On the day of transfer, it's normal to experience a loss of service until your transfer is fully completed.
You may not be able to use either your old number or your current giffgaff number for several hours and should refer back to this article the morning after your transfer if you're still experiencing an issue. To help, regularly turn your phone ON and OFF throughout the day.
If the transfer hasn't happened as you expect, here are a few steps you can follow that will give you a better understanding where the problem lies and hopefully will allow you to fix it yourself without needing to contact an agent.
There are 3 common situations that we will take a close look at. Click on My profile & settings and have a look at the number displayed under your member name and follow the link to the section that applies to you:
If the number you would like to use is not showing on your account then that usually means that the number transfer is most likely in progress - don't fret, wait till 9PM on the day of your transfer and if you're still having problems contact one of our agents.
Sorry to hear you're having problems getting signal. Hopefully, the information below will get you fixed quickly. The last step is for the situation in which none of the previous ones has fixed the issue:
Make sure the phone is not locked to a different network. You can find out if it is here, and then the Unlockapedia will help you if it is locked.
Switch OFF your phone, remove the SIM and reinsert it. Now switch the phone back ON.