Google Fi will stop activating non-VoLTE phones in January, and encourage customers with older phones to upgrade with a $100 credit provided they purchase a new phone from the Fi store and activate it before December 31st.
Google’s hand is focused on the matter. Customers subscribe to Google Fi, but as an MVNO, Fi actually piggybacks on T-Mobile and US Cellular’s networks to provide coverage. Since T-Mobile has already announced its own plans to phase out support for non-VoLTE phones starting in January 2021, Fi has to as well.
VoLTE stands for “Voice over LTE”, which is the handling of phone calls; over LTE data rather than older 3G tech. VoLTE calls are typically clearer, with fewer drops in connection, though they are completely unavailable to older phones that; only use 3G radios and even some early LTE models as well. Google stopped activating 2G and 3G phones; on August 4th of this year according to the Fi FAQs, but requiring VoLTE all but assures 3G’s days are numbered.
There’ no hard date for the end of 3G service at Fi, but it is coming; and until Google makes an official announcement, your best bet is to look for when T-Mobile; ends its coverage. T-Mobile gained a lot of sway over what Fi can; offer when it purchased Sprint, giving it control over both of the biggest networks Google Fi relied on.
There are actually a couple of cheap options on the Fi store that; could serve as a quick fix. There is Google’s Pixel 4a, which normally sells for $349, but there are also options; that you could get for less than $100 with Google’s current holiday promotion.