Official Unlock by AT&T
Recently it became known about the decision of AT&T to independently unlock iPhones purchased from it. And today it happened ... It would seem - "the matter is in the hat", if not for a few "buts."

Firstly, the contract should expire and there should be no obligation for the “telephone”. Secondly, when I tried to unlock my stale “brick”, they demanded my contract number with AT&T (it is indicated in the documents when buying). Therefore, if everything suits you for the above points, then go ahead to the AT&T website to free your devices!
Here is an example of how to contact support AT&T ( www.youtube.com/watch?feature=player_embedded&v=GfUqTrZjxJc ).

Firstly, the contract should expire and there should be no obligation for the “telephone”. Secondly, when I tried to unlock my stale “brick”, they demanded my contract number with AT&T (it is indicated in the documents when buying). Therefore, if everything suits you for the above points, then go ahead to the AT&T website to free your devices!
Here is an example of how to contact support AT&T ( www.youtube.com/watch?feature=player_embedded&v=GfUqTrZjxJc ).