How do I know if my phone has been blacklisted?
If you’ve recently bought the phone second-hand from somewhere other than giffgaff, the only definitive way to check if your particular device is blacklisted is by visiting Checkmend. There, for a small fee (£1.99), you can enter the IMEI number of the device (you can obtain your IMEI number by simply dialing *#06# from your device) and receive a report that will tell you if the phone is blacklisted or not. The Checkmend service is independent of giffgaff. We don’t receive any share of the fees paid to Checkmend.
If you’ve used the phone on giffgaff before you may have reported it lost. Check out the article on lifting the bar if you’ve found a phone you’ve reported lost.