Here's my situation. I currently have two cell phones on alternating contract periods, so every year when one line becomes eligible for upgrade, the other still has one year left. One is a work line where I don't pay for service (but I do pay for and own the hardware), and the other is a personal line. Last year, I upgraded one of the lines to an iPhone 4S. I swapped the sim cards on the phones, so that the older line was now using the 4S. That older line's contract ended in July, and as of September I transferred the phone number to VZW. I'd like to sell the 4S, preferably unlocked, but only if it's a permanent one. I know that one of ATT's policies for unlocking iPhones is that they will only unlock a phone if it has completed its associated contract. My question is, when I submit the IMEI number for unlock, will it be associated with the account where it was being used (the expired contract, originally tied to the iPhone 4), or the line that's still in service (has one year left, currently using the iPhone 4). Appreciate the help!