If you've never used your new BT Mobile SIM before, the first thing to check is that your phone is unlocked, otherwise your BT Mobile SIM won't work. Find out more about unlocking >
For a quick explanation of what's going to happen, check out our video.
On the day
First, we'll text you to confirm the move's going ahead. It's going to take a few hours - right up to midnight in some cases - so please be patient.
Until your number moves, you'll have two working SIMs: your old one with the number that'll be moving, and the BT Mobile SIM with a new BT number.
Keep your old SIM in your phone for now. You might get a bit of disruption through the day, but this just means the move is happening. It's when your old SIM doesn't work at all that the move is complete. (You'll also know because we'll text you. We'll also text you by 6pm if there's any delay to your move.)
Now pop your BT Mobile SIM into your phone. Your number should have moved across and everything should work when you switch your phone back on. If it doesn't, you might have to wait for a couple of hours while the networks catch up. If you get any problems with calls at this point, it's usually sorted by turning your phone off then back on again.
What if I've already started using my BT Mobile SIM before my moving day?
That's fine. It'll have your new BT number on it until we move your old one across. We'll text you when it's done.
You've said my number's moved, but I'm still having problems
Try turning your phone off then back on again. That often sorts things.
If that doesn't work, contact us >
If you end up calling us, you'll need to have the BT Mobile number we sent with your BT SIM welcome pack.