This service is good for out-of-contract and clean IMEIs.
In-contract, blacklisted and unpaid IMEIs will be rejected and refunded.
If your AT&T IMEI is in-contract or blacklisted use the following service instead:
USA AT&T ALL Models Premium LUMIA, KYOCERA, BLACKBERRY, AMAZON, NEC, SONY [No iPhone]
iPhones are NOT supported by this service.