Upgrading from a iPhone 4 to 4S, only need to swap SIM card?

[jazoi]

I recently upgraded to the iPhone 5 from a 4S. My wife has an iPhone 4. I want to give her the iPhone 4S. Do I only need to swap the SIM card from the 4 to the 4S for that? Or do I need to call AT&T?

 

[Applejuiced]

You will have to call AT&T too to give them the IMEI number.
This way they can upgrade the phone data plan on their end so you can get the faster HSPA+ speeds available for the 4S.

 

[jazoi]

You will have to call AT&T too to give them the IMEI number.
This way they can upgrade the phone data plan on their end so you can get the faster HSPA+ speeds available for the 4S.

Thank you! I will do so tomorrow.