Every cellphone's imei number tells the carrier exactly what phone it is. That is what determines whether or not this phone is compatible. T-mobile's system seems to allow more devices to be compatible with their network than at&t or verizon.

The listing says that this phone is unlocked, but won't work with verizon or sprint. This phone is not what it says it is! Not sprint. The camera quality is horrible and it gets stuck in the samsung logo mode for quite a few minutes when rebooting.