Hi everybody I'm trying to see if I can get an iphone 5 and switch it to another line on my account. I have 3 lines and one upgrade available. I asked an att rep this mornign via a chat and he said that an upgrade can only be used on the line that is being upgraded. I'm currently using a 3GS and am aware there is a different sim card in the 5. My question is does anyone know how I could switch the upgrade or get a new sim or any other way of putting the phone on a different line. Thanks in advance.