I wanna test if my new iPhone 5 is in fact unlocked now, and the best way to do that is to simply put a different carrier's sim card, such as T-mobile.. The thing is that I need it to be unlocked to use it internationally with foreign carriers, so I don't have any T-mobile plans, and don't plan on having one. They sell really cheap sim cards that I'm thinking about buying it just to find that out, but they come unactivated. Will my iPhone recognize the unactivated sim card and show T-mobile on the top corner, or do I need to like activate it with a cheap plan, or prepaid plan in order for that to work? And remember that I just wanna do that to find if my iphone is unlocked now, i don't have any intentions in use that sim card for other than that!