How to deactivate one phone and go to another?

[hofnar]

I got a 5, I don't care about skuffs. But the reception on the 5 is terrible in my apartment and I want to switch back to my 4S where I know I can talk. Can I do that myself or do I need to go to AT&T?

 

[LandonDonovan]

I got a 5, I don't care about skuffs. But the reception on the 5 is terrible in my apartment and I want to switch back to my 4S where I know I can talk. Can I do that myself or do I need to go to AT&T?

The 4 uses a micro SIM card, but the 5 has a nano SIM card. You'll need to go back in to get a new SIM card unless you buy a nano to micro adapter on eBay.