Switching used to mean phoning your old network and sitting through a retention pitch. Since Ofcom introduced text-to-switch, it takes one text and the old network is not allowed to make you speak to anyone.
Keeping your number: the PAC
Text PAC to 65075 from the phone you are switching. Within a minute you get a code, valid for 30 days, plus a statement of anything you still owe — an early-termination charge if you are inside a minimum term, or nothing if you are not. Give the code to your new network (there is a box for it during sign-up, or you can add it afterwards) and the number moves, usually by the end of the next working day.
Not keeping your number: the STAC
If you want a fresh number, text STAC to 75075. It works the same way and, crucially, closes your old account when the new network uses it. Without a PAC or STAC, your old contract simply carries on and you will be paying two bills.
Just want to know what leaving would cost? Text INFO to 85075 and nothing happens except the reply.
The order that avoids problems
- Buy the new deal first. Your new SIM needs to be active and in your hand before the number moves. Get it working with its temporary number.
- Then request the PAC from your old network, and give it to the new one. Requesting the PAC does nothing on its own; the switch only starts when the new network uses it.
- On switch day, keep both SIMs handy. The old one stops, the new one picks up your number, and any texts in transit can take a few hours to arrive.
- Afterwards, check the old account is closed and any final bill is settled. If you paid by direct debit, do not cancel it until the final bill has gone through.
Things that catch people out
- Locked phones. Handsets sold in the UK since December 2021 must be unlocked. Older ones may need a free unlock from the old network before the new SIM will work.
- Two-factor codes. Banks and other services text your number. Do the switch on a day you are not expecting to need them, and make sure the number has moved before you cancel anything.
- Switching within the same host network. Moving from, say, O2 to Giffgaff still needs a PAC — they are different providers even though the masts are the same.
Ready to move? Compare SIM-only plans if you are keeping your handset, or contract deals if you want a new one bundled in.