hey i have a quick question. if i am going to sell my old iphone, what should i do to it first? i know to remove all my pictures. is there a way to "reformat" before i sell it?
This is what the big gray "Restore" button in iTunes is for. Push it, and 10 minutes later you will have a clean device, exactly the way it came out of the box from a configuration/data perspective.
On the phone go to Settings, General, Reset, Erase All Content and Settings.
From my understanding, when you activate you new phone, the old SIM card becomes deactivated/unusable. However I think I'll take the SIM cards out of my iPhones before selling, just to be safe.
Do people that buy used iPhones have to buy a new SIM card from AT&T?