How do I keep my mobile number when I switch network?

Ofcom's text-to-switch rules removed the retention call entirely. You never have to speak to the network you are leaving, and they are not allowed to hold the code back.

Step by step

1. Decide whether you are keeping the number.Text PAC to 65075 to switch and keep your number. Text STAC to 75075 to leave without keeping it. Text INFO to 85075 first if you want to know what you owe and when your contract ends before deciding.
2. Send the text from the phone that has the number.It is free. The reply arrives within a minute and contains the code, any early termination charge, and any outstanding handset balance.
3. Read what the reply says you owe.Leaving mid-contract can carry an early termination charge, and a handset paid monthly may have a balance to settle. Neither prevents the switch, but both become payable.
4. Note the expiry.The code is valid for thirty days. If it lapses, request another one — there is no penalty, but the old code will not work.
5. Give the code to the new network during sign-up.There is a field for it in every online order, or you can give it on the phone. Check the number you are transferring is typed correctly, digit by digit.
6. Do not cancel your old contract yourself.Using the switching code cancels it automatically on the day of transfer. Cancelling separately can lose the number permanently.
7. Keep the old SIM in until the switch happens.The transfer usually completes on the next working day. Until it does, calls still come to the old SIM, and there is often a short window where service drops while it moves.
8. Check your two-factor codes after the switch.Anything that texts you a code will now arrive on the new SIM, which is fine — but confirm you can still receive them, particularly for banking, before you throw the old SIM away.

Tips

• Switching is a good moment to move from SMS codes to an authenticator app, which is not tied to a SIM at all.
• If you use an eSIM, the process is identical but the new network sends a QR code or activation link rather than a physical SIM.
• Business and pay-as-you-go numbers use the same process, though a very old pay-as-you-go SIM may need registering first.

Common mistakes

• Cancelling the old contract before switching — The number is released when the contract ends, and once released it cannot be recovered. Always let the switching code do the cancelling.
• Switching in the middle of a house move or a holiday — There is usually a short outage while the number transfers, and delivery of a new SIM adds days. Do it in a quiet week.

If it doesn't work

Questions people ask