Good question. I cut my 3GS card down already to fit the iPhone 4 and almost dicked it up in the process. Not sure if they can be cut down further or if you'll get a new one with the new phone (probably).I have a iphone 4S . I want to get iphone5 and give my 4S to my wife. I hear that sim card in iphone 5 will be much smaller than 4S. So how do I use my 4s sim card in iphone5 and sim card from iphone 5 in 4S?