UK area code
01666 area code — Malmesbury
01666 is Ofcom’s Malmesbury numbering area, in Wiltshire, South West England. 88 phone companies hold its 110 allocated number blocks. Its numbers are written like 01666 234 567. The nearest other codes are 01249 Chippenham (14 km) and 01285 Cirencester (17 km).
01666 at a glance
- Ofcom area name
- Malmesbury
- County
- Wiltshire
- Council area
- Wiltshire
- Region
- South West England
- Number format
- 01666 234 567 (4+6)
- Local calls
- Full number recommended
- Current code since
- 1995 (previously 0666)
- Allocated blocks
- 110 of 370 (30%) across 88 providers
- Newest block
- 26 January 2026 (1 in the last 12 months)
Sources: Ofcom numbering data (weekly) and area-code list, Ofcom Numbering Plan, ONS geography.
If a 01666 number called you
No clear pattern in reports for these numbers yet. If a call worried you:
- 1
Call back on a number you trust
If a caller says they're your bank, HMRC, a courier or a council, hang up and ring the organisation on the number from its website or your statement, never the number that called you. Caller ID can be faked.
- 2
Forward it to 7726
On a mobile, copy the caller's number from your recent calls and text it to 7726 (it spells SPAM). Scam texts can be forwarded to 7726 as they are. It's free, and your network uses the reports to investigate and block numbers.
- 3
Stop sales calls
Register your landline and mobile free with the Telephone Preference Service (0345 070 0707). Legitimate UK marketers must check it; calls should drop within 28 days. It won't stop scammers.
- 4
If you lost money or shared details
Call your bank on the number on your card (or 159 to reach most UK banks safely), then report it to Report Fraud online or on 0300 123 2040. Report Fraud replaced Action Fraud on 4 December 2025 for England, Wales and Northern Ireland; in Scotland call Police Scotland on 101.
01666 history and number format
Number format: Numbers on 01666 use Ofcom's 4+6 format: the 5-digit code (including the leading 0) followed by a 6-digit local number — written like 01666 234 567.
Before 1995: 01666 took its current form at PhONEday on 16 April 1995, when a "1" was inserted into every UK geographic code — before that the area dialled 0666.
Local dialling: Traditionally not from another 01666 landline, but it now depends on your provider: Ofcom stopped requiring providers to offer local (code-free) dialling on 11 March 2022. Dialling 01666 first always works, and mobiles always need it.
Allocation record: the oldest number block still visible on 01666 was allocated on 15 July 1994, and the most recent on 26 January 2026. 1 block was allocated in the last 12 months — newly-activated ranges with no call history, which is worth knowing when an unfamiliar 01666 number rings (see the weekly numbering changelog for every new allocation.)
Phone companies holding 01666 numbers
Every Ofcom range holder with blocks on 01666, by allocated blocks. The holder is the company Ofcom allocated the block to; a number can since have been ported to another provider (see range holder vs current provider).
| Range holder | Allocated | All blocks | First block | Latest block |
|---|---|---|---|---|
| BT | 10 | 10 | 15 July 1994 | 14 November 1994 |
| Vodafone Ltd (C&W) | 8 | 8 | 9 September 2013 | 10 November 2021 |
| GCI Network Solutions Limited | 3 | 3 | 26 April 2017 | 22 December 2023 |
| Colt Technology Services | 2 | 2 | 20 June 2016 | 8 March 2022 |
| Digital Space Group Limited | 2 | 2 | 16 May 2008 | 15 March 2016 |
| Sky UK Limited | 2 | 2 | 1 July 2013 | 8 September 2020 |
| TalkTalk Communications Limited | 2 | 2 | 20 January 2012 | 20 January 2012 |
| (AQ) LIMITED | 1 | 1 | 12 September 2012 | 12 September 2012 |
| 24 Seven Cloud Communications Ltd | 1 | 1 | 17 January 2020 | 17 January 2020 |
| 8x8 Communications UK Limited | 1 | 1 | 5 April 2012 | 5 April 2012 |
| AQL Wholesale Ltd | 1 | 1 | 1 November 2004 | 1 November 2004 |
| Adepteo Limited | 1 | 1 | 17 January 2017 | 17 January 2017 |
| Andrews & Arnold (Numbers) Ltd | 1 | 1 | 27 March 2009 | 27 March 2009 |
| Atomstream Limited | 1 | 1 | 14 May 2010 | 14 May 2010 |
| Barritel Limited | 1 | 1 | 26 June 2007 | 26 June 2007 |
| Belgacom International Carrier Services SA | 1 | 1 | 9 April 2020 | 9 April 2020 |
| Bicom Systems EURL | 1 | 1 | 1 March 2012 | 1 March 2012 |
| Bink Networks Ltd | 1 | 1 | 11 April 2023 | 11 April 2023 |
| CFL Communications Ltd | 1 | 1 | 14 July 2009 | 14 July 2009 |
| Calltracks Limited | 1 | 1 | 31 January 2014 | 31 January 2014 |
| Content Guru Limited | 1 | 1 | 12 October 2012 | 12 October 2012 |
| Convergence Group (wireless) Networks Limited | 1 | 1 | 21 May 2019 | 21 May 2019 |
| DIDWW Ireland Limited | 1 | 1 | 21 January 2019 | 21 January 2019 |
| Dial 9 Communications Limited | 1 | 1 | 10 December 2019 | 10 December 2019 |
| Digitech Solutions Global Limited | 1 | 1 | 27 April 2010 | 27 April 2010 |
| EVE CONNECT LTD | 1 | 1 | 15 June 2022 | 15 June 2022 |
| Flextel Limited | 1 | 1 | 23 November 2005 | 23 November 2005 |
| Fuse 2 Communications Ltd | 1 | 1 | 3 July 2017 | 3 July 2017 |
| Gamma Telecom Holdings Limited | 1 | 1 | 4 May 2005 | 4 May 2005 |
| Hello Telecom (UK) Limited | 1 | 1 | 17 November 2011 | 17 November 2011 |
Showing the 30 largest of 88 holders.
All number blocks on 01666first 200 of 370, by prefix
| Prefix | Status | Range holder |
|---|---|---|
| +44 166600 | Protected | — |
| +44 166601 | Protected | — |
| +44 166602 | Protected | — |
| +44 166603 | Protected | — |
| +44 166604 | Protected | — |
| +44 166605 | Protected | — |
| +44 166606 | Protected | — |
| +44 166607 | Protected | — |
| +44 166608 | Protected | — |
| +44 166609 | Protected | — |
| +44 166610 | Protected | — |
| +44 166611 | Protected | — |
| +44 166612 | Protected | — |
| +44 166613 | Protected | — |
| +44 166614 | Protected | — |
| +44 166615 | Protected | — |
| +44 166616 | Protected | — |
| +44 166617 | Protected | — |
| +44 166618 | Protected | — |
| +44 166619 | Protected | — |
| +44 166620 | Allocated | TelNG Limited |
| +44 166621 | Allocated | Voiceflex Limited |
| +44 166622 | Allocated | Barritel Limited |
| +44 1666230 | Protected | — |
| +44 1666231 | Protected | — |
| +44 1666232 | Protected | — |
| +44 1666233 | Protected | — |
| +44 1666234 | Protected | — |
| +44 1666235 | Protected | — |
| +44 1666236 | Protected | — |
| +44 1666237 | Protected | — |
| +44 1666238 | Allocated | TalkTalk Communications Limited |
| +44 1666239 | Allocated | TalkTalk Communications Limited |
| +44 166624 | Protected | — |
| +44 166625 | Allocated | (AQ) LIMITED |
| +44 166626 | Allocated | Localphone Limited |
| +44 166627 | Allocated | VoIP-Un Limited |
| +44 1666280 | Allocated | Fuse 2 Communications Ltd |
| +44 1666281 | Allocated | EVE CONNECT LTD |
| +44 1666282 | Allocated | Adepteo Limited |
| +44 1666283 | Allocated | Zapappi Ltd |
| +44 1666284 | Allocated | 24 Seven Cloud Communications Ltd |
| +44 1666285 | Allocated | Belgacom International Carrier Services SA |
| +44 1666286 | Allocated | DIDWW Ireland Limited |
| +44 1666287 | Allocated | ICUK Computing Services Limited |
| +44 1666288 | Allocated | Number Services Ltd. |
| +44 1666289 | Allocated | IP Voice Networks Ltd |
| +44 166629 | Allocated | Nationwide Telephone Assistance Ltd |
| +44 166630 | Protected | — |
| +44 1666310 | Allocated | Nexbridge Communications Limited |
| +44 1666311 | Allocated | Sky UK Limited |
| +44 1666312 | Protected | — |
| +44 1666313 | Allocated | Convergence Group (wireless) Networks Limited |
| +44 1666314 | Allocated | Internexus Networks Limited |
| +44 1666315 | Allocated | Minotaur Telecom Limited |
| +44 1666316 | Protected | — |
| +44 1666317 | Allocated | Inet Telecoms Ltd (Voipfone) |
| +44 1666318 | Allocated | Hello Telecom (UK) Limited |
| +44 1666319 | Allocated | Orbtalk Limited |
| +44 166632 | Protected | — |
| +44 166633 | Allocated | Gamma Telecom Holdings Limited |
| +44 1666340 | Protected | — |
| +44 1666341 | Protected | — |
| +44 1666342 | Protected | — |
| +44 1666343 | Protected | — |
| +44 1666344 | Allocated | Six Degrees Technology Group Limited |
| +44 1666345 | Protected | — |
| +44 1666346 | Protected | — |
| +44 1666347 | Protected | — |
| +44 1666348 | Protected | — |
| +44 1666349 | Protected | — |
| +44 1666350 | Protected | — |
| +44 1666351 | Protected | — |
| +44 1666352 | Protected | — |
| +44 1666353 | Protected | — |
| +44 1666354 | Protected | — |
| +44 1666355 | Protected | — |
| +44 1666356 | Protected | — |
| +44 1666357 | Protected | — |
| +44 1666358 | Protected | — |
| +44 1666359 | Protected | — |
| +44 166636 | Allocated | IV Response Limited |
| +44 1666370 | Protected | — |
| +44 1666371 | Protected | — |
| +44 1666372 | Protected | — |
| +44 1666373 | Protected | — |
| +44 1666374 | Protected | — |
| +44 1666375 | Protected | — |
| +44 1666376 | Protected | — |
| +44 1666377 | Allocated | Spitfire Network Services Limited |
| +44 1666378 | Protected | — |
| +44 1666379 | Protected | — |
| +44 166638 | Protected | — |
| +44 166639 | Allocated | TTNC Limited |
| +44 166640 | Allocated | Redcentric Solutions Limited |
| +44 1666410 | Protected | — |
| +44 1666411 | Protected | — |
| +44 1666412 | Protected | — |
| +44 1666413 | Protected | — |
| +44 1666414 | Protected | — |
| +44 1666415 | Protected | — |
| +44 1666416 | Protected | — |
| +44 1666417 | Allocated | Digital Space Group Limited |
| +44 1666418 | Protected | — |
| +44 1666419 | Protected | — |
| +44 166642 | Allocated | Telecom2 Limited |
| +44 166643 | Allocated | Digital Space Group Limited |
| +44 166644 | Allocated | Net-Work Internet Ltd |
| +44 1666450 | Allocated | Voxbone SA |
| +44 1666451 | Protected | — |
| +44 1666452 | Protected | — |
| +44 1666453 | Protected | — |
| +44 1666454 | Protected | — |
| +44 1666455 | Protected | — |
| +44 1666456 | Protected | — |
| +44 1666457 | Protected | — |
| +44 1666458 | Protected | — |
| +44 1666459 | Protected | — |
| +44 166646 | Allocated | Nodemax Limited |
| +44 166647 | Protected | — |
| +44 166648 | Protected | — |
| +44 166649 | Allocated | Served Up Limited |
| +44 166650 | Allocated | BT |
| +44 166651 | Allocated | BT |
| +44 1666520 | Protected | — |
| +44 1666521 | Protected | — |
| +44 1666522 | Protected | — |
| +44 1666523 | Protected | — |
| +44 1666524 | Protected | — |
| +44 1666525 | Protected | — |
| +44 1666526 | Protected | — |
| +44 1666527 | Protected | — |
| +44 1666528 | Protected | — |
| +44 1666529 | Protected | — |
| +44 166653 | Allocated | Vodafone Ltd (C&W) |
| +44 166654 | Allocated | GCI Network Solutions Limited |
| +44 166655 | Allocated | BT |
| +44 1666560 | Allocated | Vodafone Ltd (C&W) |
| +44 1666561 | Allocated | Vodafone Ltd (C&W) |
| +44 1666562 | Allocated | Vodafone Ltd (C&W) |
| +44 1666563 | Allocated | Vodafone Ltd (C&W) |
| +44 1666564 | Allocated | Vodafone Ltd (C&W) |
| +44 1666565 | Allocated | Vodafone Ltd (C&W) |
| +44 1666566 | Protected | — |
| +44 1666567 | Protected | — |
| +44 1666568 | Protected | — |
| +44 1666569 | Allocated | Vodafone Ltd (C&W) |
| +44 166657 | Allocated | BT |
| +44 166658 | Allocated | Verizon UK Limited |
| +44 1666590 | Protected | — |
| +44 1666591 | Protected | — |
| +44 1666592 | Protected | — |
| +44 1666593 | Protected | — |
| +44 1666594 | Protected | — |
| +44 1666595 | Protected | — |
| +44 1666596 | Protected | — |
| +44 1666597 | Protected | — |
| +44 1666598 | Protected | — |
| +44 1666599 | Protected | — |
| +44 166660 | Allocated | Solutios Limited |
| +44 166661 | Quarantined | — |
| +44 166662 | Allocated | Mars Communications Limited |
| +44 166663 | Allocated | Telecoms World Direct Limited |
| +44 166664 | Allocated | Andrews & Arnold (Numbers) Ltd |
| +44 166665 | Quarantined | — |
| +44 166666 | Allocated | Invade International Ltd |
| +44 166667 | Allocated | CFL Communications Ltd |
| +44 166668 | Allocated | Nexus Telecommunications Limited |
| +44 166669 | Allocated | Lumen Technologies UK Limited |
| +44 166670 | Protected | — |
| +44 1666710 | Allocated | Digitech Solutions Global Limited |
| +44 1666711 | Allocated | Calltracks Limited |
| +44 1666712 | Allocated | Atomstream Limited |
| +44 1666713 | Allocated | Telephone Box Limited |
| +44 1666714 | Allocated | VoiceHost Limited |
| +44 1666715 | Allocated | Windsor Telecom Limited |
| +44 1666716 | Allocated | Telappliant Limited |
| +44 1666717 | Allocated | Suretec Systems Ltd |
| +44 1666718 | Allocated | GCI Network Solutions Limited |
| +44 1666719 | Allocated | Simwood eSMS Limited |
| +44 1666720 | Protected | — |
| +44 1666721 | Allocated | Phone Co-Op Numbering Limited |
| +44 1666722 | Protected | — |
| +44 1666723 | Allocated | Invosys Limited |
| +44 1666724 | Allocated | INTELLIGENT EXCHANGES LIMITED |
| +44 1666725 | Protected | — |
| +44 1666726 | Allocated | Bicom Systems EURL |
| +44 1666727 | Allocated | Invoco Ltd |
| +44 1666728 | Allocated | 8x8 Communications UK Limited |
| +44 1666729 | Allocated | ICC Networks Ltd |
| +44 1666730 | Allocated | Content Guru Limited |
| +44 1666731 | Allocated | Ziron Limited |
| +44 1666732 | Protected | — |
| +44 1666733 | Allocated | Media Hawk Ltd |
| +44 1666734 | Allocated | Kalnet4U Ltd |
| +44 1666735 | Allocated | Nuso Cloud UK Limited |
| +44 1666736 | Allocated | IOVOX Limited |
| +44 1666737 | Allocated | Redwood Technologies Ltd |
| +44 1666738 | Allocated | GCI Network Solutions Limited |
| +44 1666739 | Allocated | XoverX Ltd |
Related lookups
- 01249 Chippenham14 km away
- 01285 Cirencester17 km away
- 01453 Dursley20 km away
- 01454 Chipping Sodbury21 km away
- BT10 allocated blocks on 01666
- Vodafone Ltd (C&W)8 allocated blocks on 01666
- GCI Network Solutions Limited3 allocated blocks on 01666
- All UK towns A–ZDialling codes by town
- More Wiltshire codesSame region
- All UK area codesBrowse every 01/02 dialling code
- Lookup any UK numberFree reverse phone lookup
- UK area codes explainedCornerstone guide
- 020 London numbers explainedCornerstone guide
- 0330 numbers explainedCornerstone guide
- How Ofcom allocates UK phone numbersCornerstone guide
FAQs about 01666
Where is area code 01666?
01666 is Ofcom's Malmesbury numbering area, in Wiltshire, South West England. Its exchange town is in Wiltshire. From abroad, drop the 0 and dial +44 1666.
Do I need to dial 01666 for a local call?
Traditionally not from another 01666 landline, but it now depends on your provider: Ofcom stopped requiring providers to offer local (code-free) dialling on 11 March 2022. Dialling 01666 first always works, and mobiles always need it.
How are 01666 numbers written?
Numbers on 01666 use Ofcom's 4+6 format: the 5-digit code (including the leading 0) followed by a 6-digit local number — written like 01666 234 567. From abroad the leading zero is dropped: +44 1666 then the local number.
What was the 01666 area code before?
01666 took its current form at PhONEday on 16 April 1995, when a "1" was inserted into every UK geographic code — before that the area dialled 0666. Old signage or stationery showing 0666 refers to the same Malmesbury numbers.
Which phone companies hold 01666 numbers?
Ofcom lists 88 providers with allocated blocks on 01666. The largest are BT with 10 of the 110 allocated blocks, Vodafone with 8 of the 110 allocated blocks and GCI Network Solutions Limited with 3 of the 110 allocated blocks. Numbers can be ported, so a number's current provider may differ from the block's holder.
Which area codes are next to 01666?
By distance between exchange towns, the nearest other codes are 01249 Chippenham (14 km), 01285 Cirencester (17 km), 01453 Dursley (20 km) and 01454 Chipping Sodbury (21 km).
How do I report a scam call from a 01666 number?
On a mobile, text the caller's number to 7726 (free). If you lost money or shared details, call your bank and report it to Report Fraud (0300 123 2040), which replaced Action Fraud in December 2025. Unwanted sales calls go to the ICO after registering with the Telephone Preference Service.