Fi on a non-Google phone is like mowing your lawn with a weed eater….

Project Fi LogoI’ve seen the “can you use Project Fi with an XYZ model phone” question over and over. Invariably someone (or several someones) will reply “yeah, it works”. And while this answer is kind of / sort of technically correct (with caveats), it’s misleading!  When I see this I imagine  quotes around the word works… it “works” – unfortunately, a lot of people take it at face value.


Before we go any further, you need to understand a couple of basic issues.  GSM carriers (like T-Mobile and AT&T) use sims to provision service on their network. The sim’s unique id is what is activated by the carrier and ties the service to whatever phone it’s inserted in. On the other hand, CDMA carriers (Sprint) only use the sim to provision the data portion of their service (LTE) – the cell side is provisioned based on a unique id in the PHONE.

You also need to be aware that not all phones have all of the US cell bands that are used by T-Mobile and Sprint. For instance, the International versions of Nexus phones don’t have any CDMA bands.

Activating your Project Fi Sim

The first thing that happens when you start the Project Fi activation process is that the Project Fi app verifies that you are using a supported phone. If you aren’t on a supported phone, the app stops the activation process. In short, you can NOT activate a Project Fi sim on an unsupported phone ( to me this means it does NOT work).

If you are on a supported phone, the app activates service on T-Mobile using the sim’s ID and then activates the PHONE’s unique ID on the Sprint Network.

So, I’ll just activate my sim in my friend’s Google Phone

And now we head down the rabbit hole.  Yes, you MAY be able to do that – BUT, you will be activating your friend’s phone on Sprint. This has a couple of possible side effects:

  • Your friends phone may have issues if he tries to activate Sprint service (either Sprint, Project Fi or any Sprint MVNO).
  • When you change out the sim, your phone will not be able to utilize the Sprint network. It will basically be a T-Mobile ONLY sim.

OK, so I’ll use a “Data Only Sim” Instead

Not so quick. The “Data Only Sim” is an ADD ON to a full sim, so if you can’t activate your primary sim, you won’t be able to use the data only one. This sim is intended as a way to get access to a SECOND device (like a tablet), not as your primary service.

Additional Things To Consider

  • Google will NOT support Project Fi on an unsupported phone.
  • Google has stated in the Network Policies section of their TOS that all “supported devices” will be listed on the Project Fi website and that they “reserve the right to suspend any device that we reasonably determine is unsupported”.  So, yes, they have the option of terminating your service for using a non-approved phone.


Basically, it’s like asking a group of guys “can I mow my lawn with a weed eater”?  There will be at least one guy that will says “sure, you can do that”. And while he is technically correct, and may be doing it himself; it is only kind of “working”.

Regardless of what you’ve heard – No, Project Fi sims do not work (note the lack of quotes) on unsupported phones! You probably need to consider a T-Mobile plan (or one of it’s MVNO’s – like Straight Talk).

Have fun and enjoy Project Fi!



5 thoughts on “Fi on a non-Google phone is like mowing your lawn with a weed eater….”

  1. Not really, If you’ve done the math and looked at the map coverages to see that you rarely are a data hog or go into the boondocks of no service, using project fi (t-mobile only) on a unlocked non nexus phone is still as good as using it on a nexus phone.

    1. You’re right it “works”, it just doesn’t work with Sprint or US Cellular – it’s basically T-Mobile only. And you’ve probably locked the 5x off of Fi and Sprint.

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