https://www.cnet.com/news/free-iphone-xr-on-t-mobile-when-you-trade-in-an-old-iphone/ > But obviously a deal that sounds this good has some fine print. So here's what you need to know. > First, you don't get the phone for free. Instead you are compensated for $750 over the course of 36 months. That comes out to around $20.84 a month, each month from now until March 2022 or thereabouts.