Long story short, my wife is ATT upgrade. She's always wanted a cell phone as basic as it gets, but is now thinking she might like an iphone, not sure. If we bought her the new phone when it came out, would we be able to swap SIM cards and reactivate my number with her phone and her utilize my current one. Being new to the iPhone, she doesn't care about the new hardware features and knows mine is in mint condition. I know you can utilize another iPhone with a sim, as my first one was inherited when my father passed. We just called ATT, popped in my old sim and it was reactivated. But I didn't know if there were any hardware swapping rules within the same account. We'd still be under contract, so the money/subsidy part would seem the same to ATT.