T-mobile can deny jump upgrade if you trip knox flag, but I bet they won't..
Here's why..the new jump rule requires you to have paid at least half of the price of the original phone.
The phone that you trade in is gonna be in good working condition and probably not very old. A phone like this is usually gonna be worth more than 1/2 the original full price.
T-mobile jump is a rip off in my opinion
I had jump on my S4. I planned on using it to upgrade to S5 when it was released.
T-mobile changed the jump policy, and now jump wasn't worth using.
Here's how I jump....
When GS5 was first released i got it right away from t-mobile by adding another financed equipment plan.
I then payed off the remaining balance on the S4 ($300), unlocked it, and sold on it Ebay($400).
I got a brand new just released GS5, $100, and my T-mobile monthly bill stays the same.
**Actually it's $2 dollars less after removing jump. ($8 for handset protect without jump)**
Sent from my SM-G900T using XDA Premium 4 mobile app