quoted from Google:
You’ll have calls, texts, and data on T-Mobile’s network as well as international roaming. You won’t be able to make calls or text over Wi-Fi, use visual voicemail, or use data hotspots outside the US.Texting will work with some additional setup, but iMessage works right away.
- iPhone XS
- iPhone XS Max
- iPhone XR
- iPhone X
- iPhone 8 & 8 Plus
- iPhone 7 & 7 Plus
- iPhone 6S & 6S Plus
- iPhone 6 & 6 Plus
- iPhone 5S
- iPhone SE
All phones must run iOS 12 or higher.
However, iPhones and other compatible phones can actually make wifi calls through non FI apps like Hangouts etc
