Does the upgrade rule apply to the line with the upgrade or the line the phone is activated on...or both? For example, I have 3 smartphones with unlimited data and 2 regular phones with no data. I know if I upgrade a line with the unlimited data I will lose the plan but if I were to use the upgrade from one of the regular lines but activate the new phone on a line with the unlimited data would I still lose the plan? Thanks for the help!
I could have sworn this was answered already. Anyways no you don't lose the plan. You only lose the plan if you take a discount upgrade on the line with unlimited data and extend the contract. Since you are getting the upgrade discount on an another line then of course you won't lose the plan. It's no different than if you bought a phone off ebay.
Now all that being said the regular phone you just used the upgrade on won't be eligible for another upgrade for 20 more months. You can't move your upgrade to their line when it comes up otherwise you will lose your unlimited. So the person with the regular phone better like the phone they got. Or I guess you could give them your old phone.