We've built a compatibility checker page to learn whether or not either model of the Light Phone II will work with carriers in your region.
For U.S. Customers:
It will work with the following carriers:
Light, AT&T, T-Mobile, Verizon (no prepaid, no numbershare), Ting, Mint, US Mobile
Unfortunately, it is not compatible with the following carriers:
Sprint, Google Fi, Cricket, Spectrum, Red Pocket, Xfinity, Black, H2O, Consumer Cellular, US Cellular, Metro PCS. There are many carrier partners (MVNO's) that are not supported. We cannot supply a complete list.
What about 5g SIM cards?
The Light Phone II is a 4G LTE cell phone, though 5G SIM cards are backwards compatible with 4G cell phones as well. The 4G network as there a billion 4GLTE cell phones
What about APN Settings?
There isn't currently a way to reset or change the APN settings from the LightOS, you will need to have the carrier make those changes on their end. We do plan to make this possible in future software updates.