UK area code
01833 area code — Barnard Castle
01833 is Ofcom’s Barnard Castle numbering area, in Durham, North East England. 85 phone companies hold its 104 allocated number blocks. Its numbers are written like 01833 234 567. The nearest other codes are 01748 Richmond (20 km) and 01388 Bishop Auckland (23 km).
01833 at a glance
- Ofcom area name
- Barnard Castle
- County
- Durham
- Council area
- County Durham
- Region
- North East England
- Number format
- 01833 234 567 (4+6)
- Local calls
- Full number recommended
- Current code since
- 1995 (previously 0833)
- Allocated blocks
- 104 of 424 (25%) across 85 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 01833 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.
01833 history and number format
Number format: Numbers on 01833 use Ofcom's 4+6 format: the 5-digit code (including the leading 0) followed by a 6-digit local number — written like 01833 234 567.
Before 1995: 01833 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 0833.
Local dialling: Traditionally not from another 01833 landline, but it now depends on your provider: Ofcom stopped requiring providers to offer local (code-free) dialling on 11 March 2022. Dialling 01833 first always works, and mobiles always need it.
Allocation record: the oldest number block still visible on 01833 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 01833 number rings (see the weekly numbering changelog for every new allocation.)
Phone companies holding 01833 numbers
Every Ofcom range holder with blocks on 01833, 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 |
|---|---|---|---|---|
| GCI Network Solutions Limited | 11 | 11 | 2 May 2017 | 26 February 2024 |
| BT | 8 | 8 | 15 July 1994 | 21 July 2021 |
| Fuse 2 Communications Ltd | 2 | 2 | 3 July 2017 | 22 January 2024 |
| TalkTalk Communications Limited | 2 | 2 | 20 January 2012 | 20 January 2012 |
| (AQ) LIMITED | 1 | 1 | 26 September 2012 | 26 September 2012 |
| 24 Seven Cloud Communications Ltd | 1 | 1 | 13 January 2020 | 13 January 2020 |
| 8x8 Communications UK Limited | 1 | 1 | 18 April 2012 | 18 April 2012 |
| AQL Wholesale Ltd | 1 | 1 | 3 January 2008 | 3 January 2008 |
| Adepteo Limited | 1 | 1 | 6 December 2016 | 6 December 2016 |
| Andrews & Arnold (Numbers) Ltd | 1 | 1 | 2 April 2009 | 2 April 2009 |
| Atomstream Limited | 1 | 1 | 14 May 2010 | 14 May 2010 |
| Barritel Limited | 1 | 1 | 2 October 2006 | 2 October 2006 |
| Belgacom International Carrier Services SA | 1 | 1 | 3 October 2019 | 3 October 2019 |
| Bicom Systems EURL | 1 | 1 | 1 March 2012 | 1 March 2012 |
| Bink Networks Ltd | 1 | 1 | 27 March 2023 | 27 March 2023 |
| CFL Communications Ltd | 1 | 1 | 17 July 2009 | 17 July 2009 |
| Calltracks Limited | 1 | 1 | 22 January 2014 | 22 January 2014 |
| Colt Technology Services | 1 | 1 | 20 June 2016 | 20 June 2016 |
| Content Guru Limited | 1 | 1 | 11 October 2012 | 11 October 2012 |
| Convergence Group (wireless) Networks Limited | 1 | 1 | 21 May 2019 | 21 May 2019 |
| DIDWW Ireland Limited | 1 | 1 | 27 January 2020 | 27 January 2020 |
| DRD Communications Limited | 1 | 1 | 5 October 2023 | 5 October 2023 |
| Dial 9 Communications Limited | 1 | 1 | 8 January 2020 | 8 January 2020 |
| Digital Space Group Limited | 1 | 1 | 23 May 2008 | 23 May 2008 |
| Digitech Solutions Global Limited | 1 | 1 | 22 June 2012 | 22 June 2012 |
| EVE CONNECT LTD | 1 | 1 | 20 June 2022 | 20 June 2022 |
| Flextel Limited | 1 | 1 | 26 October 2005 | 26 October 2005 |
| Gamma Telecom Holdings Limited | 1 | 1 | 16 May 2005 | 16 May 2005 |
| Hello Telecom (UK) Limited | 1 | 1 | 23 November 2011 | 23 November 2011 |
| I.T Communications Limited | 1 | 1 | 20 November 2015 | 20 November 2015 |
Showing the 30 largest of 85 holders.
All number blocks on 01833first 200 of 424, by prefix
| Prefix | Status | Range holder |
|---|---|---|
| +44 183300 | Protected | — |
| +44 183301 | Protected | — |
| +44 183302 | Protected | — |
| +44 183303 | Protected | — |
| +44 183304 | Protected | — |
| +44 183305 | Protected | — |
| +44 183306 | Protected | — |
| +44 183307 | Protected | — |
| +44 183308 | Protected | — |
| +44 183309 | Protected | — |
| +44 183310 | Protected | — |
| +44 183311 | Protected | — |
| +44 183312 | Protected | — |
| +44 183313 | Protected | — |
| +44 183314 | Protected | — |
| +44 183315 | Protected | — |
| +44 183316 | Protected | — |
| +44 183317 | Protected | — |
| +44 183318 | Protected | — |
| +44 183319 | Protected | — |
| +44 183320 | Allocated | AQL Wholesale Ltd |
| +44 183321 | Allocated | Lumen Technologies UK Limited |
| +44 183322 | Allocated | Net-Work Internet Ltd |
| +44 183323 | Allocated | Redcentric Solutions Limited |
| +44 183324 | Allocated | Telecom2 Limited |
| +44 183325 | Allocated | Digital Space Group Limited |
| +44 183326 | Allocated | Nodemax Limited |
| +44 183327 | Protected | — |
| +44 1833280 | Allocated | Voxbone SA |
| +44 1833281 | Protected | — |
| +44 1833282 | Protected | — |
| +44 1833283 | Protected | — |
| +44 1833284 | Protected | — |
| +44 1833285 | Protected | — |
| +44 1833286 | Protected | — |
| +44 1833287 | Protected | — |
| +44 1833288 | Protected | — |
| +44 1833289 | Protected | — |
| +44 183329 | Allocated | Served Up Limited |
| +44 1833300 | Protected | — |
| +44 1833301 | Protected | — |
| +44 1833302 | Protected | — |
| +44 1833303 | Protected | — |
| +44 1833304 | Allocated | Six Degrees Technology Group Limited |
| +44 1833305 | Protected | — |
| +44 1833306 | Protected | — |
| +44 1833307 | Protected | — |
| +44 1833308 | Protected | — |
| +44 1833309 | Protected | — |
| +44 1833310 | Allocated | Linear Telecoms Limited |
| +44 1833311 | Allocated | ICC Networks Ltd |
| +44 1833312 | Allocated | 8x8 Communications UK Limited |
| +44 1833313 | Allocated | Invoco Ltd |
| +44 1833314 | Allocated | IOVOX Limited |
| +44 1833315 | Protected | — |
| +44 1833316 | Allocated | Sky UK Limited |
| +44 1833317 | Allocated | Ziron Limited |
| +44 1833318 | Protected | — |
| +44 1833319 | Allocated | Content Guru Limited |
| +44 183332 | Allocated | Flextel Limited |
| +44 1833330 | Allocated | GCI Network Solutions Limited |
| +44 1833331 | Allocated | GCI Network Solutions Limited |
| +44 1833332 | Allocated | GCI Network Solutions Limited |
| +44 1833333 | Allocated | GCI Network Solutions Limited |
| +44 1833334 | Allocated | GCI Network Solutions Limited |
| +44 1833335 | Allocated | GCI Network Solutions Limited |
| +44 1833336 | Allocated | GCI Network Solutions Limited |
| +44 1833337 | Allocated | GCI Network Solutions Limited |
| +44 1833338 | Allocated | GCI Network Solutions Limited |
| +44 1833339 | Allocated | GCI Network Solutions Limited |
| +44 183334 | Allocated | Magrathea Telecommunications Limited |
| +44 183335 | Allocated | BT |
| +44 1833360 | Allocated | Digitech Solutions Global Limited |
| +44 1833361 | Allocated | Nexbridge Communications Limited |
| +44 1833362 | Allocated | Convergence Group (wireless) Networks Limited |
| +44 1833363 | Allocated | YayYay Limited |
| +44 1833364 | Allocated | Internexus Networks Limited |
| +44 1833365 | Allocated | Bicom Systems EURL |
| +44 1833366 | Protected | — |
| +44 1833367 | Allocated | Inet Telecoms Ltd (Voipfone) |
| +44 1833368 | Allocated | Hello Telecom (UK) Limited |
| +44 1833369 | Allocated | Minotaur Telecom Limited |
| +44 1833370 | Protected | — |
| +44 1833371 | Protected | — |
| +44 1833372 | Protected | — |
| +44 1833373 | Protected | — |
| +44 1833374 | Protected | — |
| +44 1833375 | Protected | — |
| +44 1833376 | Protected | — |
| +44 1833377 | Protected | — |
| +44 1833378 | Protected | — |
| +44 1833379 | Protected | — |
| +44 183338 | Allocated | GCI Network Solutions Limited |
| +44 1833390 | Allocated | VoiceHost Limited |
| +44 1833391 | Allocated | Orange Business Holdings UK Limited |
| +44 1833392 | Free | — |
| +44 1833393 | Allocated | KCOM Group Ltd |
| +44 1833394 | Free | — |
| +44 1833395 | Free | — |
| +44 1833396 | Allocated | Bink Networks Ltd |
| +44 1833397 | Free | — |
| +44 1833398 | Free | — |
| +44 1833399 | Free | — |
| +44 183340 | Allocated | Solutios Limited |
| +44 183341 | Allocated | Mars Communications Limited |
| +44 183342 | Protected | — |
| +44 183343 | Quarantined | — |
| +44 183344 | Allocated | Andrews & Arnold (Numbers) Ltd |
| +44 183345 | Allocated | Telecoms World Limited |
| +44 183346 | Allocated | CFL Communications Ltd |
| +44 183347 | Quarantined | — |
| +44 183348 | Protected | — |
| +44 183349 | Allocated | Nexus Telecommunications Limited |
| +44 183350 | Protected | — |
| +44 1833510 | Allocated | Calltracks Limited |
| +44 1833511 | Allocated | Windsor Telecom Limited |
| +44 1833512 | Allocated | Atomstream Limited |
| +44 1833513 | Allocated | Telephone Box Limited |
| +44 1833514 | Protected | — |
| +44 1833515 | Allocated | Suretec Systems Ltd |
| +44 1833516 | Allocated | Phone Co-Op Numbering Limited |
| +44 1833517 | Allocated | Invosys Limited |
| +44 1833518 | Allocated | INTELLIGENT EXCHANGES LIMITED |
| +44 1833519 | Protected | — |
| +44 1833520 | Protected | — |
| +44 1833521 | Allocated | Adepteo Limited |
| +44 1833522 | Allocated | Colt Technology Services |
| +44 1833523 | Allocated | I.T Communications Limited |
| +44 1833524 | Allocated | IP Voice Networks Ltd |
| +44 1833525 | Protected | — |
| +44 1833526 | Allocated | Mintaka Limited |
| +44 1833527 | Allocated | Orbtalk Limited |
| +44 1833528 | Allocated | Zapappi Ltd |
| +44 1833529 | Allocated | Belgacom International Carrier Services SA |
| +44 1833530 | Allocated | Nuso Cloud UK Limited |
| +44 1833531 | Allocated | Fuse 2 Communications Ltd |
| +44 1833532 | Allocated | Kalnet4U Ltd |
| +44 1833533 | Allocated | Simwood eSMS Limited |
| +44 1833534 | Allocated | Number Services Ltd. |
| +44 1833535 | Allocated | Redwood Technologies Ltd |
| +44 1833536 | Allocated | Fuse 2 Communications Ltd |
| +44 1833537 | Allocated | XoverX Ltd |
| +44 1833538 | Protected | — |
| +44 1833539 | Protected | — |
| +44 1833540 | Allocated | Dial 9 Communications Limited |
| +44 1833541 | Allocated | 24 Seven Cloud Communications Ltd |
| +44 1833542 | Allocated | DIDWW Ireland Limited |
| +44 1833543 | Allocated | SiPalto Ltd |
| +44 1833544 | Allocated | EVE CONNECT LTD |
| +44 1833545 | Allocated | ICUK Computing Services Limited |
| +44 1833546 | Allocated | Mi Telecom Limited |
| +44 1833547 | Allocated | VOXYONDER NETWORK SERVICES UK LTD |
| +44 1833548 | Free | — |
| +44 1833549 | Allocated | BT |
| +44 1833550 | Protected | — |
| +44 1833551 | Protected | — |
| +44 1833552 | Protected | — |
| +44 1833553 | Protected | — |
| +44 1833554 | Protected | — |
| +44 1833555 | Protected | — |
| +44 1833556 | Protected | — |
| +44 1833557 | Protected | — |
| +44 1833558 | Protected | — |
| +44 1833559 | Protected | — |
| +44 1833560 | Protected | — |
| +44 1833561 | Protected | — |
| +44 1833562 | Protected | — |
| +44 1833563 | Protected | — |
| +44 1833564 | Protected | — |
| +44 1833565 | Protected | — |
| +44 1833566 | Protected | — |
| +44 1833567 | Protected | — |
| +44 1833568 | Protected | — |
| +44 1833569 | Protected | — |
| +44 1833570 | Protected | — |
| +44 1833571 | Protected | — |
| +44 1833572 | Protected | — |
| +44 1833573 | Protected | — |
| +44 1833574 | Protected | — |
| +44 1833575 | Protected | — |
| +44 1833576 | Protected | — |
| +44 1833577 | Protected | — |
| +44 1833578 | Protected | — |
| +44 1833579 | Protected | — |
| +44 1833580 | Protected | — |
| +44 1833581 | Protected | — |
| +44 1833582 | Protected | — |
| +44 1833583 | Protected | — |
| +44 1833584 | Protected | — |
| +44 1833585 | Protected | — |
| +44 1833586 | Protected | — |
| +44 1833587 | Protected | — |
| +44 1833588 | Protected | — |
| +44 1833589 | Protected | — |
| +44 1833590 | Protected | — |
| +44 1833591 | Protected | — |
| +44 1833592 | Protected | — |
| +44 1833593 | Protected | — |
| +44 1833594 | Protected | — |
| +44 1833595 | Protected | — |
Related lookups
- 01748 Richmond20 km away
- 01388 Bishop Auckland23 km away
- 01325 Darlington24 km away
- 01740 Sedgefield25 km away
- GCI Network Solutions Limited11 allocated blocks on 01833
- BT8 allocated blocks on 01833
- Fuse 2 Communications Ltd2 allocated blocks on 01833
- All UK towns A–ZDialling codes by town
- More County Durham 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 01833
Where is area code 01833?
01833 is Ofcom's Barnard Castle numbering area, in Durham, North East England. Its exchange town is in County Durham. From abroad, drop the 0 and dial +44 1833.
Do I need to dial 01833 for a local call?
Traditionally not from another 01833 landline, but it now depends on your provider: Ofcom stopped requiring providers to offer local (code-free) dialling on 11 March 2022. Dialling 01833 first always works, and mobiles always need it.
How are 01833 numbers written?
Numbers on 01833 use Ofcom's 4+6 format: the 5-digit code (including the leading 0) followed by a 6-digit local number — written like 01833 234 567. From abroad the leading zero is dropped: +44 1833 then the local number.
What was the 01833 area code before?
01833 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 0833. Old signage or stationery showing 0833 refers to the same Barnard Castle numbers.
Which phone companies hold 01833 numbers?
Ofcom lists 85 providers with allocated blocks on 01833. The largest are GCI Network Solutions Limited with 11 of the 104 allocated blocks, BT with 8 of the 104 allocated blocks and Fuse 2 Communications Ltd with 2 of the 104 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 01833?
By distance between exchange towns, the nearest other codes are 01748 Richmond (20 km), 01388 Bishop Auckland (23 km), 01325 Darlington (24 km) and 01740 Sedgefield (25 km).
How do I report a scam call from a 01833 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.