So, I have just the SIM card for one of our iPhone numbers, but no phone. If I buy any iPhone should I be able to just slip that SIM card into the phone and have everything good to go? Or will I need to jump through some special AT&T hoops before? Long story short, lost phone, wasn't eligible for upgrade yet so we opted to add a "ghost" line so we could get the cheap price on the replacement iphone. They put a SIM card for the number we were replacing the phone with into the new phone and just gave us the SIM card for the ghost number. Lost that phone too (don't ask) and am trying to figure out the cheapest way to replace the phone. I figured if I could use the SIM card from the ghost line then I could buy any iphone online and it should work? Thanks guys!