We've built a compatibility checker page to show which carriers each model of Light Phone will work with in each region. There are three versions of the Light Phone:
Light III - Works in all regions listed in the compatibility checker
Light II (North American) - Works in the US and Canada only with compatible carriers
Light II (International) - Works outside of North America in regions with a compatible carrier listed
For U.S. Customers:
The Light II and Light III work with:
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 by T-Mobile, Tracfone, Straight Talk, Puretalk
Unfortunately, we're not compatible with most of the carriers that work off of the networks of the major carriers (sometimes called partners, MVNOs, or sub-carriers). There are a number of reasons, mainly related to the main carrier not passing through functions for Light Phone. There are many carrier partners (MVNO's) that are not supported. We cannot supply a complete list.
5G or 4G?
Light III - the Light III is a 5G phone and requires a 5G data plan from a compatible carrier. It is backwards compatible with 4G networks too if 5G is weak or non-existent in your area.
Light II - the Light Phone II is a 4G LTE cell phone, though 5G SIM cards are backwards compatible with 4G cell phones as well.
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.