Need help to find the best way to handle this: I have an iPhone5 under a 2 year contract with ATT. I still have to unlimited data plan so don't want to mess with that. I got an iPhone5S (T-Mobile unlocked) and wanted to get the iPhone5 unlocked so I could give it to my mother who lives abroad and need an unlocked phone and I would use my ATT sim card on the 5S and keep my contract and plan as it is. This morning I went to an ATT store and asked if I could pay the remaining balance on the subsidized iPhone5 so I could own it and do it all legally and by the book. They said there is no way for me to do that and I have to keep the iPhone5 until the contract ends to get it unlocked. I know there are was to unlock the phone on the web but I wanted to do it the right way but apparently there is no way to do it. Question: if I unlock the iPhone5 on the web ad give it to my mother and plug the ATT sim card on my new 5S will it work? Will I have any problems with my ATT account/plan/contract? Tks for your help.