My moms phone plan is eligible for a few upgrades at a subsidized price. She was gonna buy me a new phone but I'm thinking of getting off her plan and using t-mobile flexpay on my own. Can she go in to the t-mobile store and upgrade the phone, get me the phone but not activate it, and i can then just take it and activate it with flexpay? Or will they force her to activate it on the spot? The carrier again is T-mobile in the U.S.A.