SIM Card Switching
i have my sisters old phone but its on U.S Celluar and my phone is on AT&T, can i switch the sim cards?
Question marked as
Maybe. If it is locked to US Cellular, it will have to be unlocked. Have your sister go to their website and see what the requirements are to unlock it. If it can't be unlocked, then you won't be able to use it on AT&T.
The easiest way to find out is to just go ahead and put the sim card in the phone and see if it will connect to AT&T network. If you get a message along the lines of the "sim card is not recognized" or something like that, then it is locked.