I decided to upgrade from my iPHONE 4 to a 4S. Can I just remove the SIM from 4 and install it in my new 4S in order to activate it? I did this when I upgraded from my iPAD (1) to my iPAD 2 with no problems.
I did the same. But just to be sure I called AT&T and had them activate the sim card that came with the 4S. Since the 4S is hspa+ compatible, I wanted to be sure that I started using it with the designated sim card that came with it.
Mine came with a sim too as as you'll see activating it on ios 5 without the need for a computer it'll have the # programmed into the initial activation