How to Switch Mobile Provider in the UK and Keep Your Number: The PAC Code Guide

Millions of people in the UK stay on expensive contracts long after the handset is paid off, simply because switching feels like a hassle. It is not. Since Ofcom's text-to-switch rules arrived, changing provider while keeping your number is one text message, one code, and about a day of waiting. This guide walks through the whole process, including the costs to watch for and the mistakes to avoid.

1. Check whether you are still in contract

Before anything else, find out if your current contract has time left to run. If you are within a minimum term, leaving early usually triggers an early termination fee. The cleanest moment to switch is when the handset is paid off or the contract has run its course. Most providers let you check your contract end date in their app or by texting INFO to 85075 for free, which also shows any charges that would apply if you leave now.

2. Pick your new deal and order the SIM

Shop around for SIM-only or contract deals from the new provider and order a SIM before you cancel anything with the old one. Your old service keeps running until the switch completes, so there is no gap where you have no service. Many people order the SIM a few days early so it is in hand when the transfer happens. In most cases you can insert it and start using it the same day the number moves across.

3. Text PAC to 65075 to get your code

This is the heart of the process. Text the word PAC to 65075 from the phone number you want to keep. Your current provider must reply with a Porting Authorisation Code, usually within minutes. The code is valid for 30 days, so you do not have to use it instantly. Do not let a retention call talk you into staying if you have already decided: the whole point of text-to-switch is that you can do it without a phone call.

4. Give the code to your new provider

Pass the PAC code to the new provider when you activate your SIM, usually in their app or on their website. They handle the transfer from there. The number normally moves across on the next working day. During the transfer you may lose service for a short window, often a couple of hours, so do it on a day when you can live with that.

5. Settle the final bill and check for fees

Once the switch completes, your old provider will send a final bill. If you were out of contract, this is usually just your last month's usage. If you left early, the termination charges appear here. Read it carefully and do not ignore it: unresolved bills from mobile providers can end up on your credit file. Set up or cancel the direct debit only after the final payment has cleared.

6. Update your two-factor logins and banks

This step is easy to forget. After your number moves, check that services sending you login codes still work. The number itself does not change, so in most cases everything continues silently. But if you switched from a physical SIM to an eSIM, or if anything glitched during transfer, test your banking app and any two-factor authentication codes the same day. Catching a problem on day one beats discovering it at the airport.

Common mistakes to avoid

The most expensive mistake is cancelling the old contract before the PAC transfer finishes. Cancelling first kills the number you were trying to keep, so always transfer first and let the old contract end itself through the switch. Another common one is switching while still in a handset contract without budgeting for the termination fee; sometimes paying it off is still worth it against the savings, but do the arithmetic first. Finally, if you use a second number for work or a smartwatch plan, check whether those move with your main contract or need separate handling.

Frequently Asked Questions

Is switching mobile provider in the UK free?

The switching process itself is free under Ofcom's text-to-switch rules. You only pay if you are still within a minimum contract term, in which case early termination fees may apply. Texting PAC to 65075 costs nothing.

How long does it take to keep my number when switching?

The number usually transfers on the next working day after you give your PAC code to the new provider. The code itself is valid for 30 days, so you can collect it whenever you are ready.

What happens to my old contract when I switch?

You do not need to cancel it yourself. The transfer completes the switch and ends your old service. Your old provider will send a final bill, which you should check and pay promptly, especially if any termination charges were owed.