How do u unlock an at&t phone?
Hi is your phone locked to AT&T network or else whether your AT&T phone is locked .If your phone is locked to AT&T network .Then visit ClassicUnlocking.com here they ask you the mobile model and the IMEI number of your mobile .Then at last they deliver you network unlock code to unlock your phone .After unlocking your phone you can freely use it with any GSM sim ..
All SIM unlock codes are tied to the particular device IMEI and are carrier specific. The request for that code would need to be made from the carrier that the phone was originally manufactured for (in your case contact AT&T at 1-800-331-0500). Each carrier has their own guidelines as far as what requirements have to be met before that code will be given out. This is a free process.