[eggpy]

From the Project Fi FAQs:

>Project Fi is available on the Pixel, Nexus 6P, Nexus 5X, and Nexus 6. Currently these are the only smartphones to support our network of networks. You must have the North American model of the above devices in order to use it on the Project Fi network.

[coolsunglasses]

That's for official support. Project Fi worked fine on my iPhone SE.

However, I had problems with Project Fi sending my calls to random other peoples' phones across the country even when I was using my sim in my Nexus so I went back to T-Mobile.

[gaahrdner]

I recall it "working" on other phones, but it's stuck on T-Mobile or Sprint (depending on your phone's hardware), and you lose out on some functionality since it uses specific bands[0]. Plus you still need an approved phone to activate it.

0. http://arkienet.com/2016/03/fi-on-a-non-nexus-phone-is-like-...

[bduerst]

AFAIK, Fi uses both T-Mobile and Sprint if you have a dual band phone, and wifi if you're in a building without reception. Most phones have been dual band for a couple years now.

[praneshp]

Hey, this happened to me. The reason was that one of my older phone numbers was available to Google somehow, and it made that number a backup number to Fi. So when I dropped a call, it made a call to that old number, which is now owned by someone else (A nice lady who even helped my wife debug what was going on.).

[coolsunglasses]

Holy crap I thought I was never going to resolve that mystery!

Thank you!