Watch phones come with two types. GSM Tri-band 900/1800/1900Mhz Watch phones can be used worldwide including USA, Canada, UK, Europe, Australia, Mexico etc. GSM Dual-band 900/1800Mhz Watch phones can be used in UK, Europe, Australia, Asia but NOT in USA, Canada and Mexico.

GSM Tri-band Watch phones can be used with AT&T, Cingular, Tmobile, and other GSM carriers in US. Some areas in US may not be covered by the 1900Mhz signal and then cannot use the Triband watch phone. Call your carrier to verify before you buy.