01245 Area Code — Chelmsford, Writtle & Boreham
01245 is the UK dialling code for Chelmsford in Essex, also serving Writtle, Boreham and Stock, allocated by Ofcom under the National Telephone Numbering Plan. Our database has tracked 342 distinct 01245 numbers across 478 public lookups.
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Quick facts
Area code
01245
Location
Chelmsford
County
Essex
Region
East of England
Number type
Geographic landline
Number format
01245 XXX XXX
Operators serving
8+
Call cost
Standard rate
About the 01245 dialling code
01245 is the UK geographic dialling code for Chelmsford, allocated by Ofcom under the National Telephone Numbering Plan. It is used by landlines — and increasingly VoIP lines — registered to the Chelmsford area.
A full Chelmsford number is normally written as 01245 XXXXXX. You can dial the local part on its own from within the same area, or the full number from anywhere in the UK.
Because of UK number portability and internet calling, a 01245 number no longer guarantees the caller is physically in Chelmsford. Fraudsters also "spoof" local codes like 01245 so an unknown call looks like a nearby business or neighbour — so treat an unexpected call on what is actually said, not on the area code alone.
Map of the 01245 dialling area
The marker shows Chelmsford; the shaded circle is an approximate indication of the area the 01245 code serves — exact Ofcom charging-area boundaries are irregular and don't follow a neat radius.
Map data © OpenStreetMap contributors. View larger map
Areas typically served by 01245
Settlements in and around the Chelmsford dialling area that typically use 01245 numbers. Approximate — Ofcom charging-area boundaries don't follow town or county lines exactly, and properties near a boundary may take a neighbouring code.
Calling 01245 from abroad
From outside the UK, dial your international access prefix, then the UK country code 44, then 1245 (the area code without its leading zero) and the local number.
| Calling from | Dial |
|---|---|
| United States & Canada | 011 44 1245 … |
| Europe / most of the world | 00 44 1245 … |
| Australia | 0011 44 1245 … |
| Any mobile phone | +44 1245 … |
History of the 01245 code
The code was 0245 until PhONEday, 16 April 1995, when a "1" was inserted after the leading zero to create 01245.
In the letter-dialling era the code had the mnemonic CH5 — on an old rotary dial, the letters CH (from Chelmsford) sat on the same holes as the digits 245, so subscribers literally dialled the start of the town's name.
Top searched 01245 numbers
These are the 01245 numbers most-looked-up by visitors to our number checker. Click any number to see its full lookup page with risk-level, range holder, and community reports.
| Number | Searches | Last looked up |
|---|---|---|
| 01245 981427 | 9 | 9 Jul 2026 |
| 01245 823151 | 8 | 9 Jul 2026 |
| 01245 921438 | 7 | 9 Jul 2026 |
| 01245 981426 | 7 | 6 Jul 2026 |
| 01245 936138 | 7 | 3 Jul 2026 |
| 01245 343999 | 7 | 11 Jun 2026 |
| 01245 934767 | 6 | 9 Jul 2026 |
| 01245 974476 | 5 | 7 Jul 2026 |
| 01245 969050 | 5 | 7 Jul 2026 |
| 01245 611328 | 5 | 23 Jun 2026 |
| 01245 821077 | 4 | 2 Jul 2026 |
| 01245 373692 | 4 | 2 Jul 2026 |
| 01245 46222 | 4 | 25 Jun 2026 |
| 01245 821079 | 4 | 21 Jun 2026 |
| 01245 210080 | 4 | 16 Jun 2026 |
| 01245 904168 | 4 | 9 Jun 2026 |
| 01245 904992 | 4 | 5 Jun 2026 |
| 01245 821074 | 3 | 11 Jul 2026 |
| 01245 373590 | 3 | 10 Jul 2026 |
| 01245 821075 | 3 | 8 Jul 2026 |
Is a call from 01245 safe?
Most 01245 calls are ordinary local calls from Chelmsford homes and businesses. The main risk to be aware of is "neighbour spoofing", where a scammer fakes a local 01245 prefix so you are more likely to answer. Never share bank details, passwords or one-time security codes with an unexpected caller, even when the number looks local — hang up and call the organisation back on a number you have verified yourself.
To call a 01245 (Chelmsford) number from outside the UK, drop the leading zero and dial +44 1245 followed by the local number.
Operators serving Chelmsford
These UK communications providers have been allocated 01245 number blocks by Ofcom. The number of blocks per operator gives a rough sense of how widely each provider serves this area.
| Provider (Ofcom-allocated) | Allocated blocks |
|---|---|
| BT | 36 |
| Gamma Telecom Holdings Limited | 17 |
| Sky UK Limited | 15 |
| Virgin Media Limited | 13 |
| Vodafone Ltd (C&W) | 10 |
| Magrathea Telecommunications Limited | 8 |
| TalkTalk Communications Limited | 8 |
| Colt Technology Services | 6 |
Ofcom number ranges on 01245
Ofcom's National Numbering Plan lists 388 number blocks under 01245, of which 247 are allocated to 116 communications providers. The first allocated blocks are shown below — look up any full number with the number checker to see its exact range holder.
| Number block | Status | Range holder (Ofcom-allocated) |
|---|---|---|
0124500… | Allocated | Barritel Limited |
0124514… | Allocated | Virgin Media Limited |
0124520… | Allocated | Gamma Telecom Holdings Limited |
0124521… | Allocated | BT |
0124522… | Allocated | BT |
0124523… | Allocated | BT |
0124524… | Allocated | BT |
0124525… | Allocated | BT |
0124526… | Allocated | BT |
0124527… | Allocated | BT |
0124528… | Allocated | BT |
0124529… | Allocated | BT |
Showing 12 of 247 allocated blocks. Source: Ofcom telephone numbering data, updated weekly.
Common scam patterns reported in Chelmsford
Categories most-commonly tagged on user-submitted reports for 01245 numbers in our community comments.
- telemarketing — 1 report
How to block and report 01245 spam calls
Block or report 01245
- You can block 01245 directly from your recent-calls list on iPhone or Android, and forward scam texts free to 7726.
- Scam or fraud calls should be reported to Action Fraud (0300 123 2040) or Police Scotland (101); persistent marketing calls to the ICO / TPS.
Full step-by-step instructions for every phone, network-level blocking and all UK reporting routes are in our guide: How to block and report unwanted calls in the UK.
How to stop unwanted calls for good
Blocking 01245 numbers stops that one number, but determined nuisance callers simply switch numbers. Silencing unknown callers, enabling your network's free spam shield and registering with the TPS cut the volume across the board — our canonical guide walks through each step: How to block and report unwanted calls in the UK.
Frequently asked questions about the 01245 code
Where is the 01245 area code?
The 01245 area code is allocated by Ofcom to Chelmsford in Essex, United Kingdom. It is a geographic UK landline dialling code under the National Telephone Numbering Plan. The surrounding dialling area also takes in Writtle, Boreham, Stock and nearby villages.
Is 01245 always a Chelmsford number?
Numbers with the 01245 prefix were originally allocated by Ofcom to Chelmsford. With UK number portability and VoIP allowing geographic relocation while keeping the same number, the call origin can differ from the original area, but the prefix's official assigned location remains Chelmsford.
How do I block 01245 spam calls?
On iPhone, tap the (i) next to the number in Recents and choose Block this Caller. On Android, long-press the number in Recents and choose Block. To prevent unknown 01245 numbers ringing, enable Settings → Phone → Silence Unknown Callers (iPhone) or your dialler's spam filter (Android). Forward spam texts to 7726 free of charge.
How much does a 01245 call cost?
Calls to UK 01245 geographic numbers are charged at your provider's standard rate and are usually included in inclusive minutes on any modern landline or mobile plan.
Neighbouring dialling codes
Codes covering areas around Chelmsford — useful when a caller is nearby but outside the 01245 boundary.
Living in or moving to Chelmsford?
Our free postcode reports cover house prices, crime, broadband and schools for the districts around Chelmsford.
Check another UK number
Have the full 10- or 11-digit number? The UK Phone Number Checker shows the Ofcom range holder, risk level, and any community reports for that specific number.