Darksurf, Dec 20, 2018 : Just got the 6T McLaren, plugged in my Google Fi SIM. Went looking for an option to enable WiFi calling, can't find it. I've spoke with other people who've had better luck than I and found just disabling cellular data allows them to make WiFi calls, but this isn't working on mine. I checked settings, internet & WiFi, SIM & Network, SIM1 and there is no WiFi Calling option to enable. I do get VoLTE though. how can I enable WiFi calling on this phone? thanks edit: just inserted my brother's TMO SIM and WiFi calling option appeared like magic, switched back, option disappeared. is there supposed to be data on the SIM that enables WiFi calling or does the phone recognize the carrier and enable it? technically Google Fi is just an MVNO with TMO as the default/primary carrier it uses.