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

Your number is on the van. It's on the website, on the Google listing, at the bottom of every email you've sent since you started, and saved in the phones of customers who've rung it for years. Lose it and some of those people never reach you again. So when the service behind it turns bad, a lot of UK businesses stay put rather than switch, because they believe moving provider means losing the number. It doesn't. Business number porting in the UK is routine and regulated, and I've sat next to the customer while it happened often enough to say so plainly.

Between 2015 and 2018 I did around 200 installs myself at circle.cloud, the UK telecoms company I started that installs and supports phone systems for small businesses, handling the sale, the port, the installation and the support on every one. The question that came up before price, nearly every time, was what happens to our number. This is the answer I gave then, and still give now.

Porting means moving your existing number to a new provider with the digits unchanged. Ofcom obliges UK providers to let you port out. A mobile number usually moves the next working day with a PAC code; landline and geographic numbers typically take a couple of weeks and a Letter of Authority. Your old line keeps working until the number moves.

If your line is being retired in the PSTN switch-off, the port is one piece of a bigger move. The 2027 switch-off guide covers the rest.

What does porting actually mean?

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, and they do most of the legwork: you tell them the number you want to bring, and they arrange the move with the losing side. Same digits, new network behind them.

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. That holds for mobiles, for landline and geographic numbers (your 01s and 02s), and for 03 numbers too.

The short version is the one customers actually need. The number stays. Only the network behind it changes.

How long does business number porting take in the UK?

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

Mobile is the simple one. 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.

The part worth holding onto: that timeline is waiting, not downtime. Your old line keeps ringing the whole way through. Nothing goes dark while the paperwork moves.

What happens on the day of the cutover?

Porting happens on a scheduled date, usually within a set window that day. It's a calendar entry, not a leap of faith.

The way to do it without drama is parallel running. New service in first, tested properly making and taking calls, and only then the port. The old line stays live right up until the number moves, so if the new kit has a problem you find it on a day when nothing depends on it.

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 side 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 do ports go wrong?

When a port goes wrong it's almost never the technology. It's admin. These are the four things we check before a request is ever raised, because a rejected request means starting the clock again.

• Cancelling the old service first. 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. 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, down to the trading name.
• A number tied to your broadband. If your number rides on the line that also carries your internet, moving the number can cease the broadband. Check it and sequence it before you start.
• Outstanding contract or notice. This won't usually block the port, but you may still owe your old provider for the remaining term. No surprise, just worth knowing before you sign.

A provider who's done this before catches all four before the form goes in.

Why I'm calm about this

I've been selling and installing business phone systems since 2012, the last decade of it at circle.cloud. Porting was the part of every install the customer dreaded, and the part I'd stopped worrying about long before they had.

That's the whole reason I talk about it plainly. Most of the businesses I met who were putting up with bad service weren't staying for the service. They were staying for the number. And the number was never at risk.

With Olatti, your existing number comes with you: £20 per number to bring it across, one-off, then £5 a month, and we do the paperwork with your old provider. It reaches you on the desk phone, on the desktop or on the phone in your pocket, and calling someone back is a couple of keystrokes rather than 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. It's on the van, and it can stay on the van.

Olatti is open to UK teams. If you'd like to bring your number with you and enjoy your business calls again, try for free (opens in a new tab), and we'll walk you through the port when you're in.