Hi. You can change your number yourself on gg website
* Log in here: https://giffgaff.com/profile/details#msisdn
* Go through and understand the instructions and warnings before you go further.
* Click 'Change my number'
* On the next page confirm that you wish to go ahead. This is permanent, you cannot get your old number back after you've confirmed you wish to go ahead. Your number will be changed within 4 hours.
Please not that this service is only available between 4.30am and 9.30pm, and can only applied once per account.
You can also can ask an agent
Contact an agent using the link belowhttps://giffgaff.com/support/ask/call_barring
They will respond within 24hrs.
Check for reply from agents using link belowhttps://giffgaff.com/support/questions
For further details on how to change your number, please click on the link belowhttp://community.giffgaff.com/t5/Solve-your-questions/Can-I-change-my-Mobile-Number/ta-p/3488137