check the step by step guide here ..
You can transfer your old number to giffgaff, it could be switched over as early as tomorrow if you get a wriggle on. Two simple tasks, ask your old network for your “PAC CODE” and let us know what that code is.
If you have your "PAC CODE" already, head to Transfer you number
If you need more information about the method to transfer your phone number to giffgaff, this guide will tell you all about it.
Click the link below for more information on how to sack your old service provider and bring your number to giffgaff.
Every service provider is obliged to give you the PAC code.....!
see this article, it takes you through the whole procces
or if you have your pac code and everything and just want to go to the form see this link:
hope this helps
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