How do I know if my phone is locked to another network?
You might get a message like "SIM card not valid", "SIM lock" or "Insert correct SIM card" when you pop in your giffgaff SIM.
If your phone has the logo of a mobile network printed on the outside or on the home screen then it could be locked to that network. But it’s worth checking with your giffgaff SIM anyway as the presence of a logo doesn't always mean the phone is locked.
If you’re stuck, ask our friendly community helpers. They’ll give you some great pointers.