Unlocking an AT&T iPhone 6s and using on Verizon

[PD081]

Hi all,

My girlfriend and I each have an iPhone 6s on AT&T. We are not happy with the service (mainly issues with receiving group texts). Both of our iPhones were purchased through AT&T. Once these phones are paid off, is it possible for them to be unlocked and then used on Verizon?

Not sure if this helps, but these are the models of the two phones:

iPhone 6S 64GB Space Gray (GSM) AT&T MKQ92LL/A
iPhone 6S 64GB Rose Gold (GSM) AT&T MKQD2LL/A

Any help would be much appreciated.

 

[C DM]

As long as they are unlocked they should work fine on Verizon.