I have sprint with 3 lines. One line i just upped in November and bought a iPhone 7. The other two contracted lines are up in a few months. I am wanting to switch to T-Mobile however they require you to turn in a phone in order for them to pay the ETF. I was wondering if I could switch my iPhone 7 to a another number on my account (that has a contract that is almost over) and trade in an older phone without any issue from Sprint. This way I can use the iPhone 7 with T-mobile.
I guess what Im asking, is the 2 year contract is tied to the number (service) and not the phone?