Question about Lumia 640 and different carriers

[klargh]

With WalMart selling multiple carrier Lumia 640s, are there drastic difference between the different carrier branded 640s (bands and other things)? With the native Wi-Fi calling headlined as an update for the 640, would I be able to get an ATT GoPhone 640, unlock it, then use the Wi-Fi calling on T-Mobile?

 

[libra89]

With WalMart selling multiple carrier Lumia 640s, are there drastic difference between the different carrier branded 640s (bands and other things)? With the native Wi-Fi calling headlined as an update for the 640, would I be able to get an ATT GoPhone 640, unlock it, then use the Wi-Fi calling on T-Mobile?

Nope, WiFi calling is built into the T-mobile variant. The bands in some ways are different.

 

[miguel11691]

The differences are the bands in all the variants and TMobile is the only one with Wifi Calling included in their device

 

[jwpear]

Is there any chance an unlocked AT&T 640 variant would work on Verizon? The bands seem similar, but I'm not sure what governs how well cell phones work on different carrier networks. Most of the VZW bands are there when I compare the specs between the Icon and 640. I'm guessing there is some carrier firmware required also.

I recently unlocked a Lumia 520 that was an AT&T GoPhone. I like that I do have a little freedom to move it around, at least between AT&T, T-Mo, and the small VNMOs. I'm considering moving to one of those carriers if VZW doesn't get the 950 in the fall. I like VZW's network, but want to stick with my phones of choice.

 

[pankaj981]

Verizon is CDMA, the 640 is GSM, it won't work.