I currently have a Verizon Wireless account for my wife and myself.
My mother had her phone stolen and there are 6 months left on her phone payoff plan on Sprint (I told them not to go to Sprint).
She's in a family plan on Sprint with 2 other family members, 6 months left for everyone.
I'm wondering if the iPhone 7+ or 8+ purchased from the Apple store Unlocked and SIM-free would work on both the Sprint network for 6 more months then work on the Verizon network for the rest of eternity when they rejoin the fold.
Can anyone help?
A secondary question is if all 3 family members join my plan, would they still receive a trade-in promotion for their Sprint phones (except for my mom, of course)? I may need to post this question in another area, forgive me if I am breaking rules here.