I am switching from htc 8 to htc 10 with att. the 10 is a verizon.. what do i need to do?

[AC Question]

Simply take out the sim and place it in the new phone?

 

[dansouza]

An AT&T sim will not work in a Verizon phone without it being unlocked and reprogrammed for AT&T. Verizon uses CDMA whereas AT&T uses GSM. You may be able to take it somewhere and have it unlocked. You need to go to AT&T's website and check the IMEI to see if the phone is compatible.

https://m.att.com/shopmobile/wireless/byop/checkIMEI.html