UPDATE: As of the 11/29/2019 Google Fi announcement, this article is pretty much old news but I’m leaving it here for reference.
I’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. No other carrier automatically switches between GSM and CDMA, so, this means that Fi has to have low level access to the radios that most carriers don’t need and most manufacturers don’t currently support.
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.
About the Project Fi Sim and Unsupported Phones (I-Phone)
The Project Fi sim is reportedly different than other sims in that it has up to 10 virtual sims on the card. This means that any phone you put it in will probably have to have a firmware update (at least) to utilize any of the virtual sims other than the first one (which is probably T-Mobile as that is how the sim will act when insert it in a non-Fi phone). Unfortunately, this means that the phone manufacturer (eg, Apple) would have to make changes to their phones before it would be able to fully support Project Fi (I honestly don’t see Apple ever doing that).
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!