Porting a UK phone number: how it works

What you need

• A recent bill showing the account number and billing address exactly as registered
• The full list of numbers or number ranges to move
• The registered account name, matched character for character

Mismatched details are the most common reason a port is rejected.

Timelines

A single geographic number usually completes in around two weeks. Number ranges and multi-site estates take longer. You agree a date up front, and the cutover itself happens in a short window on that day.

Avoiding downtime

Never cancel the old service first — cancelling can release the number permanently. Build the new system on a temporary number, test it, then port. Keep a divert to a mobile ready as a safety net for the cutover window.