Used Motorola Moto X phones can be purchased online from Amazon. Motorola Moto X phones are compatible with carriers that use the Global System for Mobile carriers.
Used Motorola Moto X phones that are unlocked are compatible with AT&T, T-Mobile and a limited number of prepaid services that use the Global System for Mobile and compatible Subscriber Identity Module cards. They are not compatible with Code Division Multiple Access carriers like Verizon and Sprint. Most of the used Motorola Moto X phones that are available are 16-gigabyte models. Some used phones come with a limited warranty. A 16-gigabyte model can be upgraded to 32 gigabytes or more by purchasing an upgrade device from Motorola.