stclair49 wrote:First off, Verizon phones, unlocked or not, will not work on AT&T's network. Different technology.
If you have an unlocked GSM smartphone, then YES, you will have to pay for a data plan on AT&T's postpaid network. It is required, no way around it.
However, an unlocked GSM smartphone can be used on AT&T's prepaid network without a data plan.
Ahh, thanks for that! I was aware of Verizon and AT&T using different technologies, but I was not sure if their phones would work on AT&T's network since as far as I'm aware, their 4G LTE devices do use a SIM card. 
Good learning experience from this I'd say! 
~ Evandela ~
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