Call VZW when you receive the phone. Main thing is DO NOT turn on the iphone5 or it will begin activation under your mom's number and that could cause delay of up to 24 hours to activate your i5. If you are the account ownes or one who can make changes you can do this yourself. if not, your mom may have to grant verbal permission when you call VZW. They also will ask for your account password if one is established. Just tell the rep that you received your iphone ordered under another number and want to transfer it to another line. They will ask for your SIM Card #, found on the receipt or box, and maybe some other information. Chances are they can pull that information up in their system as well. Also, do not call from the line/number you want the iphone transferred to. That phone will probably need to be powered off for the transfer to process.
I did the same thing and took a couple hours but activation and switching the phone to another line than the one I ordered it under was fairly simple.
