617 number blocks allocated by Ofcom
Total blocks
617
Mobile blocks
0
Network type
Fixed / virtual
| Number range | Blocks |
|---|---|
| 01 and 02 geographic | 612 |
| 03 UK-wide | 2 |
| 08 freephone and business rate | 2 |
| 055 and 056 corporate / VoIP | 1 |
No numbers have been checked here yet. Run a check above and this table will start filling up.
Ofcom does not hand out individual phone numbers. It allocates blocks — usually a thousand or ten thousand consecutive numbers at a time — to licensed communications providers, who then issue them to their own customers. So a number in a Atomstream Limited block was issued by Atomstream Limited, or by a reseller buying capacity from them.
The important caveat is porting. UK customers have a legal right to keep their number when they switch provider, and the number never leaves its original block when they do. That is why a lookup can confidently tell you which provider a range belongs to, but cannot tell you which network is serving a number today.
Ofcom has allocated 617 number blocks to Atomstream Limited. A block is typically 1,000 or 10,000 consecutive numbers, so the total pool runs into the millions. Allocation is not the same as usage — providers hold headroom for future customers.
Not necessarily. Ofcom's data tells you which provider a range was allocated to, not who is using an individual number, and caller ID can be spoofed. What it does prove is the opposite case: if a number sits outside any allocated range, no provider issued it and the call is definitely not genuine.
Because of number porting. When you switch provider and keep your number, the number stays inside the block Ofcom originally allocated. Any lookup based on Ofcom data will keep showing the original range holder, not your current network.