AT&T tried to screw us over today. My kid bought a refurb iPhone 5c from groupon and we wanted to move his pay-as-you-go SIM card to the new phone but it's a different size SIM card (full size to nano). We had this same issue when getting my wife a new phone - different SIM card size. But that worked fine. So this guy was telling my wife and my kid that smartphones can't use pay-as-you-go service. Which is bullshit. And iPhones can use it too because I moved my wifes old dumb phone to my old iPhone 3GS years back. It worked without a hitch. AND here I am looking at an AT&T support page that says it works. You don't get data service with pre-paid pay-as-you-go (at least on AT&T), but it works for everything else. I had to talk to the guy on the phone and tell him to just transfer the sim card. Well even then he said he'd look into it and finally he says yes it does work and he's going to do it. Got to love AT&T.