Can I use GSM SIM in Verizon phone?

Originally Answered: Can a GSM phone work on Verizon? No. Unless you call the carrier or find a way to unlock the phone from GSM, you cannot use Verizon on the GSM phone .

The best way to know for certain is to compare the specs. The Verizon phone must be GSM compatible and support the same LTE frequency bands that either AT&T or T-Mobile support. T-Mobile provides a tool on its website that allows you to type in the serial number of your device to double check.

In the US, Verizon, US Cellular, and the old Sprint network (now owned by T-Mobile) used CDMA . AT&T and T-Mobile used GSM. Most of the rest of the world used GSM. The global spread of GSM came about because in 1987, Europe mandated the technology by law, and because GSM comes from an industry consortium.