I hope someone here can give me some advice on unlocking. I'm traveling to Europe soon and would like to use a pre-paid local SIM in my iPhone 5 while I'm there. For that I realized I need to unlock it from AT&T here in the States. I'm not looking to change carrier in the USA though, so my question is will AT&T know or care if I unlock?
I've had an iPhone since day 1, so I'm still on a grandfathered unlimited data plan. T-Mo coverage is poor in my town, so I'm not looking to leave my US AT&T plan, I just don't want to pay their crazy rates to add international voice, text and data for a two week trip!
Can I unlock and still continue to use the same SIM in the USA?