First, I contacted Sprint and they said in chat it could be done in store. Info varies though depending on who you speak to anywhere. Just trying to get confirmation maybe from one who did it. The plan is to give my mother who lives in New York my iPhone 6S plus. I live in Miami so going to the store and doing myself is not an option right now. This is an unlocked T mobile version 6S plus. Was purchased full price from apple so never actually tied to carrier. From what I read there is mixed info, but more that it will work. CS said would just need to go to the store and get a SIM. Just trying to confirm to avoid shipping if it won't work. Some threads say it work. Others it won't. Need specific SIM. Specific device. Etc.. Any info is appreciated.