Using an AT&T sim card in a Verizon iPhone 4S

[Hummer]

To make a long story short, I have two iPhone 4S. One is with Verizon on an unlimited data plan and the other is on AT&T with a 2 gb data plan. My Verizon iPhone is a 64GB model. I tried putting my AT&T sim card into my Verizon phone and it worked, but I got an error from iOS that said my sim card was not valid, but I was receiving full bars from AT&T instead of Verizon.

AT&T has much faster data speeds, and instead of having two phones, I'd like to switch out sims when needed and return my AT&T phone. Is this possible?

 

[miles01110]

No.

 

[b24pgg]

I'm not 100% sure on this since there are a ton of unlocking questions that haven't been answered yet, but as far as I know, if you have a Verizon iPhone 4S, AT&T and T-Mobile SIM cards will not work even if the phone is unlocked. The only way you'd be able to use those networks is by using a non-AT&T/T-Mobile SIM and then roaming on those networks.