Keep your number when you switch: UK porting in plain terms

Your number is on the van. It's on the website, the Google listing, the bottom of ten thousand emails, and saved in the phones of customers who've been calling you for years. Change it and some of them just never reach you again.

So when the service behind that number turns bad, dropped calls, a provider who won't pick up, a bill that creeps every quarter, plenty of UK businesses stay put anyway. Not because the service is good. Because they think switching means losing the number.

It doesn't. Moving your number to a new provider is called porting, and business number porting in the UK is a routine, regulated process. We UC has done it thousands of times over fifteen years. Here's how it actually works, in plain terms.

If you're moving because your old analogue or ISDN line is being retired, this is one part of a bigger move - see our guide to the 2027 PSTN switch-off for the full picture.

What porting actually means

Porting is moving an existing phone number from one provider to another and keeping the number exactly as it is. Same digits, new network behind them.

There are two sides to every port. The losing provider is whoever you're with now. The gaining provider is the one you're moving to. The gaining provider does most of the legwork: you tell them the number you want to bring, and they arrange it with the losing provider.

The number is yours to take. Ofcom obliges UK providers to let you port out, so your current provider can't hold it hostage to keep you. It works for mobiles, for landline and geographic numbers (your 01s and 02s), and for 03 numbers too.

The number stays. Only the network behind it changes.

How long it really takes

This is the part people worry about most, and it depends almost entirely on the type of number.

Mobile is the simplest. You text the word PAC to 65075, your provider sends back a porting authorisation code, you hand that code to the new provider, and the number usually moves the next working day.

Landline and geographic numbers take longer. There's no PAC for these. Instead the gaining provider raises a porting request with the losing provider, backed by a Letter of Authority and usually a recent bill to prove the account is yours. A clean single-number port is typically a couple of weeks; larger ranges and numbers bundled with other services take longer.

Why the gap? Mobile porting was streamlined years ago. Fixed-line porting still runs through older, more cautious processes with more checks along the way.

Here's the thing worth holding onto: that timeline is mostly waiting, not downtime. Your old service keeps working the whole time. Nothing goes dark while the paperwork moves.

The day of the cutover

Porting happens at a scheduled date, often within a set window on that day. It isn't a leap of faith. It's a calendar entry.

The way to do it without drama is parallel running. You set up the new service first, test that it makes and takes calls properly, and only then port the number across. Your old line stays live right up until the number moves.

On cutover, calls to your number stop landing on the old network and start landing on the new one. The switch itself is quick. At any given moment the number is live on one network or the other, never floating in between, so a planned port doesn't drop calls.

Done properly, the only thing your customers notice is nothing.

Where ports actually go wrong

When a port goes sideways, it's almost never the technology. It's admin. These are the snags we see, and all of them are avoidable.

• Cancelling the old service first. This is the big one. Cancel your account before the port completes and you can lose the number entirely, because there's nothing left for the port to pull from. Never cancel first. Let the port complete, then close the old account.
• Mismatched details. If the name, address or account number on the request doesn't match the losing provider's records, the port gets rejected. Pull a recent bill and copy the details exactly as they appear.
• A number tied to your broadband. If your number rides on a line that also carries your internet, moving the number can cease the broadband. Worth checking and sequencing before you start.
• Outstanding contract or notice. This won't usually block the port, but you may still owe your old provider for any remaining term. No surprise, just worth knowing.

A provider who's done this before catches every one of these up front, before the request is ever raised.

Why we're calm about this

Fifteen years in UK telecoms teaches you that porting is boring when you know it. We UC has ported thousands of numbers for UK businesses, on our own infrastructure, bootstrapped, no outside money. We've seen every snag on that list more times than we can count, which is exactly why they don't trip us up.

That's the whole reason we talk about it plainly. The fear of losing your number is the single thing keeping good operators stuck with phone service they quietly hate. It's a fear built on a misunderstanding.

With Olatti, your existing number comes with you. You carry it on the same phone you already use, and reaching someone goes back to being one quick keystroke instead of a chore. The number you've spent years building stays exactly where it is. The service around it gets a lot better.

Your number was never the reason to stay.

Olatti is opening to a founding group of UK teams. If you'd like to keep your number and finally enjoy your business calls again, join the waitlist, and we'll walk you through the port when you're in.