I am upgrading to an iPhone 4S will I be able to use my old SIM card from iPhone 3gs
I am upgrading to an iPhone 4S will I be able to use my old SIM card from iPhone 3gs as I understand that the 4s uses a micro sim Thanks
iPhone 4S, iOS 7
Not without attempting to cut down the SIM. The iPhone 3GS uses a full size SIM. I'd strongly suggest just getting a new micro-SIM from your cell carrier.
Regards.