Limited | 14/10/2013 |
| 0800 084 5 | Barritel Limited | 09/05/2005 |
| 0800 084 6 | Magrathea Telecommunications Limited | 22/07/2010 |
| 0800 084 8 | Barritel Limited | 09/05/2005 |
| 0800 085 | BT | 22/03/2000 |
| 0800 086 1 | Magrathea Telecommunications Limited | 22/07/2010 |
| 0800 086 2 | Invoco Ltd | 17/10/2011 |
| 0800 086 8 | Voxbone SA | 27/09/2011 |
| 0800 086 9 | Voxbone SA | 06/11/2014 |
| 0800 087 6 | Nexbridge Communications Limited | 07/07/2021 |
| 0800 088 2 | API Telecom Limited | 01/08/2012 |
| 0800 088 3 | Storacall Technology Limited | 19/11/2009 |
| 0800 088 4 | Gamma Telecom Holdings Ltd | 19/06/2008 |
| 0800 088 5 | Voxbone SA | 24/03/2011 |
| 0800 088 6 | Planet Numbers Ltd | 03/06/2009 |
| 0800 088 7 | TelXL Ltd | 30/01/2002 |
| 0800 089 | GCI Network Solutions Ltd | 19/04/2017 |
| 0800 090 1 | TalkTalk Communications Limited | 02/02/2007 |
| 0800 090 2 | Telefonica UK Limited | 08/11/2010 |
| 0800 090 3 | Magrathea Telecommunications Limited | 05/04/2013 |
| 0800 090 5 | Media Telecom Ltd | 20/01/2011 |
| 0800 090 8 | Neutrino Networks Limited | 19/12/2018 |
| 0800 091 | Syntec Limited | 02/11/1999 |
| 0800 092 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 093 | TalkTalk Communications Limited | 09/10/2003 |
| 0800 094 0 | Sigma Voice Solutions Ltd | 31/12/2007 |
| 0800 094 9 | Invade International Ltd | 13/01/2016 |
| 0800 096 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 097 | WAVECREST NETWORKS LIMITED | 16/12/2019 |
| 0800 098 0 | 24 SEVEN CLOUD COMMUNICATIONS LTD | 07/10/2019 |
| 0800 098 7 | Nexbridge Communications Limited | 10/01/2012 |
| 0800 098 8 | Voxbone SA | 11/05/2009 |
| 0800 099 1 | Fuse 2 Communications Ltd | 11/05/2021 |
| 0800 099 5 | Fido Telecom Limited | 19/05/2015 |
| 0800 099 6 | Telecoms World Direct Ltd | 12/06/2014 |
| 0800 099 7 | Twelve Telecom Limited | 25/04/2013 |
| 0800 099 8 | Digital Select Limited | 05/03/2013 |
| 0800 101 3 | Alphatalk Limited | 30/01/2014 |
| 0800 101 5 | Inclarity Communications Limited | 23/01/2014 |
| 0800 101 7 | Orbtalk Limited | 10/05/2011 |
| 0800 101 8 | TalkTalk Communications Limited | 01/05/2014 |
| 0800 102 5 | TalkTalk Communications Limited | 27/07/2012 |
| 0800 102 6 | DIDWW Ireland Limited | 10/02/2021 |
| 0800 103 2 | Invosys Limited | 15/08/2012 |
| 0800 107 | Vodafone Ltd (Energis) | 30/05/2006 |
| 0800 108 1 | Gencom Technologies Ltd | 16/06/2016 |
| 0800 108 8 | Invade International Ltd | 13/01/2016 |
| 0800 110 2 | Daisy Communications Ltd | 21/12/2010 |
| 0800 110 3 | Daisy Communications Ltd | 21/12/2010 |
| 0800 110 5 | TalkTalk Communications Limited | 25/01/2008 |
| 0800 110 6 | Daisy Communications Ltd | 21/12/2010 |
| 0800 111 1 | BT | 26/01/2004 |
| 0800 111 4 | BT | 15/06/2005 |
| 0800 111 6 | TalkTalk Communications Limited | 13/08/2004 |
| 0800 112 0 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 112 3 | Telecoms World PLC | 06/02/2007 |
| 0800 112 4 | Call Stream Limited | 21/12/2005 |
| 0800 112 5 | Liquid 11 Limited | 21/12/2020 |
| 0800 112 6 | Andrews & Arnold (Numbers) Ltd | 18/05/2010 |
| 0800 114 3 | Calltracks Limited | 29/07/2013 |
| 0800 116 4 | TalkTalk Communications Limited | 02/02/2007 |
| 0800 117 0 | I-NET COMMUNICATIONS GROUP PLC | 25/06/2015 |
| 0800 118 0 | Digital Mail Limited | 29/06/2005 |
| 0800 118 1 | Affiniti Integrated Solutions Limited | 16/11/2005 |
| 0800 118 2 | TTNC Limited | 02/10/2013 |
| 0800 118 4 | Six Degrees Technology Group Limited | 16/09/2020 |
| 0800 118 5 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 118 6 | ATH LTD | 09/03/2017 |
| 0800 118 9 | ATH LTD | 09/03/2017 |
| 0800 121 4 | BT | 29/03/2006 |
| 0800 121 6 | BT | 29/03/2006 |
| 0800 121 7 | BT | 29/03/2006 |
| 0800 121 8 | BT | 03/11/2004 |
| 0800 122 3 | IM Software Ltd | 28/05/2009 |
| 0800 124 4 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 129 9 | Telecoms World Direct Ltd | 12/06/2014 |
| 0800 130 0 | TalkTalk Communications Limited | 20/02/2006 |
| 0800 130 3 | Windsor Telecom Ltd | 13/06/2011 |
| 0800 131 0 | Cloudcall Limited | 15/06/2011 |
| 0800 131 3 | TalkTalk Communications Limited | 06/04/2005 |
| 0800 133 1 | HighSpeed Office Limited | 26/04/2004 |
| 0800 133 7 | Inet Telecoms Ltd (Voipfone) | 29/10/2012 |
| 0800 133 8 | Premier Voicemail Ltd | 31/10/2014 |
| 0800 135 7 | TTNC Limited | 02/10/2013 |
| 0800 138 | Affiniti Integrated Solutions Limited | 14/09/1995 |
| 0800 139 | Virgin Media Limited | 10/09/1997 |
| 0800 140 4 | Affiniti Integrated Solutions Limited | 12/10/2010 |
| 0800 140 9 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 141 2 | BT | 29/03/2006 |
| 0800 141 3 | Vodafone Ltd (C&W) | 02/08/2013 |
| 0800 142 2 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 142 5 | GCI Network Solutions Ltd | 19/04/2017 |
| 0800 144 4 | TalkTalk Communications Limited | 13/08/2004 |
| 0800 144 5 | I-NET COMMUNICATIONS GROUP PLC | 25/06/2015 |
| 0800 144 8 | Affiniti Integrated Solutions Limited | 24/09/2013 |
| 0800 145 5 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 145 6 | BT | 28/06/2005 |
| 0800 148 8 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 150 3 | Core Telecom Limited | 21/04/2016 |
| 0800 150 9 | Virgin Media Limited | 08/04/2016 |
| 0800 151 0 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 151 2 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 151 3 | BT | 29/03/2006 |
| 0800 152 2 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 152 5 | Affiniti Integrated Solutions Limited | 17/08/2020 |
| 0800 153 3 | I-NET COMMUNICATIONS GROUP PLC | 25/06/2015 |
| 0800 156 0 | Affiniti Integrated Solutions Limited | 31/03/2004 |
| 0800 157 1 | Buzz Networks Limited | 07/07/2006 |
| 0800 157 7 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 158 2 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 158 3 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 158 4 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 158 5 | Vodafone Ltd (C&W) | 12/09/2013 |
| 0800 158 8 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 160 1 | Admiral Telecom Limited | 11/08/2006 |
| 0800 161 3 | Vodafone Ltd (Thus) | 15/02/2012 |
| 0800 161 5 | Vodafone Ltd (C&W) | 02/08/2013 |
| 0800 161 7 | PlusNet PLC | 21/09/2005 |
| 0800 164 | Swiftnet Ltd | 13/08/2001 |
| 0800 167 0 | Daisy Communications Ltd | 21/12/2010 |
| 0800 169 | BT | 10/06/1999 |
| 0800 170 0 | Nationwide Telephone Assistance Ltd | 02/09/2005 |
| 0800 170 1 | Windsor Telecom Ltd | 13/06/2011 |
| 0800 170 7 | Floren Limited | 14/11/2014 |
| 0800 171 2 | BT | 29/03/2006 |
| 0800 177 7 | Windsor Telecom Ltd | 30/03/2011 |
| 0800 177 8 | I-NET COMMUNICATIONS GROUP PLC | 04/10/2016 |
| 0800 179 9 | Barritel Limited | 28/08/2009 |
| 0800 180 4 | Windsor Telecom Ltd | 24/01/2002 |
| 0800 180 8 | Real Time Telecoms Ltd | 21/08/2014 |
| 0800 181 4 | BT | 29/03/2006 |
| 0800 182 2 | Vodafone Ltd (C&W) | 18/02/2016 |
| 0800 183 | Virgin Media Limited | 04/11/1997 |
| 0800 185 0 | Vispa Limited | 13/05/2020 |
| 0800 185 5 | I-NET COMMUNICATIONS GROUP PLC | 04/10/2016 |
| 0800 188 0 | Connect Telecom UK Limited | 27/07/2001 |
| 0800 188 4 | Affiniti Integrated Solutions Limited | 15/11/2012 |
| 0800 191 0 | Premier Voicemail Ltd | 05/12/2001 |
| 0800 192 0 | PlusNet PLC | 21/09/2005 |
| 0800 193 0 | Telecoms World PLC | 04/11/2009 |
| 0800 193 1 | Telecoms World PLC | 04/11/2009 |
| 0800 193 2 | Telecoms World PLC | 04/11/2009 |
| 0800 193 3 | Telecoms World PLC | 04/11/2009 |
| 0800 193 4 | Telecoms World PLC | 04/11/2009 |
| 0800 193 5 | Telecoms World PLC | 04/11/2009 |
| 0800 193 6 | Telecoms World PLC | 04/11/2009 |
| 0800 193 7 | Telecoms World PLC | 04/11/2009 |
| 0800 193 8 | Telecoms World PLC | 04/11/2009 |
| 0800 193 9 | Telecoms World PLC | 04/11/2009 |
| 0800 195 | Vodafone Ltd (Thus) | 15/02/2012 |
| 0800 196 | Orange Business Holdings UK Limited | 26/02/2013 |
| 0800 197 | Vodafone Ltd (Energis) | 30/05/2006 |
| 0800 198 | GCI Network Solutions Ltd | 19/04/2017 |
| 0800 200 6 | Virgin Media Limited | 08/04/2016 |
| 0800 201 2 | Digital Mail Limited | 29/11/2005 |
| 0800 201 4 | I-NET COMMUNICATIONS GROUP PLC | 09/07/2010 |
| 0800 202 8 | BT | 06/04/2006 |
| 0800 204 4 | I-NET COMMUNICATIONS GROUP PLC | 25/06/2015 |
| 0800 205 5 | TelNG Limited | 24/01/2008 |
| 0800 205 6 | TelNG Limited | 18/03/2010 |
| 0800 206 1 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 206 2 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 209 9 | TelecomIQ Limited | 18/05/2015 |
| 0800 210 0 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 210 1 | 24 SEVEN CLOUD COMMUNICATIONS LTD | 07/10/2019 |
| 0800 211 8 | TTNC Limited | 02/10/2013 |
| 0800 215 5 | Nextec UK Limited | 26/11/2013 |
| 0800 216 3 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 218 2 | BT | 30/08/2005 |
| 0800 219 6 | Patoy Ltd | 16/08/2000 |
| 0800 221 8 | Call Stream Limited | 21/09/2005 |
| 0800 222 9 | Telecoms World PLC | 10/08/2010 |
| 0800 223 0 | Call Stream Limited | 21/12/2005 |
| 0800 224 8 | Barritel Limited | 09/05/2005 |
| 0800 227 0 | Linear Telecoms Limited | 23/04/2012 |
| 0800 228 9 | Core Telecom Limited | 03/05/2012 |
| 0800 229 0 | Via-Vox Limited | 22/12/2011 |
| 0800 229 1 | Via-Vox Limited | 17/12/2012 |
| 0800 229 4 | Via-Vox Limited | 21/11/2017 |
| 0800 230 0 | TalkTalk Communications Limited | 20/02/2006 |
| 0800 231 5 | TalkTalk Communications Limited | 20/07/2006 |
| 0800 231 6 | GCI Network Solutions Ltd | 19/04/2017 |
| 0800 232 1 | BT | 29/03/2006 |
| 0800 233 5 | Telecoms World PLC | 01/05/2008 |
| 0800 234 3 | TTNC Limited | 02/10/2013 |
| 0800 234 6 | BT | 03/11/2004 |
| 0800 240 4 | Affiniti Integrated Solutions Limited | 12/10/2010 |
| 0800 240 5 | Vocalis Telecom | 08/12/2001 |
| 0800 242 5 | BT | 15/02/2012 |
| 0800 246 1 | Kalnet4U Ltd | 25/07/2014 |
| 0800 246 5 | Kalnet4U Ltd | 24/03/2015 |
| 0800 246 6 | Internexus Networks Limited | 18/04/2013 |
| 0800 247 1 | TalkTalk Communications Limited | 19/01/2004 |
| 0800 249 4 | Citrus Telecommunications Ltd | 30/06/2006 |
| 0800 251 1 | I-NET COMMUNICATIONS GROUP PLC | 25/06/2015 |
| 0800 254 0 | Phone Co-Op Numbering Limited | 02/12/2010 |
| 0800 254 5 | VoiceHost Limited | 26/04/2012 |
| 0800 255 0 | Barritel Limited | 09/05/2005 |
| 0800 258 5 | Six Degrees Technology Group Limited | 16/09/2020 |
| 0800 260 0 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 260 5 | Colt Technology Services | 16/10/2013 |
| 0800 260 6 | Colt Technology Services | 06/09/2012 |
| 0800 270 0 | Suretec Systems Ltd | 02/06/2010 |
| 0800 270 7 | Core Telecom Limited | 20/02/2012 |
| 0800 273 5 | Verizon UK Limited | 01/10/2004 |
| 0800 275 1 | Ziron Limited | 02/08/2012 |
| 0800 276 1 | TalkTalk Communications Limited | 30/01/2009 |
| 0800 277 0 | PCI-PAL (UK) Limited | 31/01/2017 |
| 0800 279 | Verizon UK Limited | 24/07/1995 |
| 0800 280 0 | TalkTalk Communications Limited | 20/02/2006 |
| 0800 280 2 | Vodafone Ltd (Thus) | 15/02/2012 |
| 0800 280 8 | Affiniti Integrated Solutions Limited | 24/09/2013 |
| 0800 285 1 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 288 4 | Affiniti Integrated Solutions Limited | 06/08/2015 |
| 0800 288 8 | TalkTalk Communications Limited | 29/06/2006 |
| 0800 288 9 | TalkTalk Communications Limited | 06/04/2005 |
| 0800 292 2 | Telecoms World PLC | 07/12/2007 |
| 0800 292 6 | Dial 9 Communications Limited | 17/05/2016 |
| 0800 292 7 | Premier Voicemail Ltd | 27/10/2011 |
| 0800 294 | Vodafone Ltd (Energis) | 30/05/2006 |
| 0800 297 0 | WAVECREST NETWORKS LIMITED | 16/12/2019 |
| 0800 297 1 | WAVECREST NETWORKS LIMITED | 16/12/2019 |
| 0800 297 2 | WAVECREST NETWORKS LIMITED | 16/12/2019 |
| 0800 298 | TalkTalk Communications Limited | 15/10/2013 |
| 0800 302 9 | Vodafone Ltd (C&W) | 02/08/2013 |
| 0800 303 2 | Premier Voicemail Ltd | 14/04/2009 |
| 0800 304 7 | Club Communications Ltd | 01/07/2000 |
| 0800 307 0 | SiPalto Ltd | 09/07/2020 |
| 0800 307 7 | Cirrus Response Limited | 12/02/2014 |
| 0800 308 1 | TalkTalk Communications Limited | 02/02/2007 |
| 0800 310 0 | I-NET COMMUNICATIONS GROUP PLC | 03/11/2010 |
| 0800 310 1 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 310 2 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 311 2 | Commi Holdings Limited | 16/11/2016 |
| 0800 311 8 | TTNC Limited | 02/10/2013 |
| 0800 313 4 | BT | 29/03/2006 |
| 0800 313 5 | PEERLESS NETWORK UK LIMITED | 03/06/2019 |
| 0800 316 | Vodafone Ltd (Energis) | 30/05/2006 |
| 0800 319 6 | Spitfire Network Services Limited | 27/10/2000 |
| 0800 320 2 | Numbergroup Utilities Ltd | 11/07/2011 |
| 0800 321 3 | Vodafone Ltd (C&W) | 18/06/2013 |
| 0800 321 7 | Barritel Limited | 14/12/2001 |
| 0800 323 4 | BT | 29/03/2006 |
| 0800 324 7 | Commi Holdings Limited | 16/11/2016 |
| 0800 326 5 | Affiniti Integrated Solutions Limited | 16/01/2008 |
| 0800 327 7 | Magrathea Telecommunications Limited | 27/03/2008 |
| 0800 328 | BT | 26/02/1998 |
| 0800 330 2 | Numbers Telecom Limited | 12/07/2012 |
| 0800 330 6 | WIZE ANALYTICS LIMITED | 29/04/2019 |
| 0800 330 8 | Call Stream Limited | 21/12/2005 |
| 0800 331 0 | Sigma Voice Solutions Ltd | 31/12/2007 |
| 0800 331 6 | BT | 28/11/2007 |
| 0800 331 7 | Affiniti Integrated Solutions Limited | 16/01/2008 |
| 0800 334 5 | Telecoms World PLC | 07/12/2007 |
| 0800 335 7 | TTNC Limited | 02/10/2013 |
| 0800 338 1 | Media Hawk Ltd | 01/07/2020 |
| 0800 338 4 | FUSION TELECOM LTD | 14/05/2020 |
| 0800 342 3 | Vodafone Ltd (Thus) | 15/02/2012 |
| 0800 345 7 | BT | 03/11/2004 |
| 0800 355 | TalkTalk Communications Limited | 12/06/2006 |
| 0800 357 9 | TTNC Limited | 02/10/2013 |
| 0800 358 | Colt Technology Services | 17/01/1996 |
| 0800 360 0 | Orbtalk Limited | 17/07/2012 |
| 0800 361 | Transaction Network Services (UK) Limited | 28/02/2000 |
| 0800 362 1 | Colt Technology Services | 03/05/2019 |
| 0800 363 5 | BT | 29/03/2006 |
| 0800 368 0 | Colt Technology Services | 01/08/2007 |
| 0800 368 1 | Colt Technology Services | 06/08/2007 |
| 0800 368 2 | Colt Technology Services | 06/08/2007 |
| 0800 368 3 | Colt Technology Services | 06/08/2007 |
| 0800 368 4 | Colt Technology Services | 06/08/2007 |
| 0800 368 5 | Colt Technology Services | 06/08/2007 |
| 0800 368 6 | Colt Technology Services | 10/01/2008 |
| 0800 368 7 | Colt Technology Services | 10/01/2008 |
| 0800 368 8 | Colt Technology Services | 10/01/2008 |
| 0800 368 9 | Colt Technology Services | 10/01/2008 |
| 0800 369 8 | Affiniti Integrated Solutions Limited | 21/02/2006 |
| 0800 369 9 | London Central Communications Ltd | 11/12/2006 |
| 0800 376 | Verizon UK Limited | 24/07/1995 |
| 0800 377 7 | TalkTalk Communications Limited | 29/06/2006 |
| 0800 380 0 | TalkTalk Communications Limited | 20/02/2006 |
| 0800 381 1 | Commi Holdings Limited | 16/11/2016 |
| 0800 385 0 | Transaction Network Services (UK) Limited | 17/06/2020 |
| 0800 385 1 | Transaction Network Services (UK) Limited | 17/06/2020 |
| 0800 385 2 | Virgin Media Limited | 08/04/2016 |
| 0800 385 3 | Transaction Network Services (UK) Limited | 17/06/2020 |
| 0800 385 4 | Transaction Network Services (UK) Limited | 17/06/2020 |
| 0800 385 5 | Transaction Network Services (UK) Limited | 17/06/2020 |
| 0800 385 6 | Transaction Network Services (UK) Limited | 17/06/2020 |
| 0800 385 7 | Transaction Network Services (UK) Limited | 17/06/2020 |
| 0800 385 8 | Virgin Media Limited | 07/02/2020 |
| 0800 385 9 | Transaction Network Services (UK) Limited | 17/06/2020 |
| 0800 389 | BT | 17/04/1998 |
| 0800 392 3 | The Excell Group Limited | 26/09/2006 |
| 0800 395 1 | Alphatalk Limited | 30/01/2014 |
| 0800 404 5 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 404 6 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 404 7 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 404 8 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 404 9 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 408 0 | Virgin Media Limited | 08/04/2016 |
| 0800 408 1 | Virgin Media Limited | 08/04/2016 |
| 0800 408 2 | Virgin Media Limited | 08/04/2016 |
| 0800 408 3 | Virgin Media Limited | 08/04/2016 |
| 0800 408 4 | Virgin Media Limited | 08/04/2016 |
| 0800 408 5 | Virgin Media Limited | 08/04/2016 |
| 0800 408 6 | Virgin Media Limited | 08/04/2016 |
| 0800 408 7 | Virgin Media Limited | 08/04/2016 |
| 0800 408 8 | Virgin Media Limited | 08/04/2016 |
| 0800 408 9 | Virgin Media Limited | 08/04/2016 |
| 0800 409 6 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 410 1 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 410 2 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 411 5 | Chess Limited | 10/04/2018 |
| 0800 411 8 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 412 5 | Nextec UK Limited | 26/11/2013 |
| 0800 414 8 | BT | 06/04/2006 |
| 0800 422 0 | Affiniti Integrated Solutions Limited | 30/04/2003 |
| 0800 432 0 | BT | 03/11/2004 |
| 0800 432 2 | Assume Nothing Limited | 07/11/2007 |
| 0800 433 2 | Telecoms World PLC | 01/05/2008 |
| 0800 433 4 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 433 7 | Inet Telecoms Ltd (Voipfone) | 12/05/2016 |
| 0800 434 6 | BT | 03/11/2004 |
| 0800 437 0 | Buzz Networks Limited | 27/07/2000 |
| 0800 440 2 | Call Stream Limited | 21/12/2005 |
| 0800 441 4 | FUSION TELECOM LTD | 14/05/2020 |
| 0800 445 1 | Technology Distribution Limited | 02/11/2009 |
| 0800 448 0 | Affiniti Integrated Solutions Limited | 01/08/2018 |
| 0800 448 8 | TTNC Limited | 02/10/2013 |
| 0800 456 1 | BT | 15/06/2005 |
| 0800 456 5 | BT | 06/04/2006 |
| 0800 458 | TalkTalk Communications Limited | 09/10/2003 |
| 0800 459 9 | I-NET COMMUNICATIONS GROUP PLC | 28/10/2016 |
| 0800 464 0 | Invosys Limited | 24/08/2015 |
| 0800 464 3 | BT | 29/03/2006 |
| 0800 464 7 | Inet Telecoms Ltd (Voipfone) | 18/07/2018 |
| 0800 466 1 | TalkTalk Communications Limited | 02/02/2007 |
| 0800 468 1 | TTNC Limited | 02/10/2013 |
| 0800 470 0 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 470 1 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 470 2 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 470 3 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 470 4 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 470 8 | BT | 31/07/2013 |
| 0800 471 | Vodafone Ltd (C&W) | 06/05/2014 |
| 0800 472 5 | Telecom2 Limited | 29/07/2009 |
| 0800 473 0 | Telecom2 Limited | 29/07/2009 |
| 0800 474 8 | Premier Voicemail Ltd | 15/11/2012 |
| 0800 475 5 | Telecom2 Limited | 20/10/2015 |
| 0800 476 2 | ATH LTD | 09/03/2017 |
| 0800 479 | Virgin Media Limited | 04/11/1997 |
| 0800 484 0 | Gamma Telecom Holdings Ltd | 25/03/2014 |
| 0800 488 0 | IM Software Ltd | 28/05/2009 |
| 0800 494 0 | Virtual Talk Ltd | 23/04/2014 |
| 0800 496 | Lumen Technologies UK Limited | 16/10/1995 |
| 0800 497 0 | Virgin Media Limited | 01/03/2016 |
| 0800 500 3 | BT | 06/04/2006 |
| 0800 505 3 | Vodafone Ltd (Thus) | 15/02/2012 |
| 0800 505 4 | GTT-EMEA LTD | 14/10/2021 |
| 0800 508 8 | I-NET COMMUNICATIONS GROUP PLC | 12/02/2008 |
| 0800 510 5 | Solutios Limited | 15/09/2008 |
| 0800 511 8 | TTNC Limited | 02/10/2013 |
| 0800 519 | Virgin Media Limited | 04/11/1997 |
| 0800 520 0 | Magrathea Telecommunications Limited | 26/01/2007 |
| 0800 520 2 | Numbergroup Utilities Ltd | 29/10/2012 |
| 0800 524 4 | Magrathea Telecommunications Limited | 27/03/2008 |
| 0800 524 7 | 24 SEVEN CLOUD COMMUNICATIONS LTD | 07/10/2019 |
| 0800 528 | Lumen Technologies UK Limited | 07/12/1995 |
| 0800 529 8 | Virgin Media Limited | 08/04/2016 |
| 0800 530 0 | Barritel Limited | 09/05/2005 |
| 0800 531 6 | Affiniti Integrated Solutions Limited | 29/09/2000 |
| 0800 533 5 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 534 5 | Barritel Limited | 09/05/2005 |
| 0800 535 3 | Premier Voicemail Ltd | 12/08/2005 |
| 0800 538 5 | Colt Technology Services | 08/05/2015 |
| 0800 540 4 | Affiniti Integrated Solutions Limited | 24/09/2013 |
| 0800 542 | TalkTalk Communications Limited | 20/07/2006 |
| 0800 545 3 | BT | 06/04/2006 |
| 0800 546 0 | Lumen Technologies UK Limited | 03/08/2006 |
| 0800 550 1 | Call Stream Limited | 17/02/2011 |
| 0800 550 7 | Internet of Things Limited | 14/07/2021 |
| 0800 550 9 | Internet of Things Limited | 14/07/2021 |
| 0800 553 5 | Minotaur Telecom Limited | 31/01/2013 |
| 0800 554 0 | BT | 30/04/2014 |
| 0800 554 1 | BT | 30/04/2014 |
| 0800 554 2 | BT | 30/04/2014 |
| 0800 559 3 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 561 | Virgin Media Limited | 10/09/1997 |
| 0800 564 2 | Vodafone Ltd (Thus) | 15/02/2012 |
| 0800 566 0 | Sark Telecom B.V. | 10/11/2009 |
| 0800 566 8 | 08Direct Limited | 05/05/2010 |
| 0800 567 0 | Commi Holdings Limited | 16/11/2016 |
| 0800 567 4 | BT | 06/04/2006 |
| 0800 567 7 | Telecoms World PLC | 06/02/2007 |
| 0800 570 9 | OVH Limited | 26/07/2010 |
| 0800 575 1 | Supported Business Limited | 21/06/2016 |
| 0800 578 8 | Tango Networks UK Ltd | 04/06/2020 |
| 0800 583 | TalkTalk Communications Limited | 14/10/2013 |
| 0800 587 | BT | 23/10/2000 |
| 0800 588 4 | TalkTalk Communications Limited | 02/02/2007 |
| 0800 593 0 | Cloud Telecom Ltd | 30/01/2012 |
| 0800 593 1 | Cloud Telecom Ltd | 30/01/2012 |
| 0800 593 2 | Cloud Telecom Ltd | 30/01/2012 |
| 0800 593 3 | Cloud Telecom Ltd | 30/01/2012 |
| 0800 593 4 | Cloud Telecom Ltd | 30/01/2012 |
| 0800 594 | TalkTalk Communications Limited | 14/10/2013 |
| 0800 596 | New Call Telecom Ltd | 08/05/2015 |
| 0800 597 | Virgin Media Limited | 23/05/2002 |
| 0800 599 1 | AQL Wholesale Ltd | 04/08/2015 |
| 0800 599 9 | Telecoms World PLC | 06/02/2007 |
| 0800 601 1 | Zestel Limited | 19/02/2013 |
| 0800 603 5 | Wizaner Limited | 31/12/2001 |
| 0800 610 1 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 610 2 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 611 8 | TTNC Limited | 02/10/2013 |
| 0800 612 | Nexus Telecommunications Limited | 13/12/2000 |
| 0800 613 3 | Zsquare Global Solutions Ltd | 10/01/2012 |
| 0800 619 | Swiftnet Ltd | 09/06/1999 |
| 0800 620 0 | I-NET COMMUNICATIONS GROUP PLC | 29/08/2012 |
| 0800 622 6 | Telecoms World PLC | 07/12/2007 |
| 0800 625 0 | Barritel Limited | 09/05/2005 |
| 0800 628 9 | 2-Sell-It Ltd | 12/04/2006 |
| 0800 630 0 | TalkTalk Communications Limited | 06/04/2005 |
| 0800 631 | KDDI Europe Ltd | 17/07/1997 |
| 0800 633 5 | BT | 28/06/2005 |
| 0800 633 8 | Lumen Technologies UK Limited | 21/02/2005 |
| 0800 634 | Vodafone Ltd (Thus) | 15/02/2012 |
| 0800 635 | Alphatalk Limited | 30/01/2014 |
| 0800 640 0 | Colt Technology Services | 16/12/2008 |
| 0800 640 1 | Colt Technology Services | 16/12/2008 |
| 0800 640 2 | Colt Technology Services | 16/12/2008 |
| 0800 640 3 | Colt Technology Services | 16/12/2008 |
| 0800 640 4 | Colt Technology Services | 16/12/2008 |
| 0800 640 5 | Colt Technology Services | 16/12/2008 |
| 0800 640 6 | Colt Technology Services | 16/12/2008 |
| 0800 640 7 | Colt Technology Services | 16/12/2008 |
| 0800 640 8 | Colt Technology Services | 16/12/2008 |
| 0800 640 9 | Colt Technology Services | 16/12/2008 |
| 0800 644 0 | Telecoms World PLC | 02/12/2008 |
| 0800 644 1 | Telecoms World PLC | 02/12/2008 |
| 0800 644 2 | Telecoms World PLC | 02/12/2008 |
| 0800 644 3 | Telecoms World PLC | 02/12/2008 |
| 0800 644 4 | Number Solutions Ltd | 08/03/2007 |
| 0800 644 5 | Telecoms World PLC | 02/12/2008 |
| 0800 644 6 | Telecoms World PLC | 07/12/2007 |
| 0800 644 7 | Telecoms World PLC | 02/12/2008 |
| 0800 644 8 | Telecoms World PLC | 02/12/2008 |
| 0800 651 | Swiftnet Ltd | 09/06/1999 |
| 0800 652 | Gamma Telecom Holdings Ltd | 04/12/2002 |
| 0800 653 | Singtel Europe Ltd | 18/09/1998 |
| 0800 654 1 | Resilient PLC | 07/02/2012 |
| 0800 655 6 | Elitetele.com plc | 04/10/2002 |
| 0800 656 9 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 668 1 | Call Stream Limited | 20/02/2007 |
| 0800 668 9 | Promotions4All Ltd | 23/12/2009 |
| 0800 669 6 | Telecoms World PLC | 07/12/2007 |
| 0800 670 3 | Networks Direct plc | 01/07/2002 |
| 0800 677 0 | Numbers Telecom Limited | 01/02/2016 |
| 0800 677 1 | Telecoms World PLC | 01/05/2008 |
| 0800 678 1 | BT | 03/11/2004 |
| 0800 678 3 | BT | 29/03/2006 |
| 0800 678 5 | Vodafone Ltd (C&W) | 18/06/2013 |
| 0800 680 0 | Magrathea Telecommunications Limited | 26/01/2007 |
| 0800 680 9 | Nodemax Limited | 20/05/2008 |
| 0800 681 6 | BT | 29/03/2006 |
| 0800 685 0 | Call Stream Limited | 17/02/2011 |
| 0800 686 6 | UK BROADBAND LIMITED | 05/12/2013 |
| 0800 688 8 | TalkTalk Communications Limited | 29/06/2006 |
| 0800 688 9 | Telecoms World PLC | 01/05/2008 |
| 0800 689 | Vodafone Ltd (C&W) | 06/05/2014 |
| 0800 690 6 | Core Telecom Limited | 09/03/2016 |
| 0800 691 1 | Core Telecom Limited | 27/07/2011 |
| 0800 692 | Lumen Technologies UK Limited | 07/12/1995 |
| 0800 694 | Virgin Media Limited | 08/04/2016 |
| 0800 695 | Visionate Ltd | 14/10/1999 |
| 0800 696 5 | Premier Voicemail Ltd | 28/11/2013 |
| 0800 698 | Inclarity Communications Limited | 23/01/2014 |
| 0800 699 0 | Telecoms World PLC | 07/12/2007 |
| 0800 702 2 | Affiniti Integrated Solutions Limited | 01/08/2018 |
| 0800 705 0 | Bellingham Telecommunications Ltd | 07/06/2011 |
| 0800 707 2 | InTouch Communication Services Limited | 27/02/2006 |
| 0800 707 4 | SMARTVOICE LTD | 02/09/2020 |
| 0800 707 6 | BT | 03/11/2004 |
| 0800 707 9 | Internet of Things Limited | 14/07/2021 |
| 0800 710 1 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 711 7 | Nationwide Telephone Assistance Ltd | 02/09/2005 |
| 0800 714 4 | I-NET COMMUNICATIONS GROUP PLC | 04/10/2016 |
| 0800 731 | BT | 07/05/1997 |
| 0800 734 | Instafone Plc | 09/09/1998 |
| 0800 735 | JT (Jersey) Limited | 13/03/1996 |
| 0800 740 8 | Buzz Networks Limited | 26/03/2002 |
| 0800 747 1 | Premier Voicemail Ltd | 03/07/2007 |
| 0800 747 6 | Callmonitor Limited | 27/09/2004 |
| 0800 748 3 | ATH LTD | 09/03/2017 |
| 0800 755 5 | Nationwide Telephone Assistance Ltd | 02/09/2005 |
| 0800 756 | BT | 07/02/2005 |
| 0800 757 3 | LinkUP Mitaka Ltd - T/A The Big Word | 07/10/2010 |
| 0800 759 0 | Sky UK Limited | 16/11/2016 |
| 0800 759 1 | Sky UK Limited | 16/11/2016 |
| 0800 759 2 | Sky UK Limited | 16/11/2016 |
| 0800 759 4 | Sky UK Limited | 16/11/2016 |
| 0800 759 9 | Sky UK Limited | 16/11/2016 |
| 0800 761 3 | Sky UK Limited | 11/12/2013 |
| 0800 763 1 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 765 0 | Commi Holdings Limited | 16/11/2016 |
| 0800 768 0 | KDDI Europe Ltd | 28/08/2009 |
| 0800 769 | KDDI Europe Ltd | 16/04/2010 |
| 0800 770 1 | Digitech Solutions Global Limited | 08/05/2008 |
| 0800 771 0 | Barritel Limited | 09/05/2005 |
| 0800 772 0 | Kalnet4U Ltd | 25/11/2011 |
| 0800 772 3 | Kalnet4U Ltd | 12/12/2013 |
| 0800 773 4 | Core Telecom Limited | 07/02/2013 |
| 0800 774 0 | Core Telecom Limited | 07/02/2013 |
| 0800 774 7 | Telecoms World PLC | 01/05/2008 |
| 0800 775 0 | TeleSurf Limited | 18/11/2009 |
| 0800 776 5 | FleXtel Limited | 17/11/2011 |
| 0800 778 0 | Swiftel Limited | 31/10/2012 |
| 0800 778 9 | Microtalk Europe Limited | 10/03/2016 |
| 0800 779 7 | Telecoms World PLC | 01/05/2008 |
| 0800 781 | TalkTalk Communications Limited | 09/10/2003 |
| 0800 783 | BT | 30/07/1997 |
| 0800 785 1 | WIGHTFIBRE LIMITED | 01/03/2006 |
| 0800 786 0 | Nowtel Wholesale Limited | 26/01/2016 |
| 0800 786 1 | Nowtel Wholesale Limited | 18/02/2011 |
| 0800 787 0 | 08Direct Limited | 02/08/2011 |
| 0800 787 9 | Barritel Limited | 09/05/2005 |
| 0800 788 0 | 08Direct Limited | 19/02/2013 |
| 0800 799 9 | Telecoms World PLC | 01/05/2008 |
| 0800 802 1 | AQL Wholesale Ltd | 17/08/2012 |
| 0800 802 9 | TGL Services (UK) Ltd | 09/01/2018 |
| 0800 803 0 | TalkTalk Communications Limited | 06/04/2005 |
| 0800 804 4 | Affiniti Integrated Solutions Limited | 24/09/2013 |
| 0800 804 6 | TalkTalk Communications Limited | 20/07/2006 |
| 0800 804 7 | TalkTalk Communications Limited | 20/07/2006 |
| 0800 804 8 | Gamma Telecom Holdings Ltd | 13/02/2002 |
| 0800 808 2 | Gold Telecom Limited | 04/05/2004 |
| 0800 808 3 | TalkTalk Communications Limited | 01/05/2014 |
| 0800 808 4 | One Network Limited | 12/04/2011 |
| 0800 808 5 | (AQ) LIMITED | 28/09/2012 |
| 0800 808 6 | Mi Telecom Limited | 15/04/2014 |
| 0800 808 7 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 808 9 | Invosys Limited | 28/06/2012 |
| 0800 810 0 | I-NET COMMUNICATIONS GROUP PLC | 26/10/2007 |
| 0800 810 1 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 810 8 | Mi Telecom Limited | 29/01/2014 |
| 0800 811 9 | Syntec Limited | 12/08/2003 |
| 0800 812 1 | Microtalk Europe Limited | 10/03/2016 |
| 0800 812 2 | I-NET COMMUNICATIONS GROUP PLC | 19/10/2017 |
| 0800 814 | Swiftnet Ltd | 09/06/1999 |
| 0800 817 4 | Tipicall Limited | 12/12/2013 |
| 0800 818 6 | BT | 06/04/2006 |
| 0800 819 9 | TalkTalk Communications Limited | 18/12/2007 |
| 0800 820 2 | Numbergroup Utilities Ltd | 11/07/2011 |
| 0800 820 3 | Tipicall Limited | 12/12/2013 |
| 0800 822 3 | Real Time Telecoms Ltd | 21/08/2014 |
| 0800 824 7 | TTNC Limited | 02/10/2013 |
| 0800 825 0 | Barritel Limited | 09/05/2005 |
| 0800 830 3 | Numbergroup Utilities Ltd | 29/10/2012 |
| 0800 832 1 | FleXtel Limited | 17/11/2011 |
| 0800 836 | New Call Telecom Ltd | 12/12/2012 |
| 0800 837 0 | United Connect Limited | 22/03/2000 |
| 0800 837 1 | United Connect Limited | 22/03/2000 |
| 0800 840 | TalkTalk Communications Limited | 21/02/2008 |
| 0800 841 1 | Telecoms World Direct Ltd | 12/06/2014 |
| 0800 844 5 | Reality Network Services Limited | 03/06/2011 |
| 0800 845 6 | TGL Services (UK) Ltd | 02/02/2015 |
| 0800 845 7 | TGL Services (UK) Ltd | 02/02/2015 |
| 0800 847 7 | Relax Telecom Limited | 15/08/2014 |
| 0800 848 8 | 08 Numbers Ltd | 06/07/2005 |
| 0800 849 | Digital Space Group Limited | 24/12/2015 |
| 0800 852 1 | Digital Space Group Limited | 24/12/2015 |
| 0800 852 7 | Invoco Ltd | 30/07/2010 |
| 0800 856 | Six Degrees Technology Group Limited | 16/09/2020 |
| 0800 858 9 | Premier Voicemail Ltd | 10/08/2010 |
| 0800 859 5 | Content Guru Limited | 02/11/2007 |
| 0800 859 6 | Content Guru Limited | 09/11/2009 |
| 0800 860 0 | Barritel Limited | 09/05/2005 |
| 0800 860 3 | Syntec Limited | 18/09/2006 |
| 0800 860 4 | Syntec Limited | 18/09/2006 |
| 0800 860 6 | Affiniti Integrated Solutions Limited | 06/08/2015 |
| 0800 861 1 | IP Voice Networks Ltd | 11/07/2017 |
| 0800 862 0 | AQL Wholesale Ltd | 20/10/2004 |
| 0800 865 4 | Telecoms World PLC | 07/12/2007 |
| 0800 870 8 | Tipicall Limited | 12/12/2013 |
| 0800 872 3 | ATH LTD | 09/03/2017 |
| 0800 874 4 | Citrus Telecommunications Ltd | 21/04/2016 |
| 0800 875 8 | Vibe Communications UK Ltd | 31/03/2008 |
| 0800 876 0 | Commi Holdings Limited | 16/11/2016 |
| 0800 876 6 | BT | 03/11/2004 |
| 0800 876 9 | TelecomIQ Limited | 13/05/2020 |
| 0800 877 0 | Adepteo Limited | 27/02/2015 |
| 0800 877 2 | Real Time Telecoms Ltd | 08/10/2015 |
| 0800 877 8 | TalkTalk Communications Limited | 06/04/2005 |
| 0800 878 0 | IV Response Limited | 16/09/2005 |
| 0800 878 6 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 878 9 | Telecoms World Direct Ltd | 22/11/2006 |
| 0800 879 9 | Invade International Ltd | 13/01/2016 |
| 0800 880 3 | Nodemax Limited | 28/10/2008 |
| 0800 880 6 | Nodemax Limited | 28/10/2008 |
| 0800 880 7 | Invosys Limited | 16/04/2014 |
| 0800 880 9 | Timico Partner Services Limited | 02/04/2003 |
| 0800 881 3 | Nodemax Limited | 28/10/2008 |
| 0800 881 5 | TalkTalk Communications Limited | 18/12/2007 |
| 0800 881 6 | Atlantic Communications Corp Ltd | 18/11/2013 |
| 0800 881 8 | Gamma Telecom Holdings Ltd | 26/10/2012 |
| 0800 882 1 | I-NET COMMUNICATIONS GROUP PLC | 18/02/2015 |
| 0800 882 4 | Barritel Limited | 09/05/2005 |
| 0800 883 0 | IV Response Limited | 09/03/2002 |
| 0800 883 2 | IV Response Limited | 28/08/2007 |
| 0800 883 8 | IV Response Limited | 16/09/2005 |
| 0800 884 0 | Gamma Telecom Holdings Ltd | 20/11/2017 |
| 0800 884 1 | Tabsoft Limited | 28/10/2008 |
| 0800 884 5 | ATH LTD | 09/03/2017 |
| 0800 887 0 | FleXtel Limited | 19/10/2018 |
| 0800 888 6 | Telecoms World PLC | 01/05/2008 |
| 0800 901 2 | Verizon UK Limited | 05/10/2001 |
| 0800 902 0 | TalkTalk Communications Limited | 27/10/2004 |
| 0800 904 7 | Vodafone Ltd (C&W) | 13/09/2013 |
| 0800 905 5 | Number Services Ltd. | 22/11/2018 |
| 0800 907 | GCI Network Solutions Ltd | 19/04/2017 |
| 0800 909 8 | City Numbers Ltd | 03/05/2011 |
| 0800 909 9 | InTouch Communication Services Limited | 13/05/2003 |
| 0800 910 0 | I-NET COMMUNICATIONS GROUP PLC | 03/11/2010 |
| 0800 910 1 | Numbergroup Utilities Ltd | 19/10/2010 |
| 0800 910 3 | Digitech Solutions Global Limited | 28/06/2012 |
| 0800 911 5 | Marathon Telecom Limited | 29/06/2011 |
| 0800 912 | Vodafone Ltd (Energis) | 30/05/2006 |
| 0800 913 | Voicetec Systems Ltd | 27/01/2003 |
| 0800 914 | Tata Communications (UK) Ltd | 22/01/2010 |
| 0800 915 | Affiniti Integrated Solutions Limited | 28/10/1997 |
| 0800 916 | BT | 10/02/1998 |
| 0800 917 | BT | 10/02/1998 |
| 0800 920 2 | Numbergroup Utilities Ltd | 11/07/2011 |
| 0800 921 2 | M247 Ltd | 08/05/2015 |
| 0800 923 | Virgin Media Limited | 08/04/2016 |
| 0800 924 7 | TTNC Limited | 02/10/2013 |
| 0800 927 3 | ATH LTD | 09/03/2017 |
| 0800 928 3 | ATH LTD | 09/03/2017 |
| 0800 930 0 | Mars Communications Limited | 07/03/2008 |
| 0800 931 | Atlas Interactive Group Limited | 02/11/1999 |
| 0800 933 0 | Lanonyx Telecom Limited | 22/08/2011 |
| 0800 933 6 | Dantec Enterprises Ltd | 11/08/2005 |
| 0800 933 7 | Telesoft Technologies Limited | 10/05/2005 |
| 0800 934 7 | Gamma Telecom Holdings Ltd | 23/03/2021 |
| 0800 937 0 | Global Electroteks Ltd | 16/02/2001 |
| 0800 949 4 | Telecoms World PLC | 07/12/2007 |
| 0800 949 6 | Citrus Telecommunications Ltd | 28/08/2002 |
| 0800 949 9 | Telecoms World PLC | 02/12/2008 |
| 0800 950 0 | Relax Telecom Limited | 18/11/2014 |
| 0800 950 6 | Aloha Telecommunications Ltd | 18/08/2011 |
| 0800 952 | Virgin Media Limited | 19/02/1997 |
| 0800 953 | Virgin Media Limited | 08/04/2016 |
| 0800 954 | TalkTalk Communications Limited | 20/07/2006 |
| 0800 955 0 | TTNC Limited | 02/10/2013 |
| 0800 955 1 | TTNC Limited | 02/10/2013 |
| 0800 955 2 | TTNC Limited | 01/10/2013 |
| 0800 955 3 | TTNC Limited | 01/10/2013 |
| 0800 955 4 | TTNC Limited | 01/10/2013 |
| 0800 955 5 | TalkTalk Communications Limited | 13/08/2004 |
| 0800 955 6 | TTNC Limited | 01/10/2013 |
| 0800 955 7 | TTNC Limited | 01/10/2013 |
| 0800 955 8 | TTNC Limited | 01/10/2013 |
| 0800 956 | EE Limited ( TM) | 21/02/2000 |
| 0800 957 | TalkTalk Communications Limited | 07/11/2013 |
| 0800 958 9 | Telecoms World PLC | 02/12/2008 |
| 0800 959 3 | Hospedia Limited | 05/04/2000 |
| 0800 959 6 | Premier Voicemail Ltd | 11/09/2006 |
| 0800 970 | Vodafone Ltd (Thus) | 15/02/2012 |
| 0800 971 7 | TelecomIQ Limited | 22/07/2013 |
| 0800 972 3 | Microtalk Europe Limited | 10/03/2016 |
| 0800 974 | Virgin Media Limited | 21/08/2002 |
| 0800 975 | Vodafone Ltd (Energis) | 30/05/2006 |
| 0800 976 | Sure (Guernsey) Limited | 07/05/1997 |
| 0800 977 4 | TalkTalk Communications Limited | 08/03/2004 |
| 0800 977 5 | TalkTalk Communications Limited | 08/03/2004 |
| 0800 977 6 | TalkTalk Communications Limited | 08/03/2004 |
| 0800 977 7 | TalkTalk Communications Limited | 08/03/2004 |
| 0800 977 8 | TalkTalk Communications Limited | 08/03/2004 |
| 0800 978 7 | In2com Ltd | 20/12/2011 |
| 0800 978 8 | Nexus Telecommunications Limited | 16/06/2009 |
| 0800 978 9 | Business Broadcast Communications Limited | 19/10/2009 |
| 0800 979 0 | Served Up Limited | 03/06/2008 |
| 0800 979 1 | 24 SEVEN CLOUD COMMUNICATIONS LTD | 07/10/2019 |
| 0800 980 | Vodafone Ltd (Energis) | 30/05/2006 |
| 0800 982 3 | iHub 2 Limited | 17/06/2016 |
| 0800 983 | Redcentric Solutions Limited | 25/05/2016 |
| 0800 986 | ESAT Telecommunications (UK) Ltd | 02/09/1999 |
| 0800 987 0 | Calltracks Limited | 29/07/2013 |
| 0800 987 1 | Andrews & Arnold Ltd | 13/10/2006 |
| 0800 987 2 | IM Software Ltd | 20/03/2012 |
| 0800 987 4 | 8x8 UK Limited | 11/12/2009 |
| 0800 987 5 | Telecoms World PLC | 07/12/2007 |
| 0800 987 7 | Telecoms World PLC | 13/04/2007 |
| 0800 987 8 | Inclarity Communications Limited | 23/01/2014 |
| 0800 987 9 | Sound Advertising Ltd | 30/10/2007 |
| 0800 988 | TalkTalk Communications Limited | 20/07/2006 |
| 0800 989 0 | Inclarity Communications Limited | 23/01/2014 |
| 0800 990 3 | TalkTalk Communications Limited | 25/01/2008 |
| 0800 990 6 | ETC Telecom Limited | 31/08/2007 |
| 0800 990 7 | Chess Limited | 10/04/2018 |
| 0800 993 0 | Relax Telecom Limited | 09/02/2009 |
| 0800 994 0 | Direct2Internet Ltd | 24/10/2002 |
| 0800 994 9 | Telecoms World PLC | 01/05/2008 |
| 0800 995 1 | TalkTalk Communications Limited | 20/07/2006 |
| 0800 995 6 | NFON UK Ltd | 18/07/2018 |
| 0800 996 0 | Inclarity Communications Limited | 23/01/2014 |
| 0800 996 1 | TalkTalk Communications Limited | 20/07/2006 |
| 0800 997 8 | Call Stream Limited | 20/02/2007 |
| 0800 998 1 | Content Guru Limited | 02/11/2007 |
| 0800 998 6 | Abel & Co (Scotland) Ltd | 11/06/2002 |
| 0800 998 7 | Telecoms World PLC | 02/12/2008 |
| 0800 998 9 | Net-Work Internet Ltd | 24/09/2007 |
| 0800 999 0 | Alphatalk Limited | 11/09/2007 |
| 0800 999 1 | Kalnet4U Ltd | 10/08/2015 |
| 0800 999 2 | Windsor Telecom Ltd | 18/10/2007 |
| 0800 999 3 | Windsor Telecom Ltd | 18/10/2007 |
| 0800 999 4 | Windsor Telecom Ltd | 18/10/2007 |
| 0800 999 5 | Windsor Telecom Ltd | 18/10/2007 |
| 0800 999 6 | Windsor Telecom Ltd | 18/10/2007 |
| 0800 999 7 | Windsor Telecom Ltd | 18/10/2007 |
| 0800 999 8 | Windsor Telecom Ltd | 18/10/2007 |
| 0800 999 9 | Vodafone Ltd (C&W) | 13/09/2013 |