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T-Mob 640 with WM10- WiFi Calling?

Eric J F

New member
Feb 12, 2013
Has anyone installed Windows Mobile 10 on their T-Mobile 640 and tried WiFi Calling? If it works, I may go with the Insider's Build; if not, I may keep the phones on 8.1 when it's officially available.

It may have been mentioned somewhere in these forums, but I couldn't find it.


Ambassador Team Leader
Nov 4, 2013
I had installed one of the older buggier builds on the 640 before I gave it to the wife.
Both Wi-Fi calling and VoLTE worked.