If my girlfriend is away and her phone is turned off and all I have is her phone number and name can i pay her bill 

Another way to do it is have your kids authorize you as a person to 'make changes on the account'. This way you can supply the number and say you are authorized.

You can make a payment over the phone with a valid credit card on behalf of your friend as long as you can provide the customer's first and last name and the mobile phone number.

If you found my answer helpful, please click on the HELPFUL button so other people can find the answer easier. Thanks!