[nr2d]

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.

[spinecho]

I was able to just remove my old sim from iPhone 4 and install into my 4s and it worked just fine.

[Alli]

Part of it depends on the carrier. I recently upgraded from the 4 to 4S and it came with a new SIM. Activating the new phone activated the new sim.

[BreakingKayfabe]

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.

[Cleveland]

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