Your numbers are yours by law. Here’s how taking them with you actually works — and the two traps that catch businesses out.
You don’t port a number yourself — your new provider does it for you. To port a business phone number, you order service from the new provider, give them the numbers you want to keep, and they lead the transfer; your old provider must cooperate and cannot charge you for the port. Number portability is a legal right for UK businesses of any size. The one rule that matters above all: port first, while the old service is still live — then terminate.
Trap one: terminating first. If you cancel the old account before porting, the numbers can be released — and although the rules keep them portable for at least a month after termination, recovering a released number is exactly the drama you’re trying to avoid. Keep the old service alive until the port has completed.
Trap two: assuming the port ends the contract. It doesn’t. Porting moves the numbers; the contract carries on until you end it properly — notice period, minimum term and all. Port and exit are two separate steps: see Can you cancel a business phone contract? for the exit routes, and how to leave without paying a fee for the evidence and sequence.
For business mobile numbers on accounts with fewer than 25 numbers, the consumer-style text codes apply: text PAC to 65075 to move a number, and your new provider completes it within one working day. Larger fleets are migrated contractually with the new provider — same outcome, more coordination.
The One Touch Switch process — where your new provider handles the entire switch including ending the old contract — is a residential-only right. A business coordinates the port and the exit separately. This is exactly the kind of work a managed provider does for you: at Zen, number porting is a standard part of the 4-Step Easy Migration, planned so there’s no downtime and nothing changes for your callers until the moment of cutover.
Yes — partial ports are normal. List exactly which numbers move on the port order, and confirm what happens to any you’re leaving behind, because numbers left on a closing account can be lost.
Done properly, no. Calls keep landing on the old service right up to the cutover moment, and on the new service after it. There’s no in-between gap when a port is scheduled and managed correctly.
They’re not allowed to obstruct a port — the rules make porting a duty, ban charging you for it, and entitle you to compensation for failures and delays. If your business has 10 or fewer people, an unresolved porting complaint can also go to the free ombudsman — see [the six-week rule](https://app.notion.com/guides/phone-complaint-ombudsman-six-week-rule/).
Every claim above is drawn from the sources below, checked against the current published version.
Last verified 30 July 2026 · General information, not legal advice — your own solicitor should confirm how the rules apply to your case.
