I would love to know the answer to this, too. I have every intention of getting the Surface Duo and I would hate to have to change providers.
I believe I saw official support was only AT&T, Verizon, and T-Mobile. Also depending where you buy it it might be locked to AT&T only.
I am curious if anyone has purchased the surface duo and running it on Xfinity mobile network. If so can you please provide some insight as to you experience. I assume that you purchased an unlocked device from Microsoft and used your existing sim card. Are you having any issues with the duo running on the Xfinity network? Also, what is your comments regarding the duo device, is it worth the cost?
I decided against buying the Duo at this time. I played with one at Best Buy and was less than impressed with the performance of the Microsoft tweeked Android OS on the device. After 30-45 minutes of exploring the default software load, I think it needs to cook a little more as it seems underdone. I read some reviews after my tests and they agree with me. The consensus is that it is a very promising device, but it still needs some work to reach it's potential. Hopefully, when version 2 comes out, Xfinity Mobile will fully support it.
Sorry to inform you but it does not work. I have one. You can make calls and use it on wifi however you can not receive any messages. I'm So upset because it's actually a great phone.