- Prefix
020 3- Area
- London
- Number type
- Geographic landline (01/02)
- Format
020 3XXX XXXX- From abroad
+44 20 3XXX XXXX- Ofcom blocks in range
- 1,000
- Blocks in service
- 925
- Range holders
- 174
What are 020 3XXX XXXX numbers?
Any UK number matching 020 3XXX XXXX sits in the
020 dialling code for London.
Ofcom hands these numbers to communications providers in blocks; this range
contains 1,000 blocks, of which
925 are allocated and usable. Calls from these
numbers are typically homes and businesses in the London area — or
organisations elsewhere that keep a local 020 presence using
VoIP.
Who holds 020 3… number ranges?
| Range holder (allocated by Ofcom) | Number blocks | Example range |
|---|---|---|
| BT | 230 | 020 3007 XXXX |
| Gamma Telecom Holdings Limited | 137 | 020 3002 XXXX |
| Colt Technology Services | 76 | 020 3003 XXXX |
| Sky UK Limited | 56 | 020 3015 XXXX |
| Verizon UK Limited | 42 | 020 3008 XXXX |
| Vodafone Ltd (C&W) | 37 | 020 3063 XXXX |
| TalkTalk Communications Limited | 31 | 020 3092 XXXX |
| Magrathea Telecommunications Limited | 17 | 020 3051 XXXX |
| GCI Network Solutions Limited | 11 | 020 3020 XXXX |
| Resilient Limited | 11 | 020 3162 XXXX |
| Virgin Media Limited | 11 | 020 3028 XXXX |
| Lumen Technologies UK Limited | 9 | 020 3014 XXXX |
…and 162 more providers hold smaller allocations in this range.
Ofcom’s data shows the provider each number range was originally allocated to — not who holds an individual number today. Numbers are frequently moved (ported) between providers, and no public database reveals the person or business behind a specific number, so treat any service that claims to with suspicion.
Not every block in this range is in service: of the 1,000 blocks Ofcom lists, 73 are protected (reserved by Ofcom and not in use) and 2 are free/unallocated. A call appearing to come from an unallocated block is a strong sign of a spoofed number.
Is a call from a 020 3… number safe?
A local-looking number is never proof of who is calling: fraudsters spoof 020 caller IDs so their calls look like they come from London (‘neighbour spoofing’). If an unexpected caller asks for personal, banking or one-time-code details, hang up and ring the organisation back on a number you find independently. To put a name to a caller, see who called me?; to report one, see how to report a scam number.
Check a specific 020 3XXX XXXX number
Paste any full number into the checker above (or on the main phone number checker) to see its exact range holder and allocation status from this week’s Ofcom data.
Run mobiles for a business? See our business mobile network comparison or get a quote.