Check Sony Ericsson mobile or cellphones IMEI (International Mobile Equipment Identity)

On the main screen type *#06#

Information you get from the IMEI (International Mobile Equipment Identity)
    XXXXXX     XX     XXXXXX    X
        TAC      FAC       SNR     SP

TAC = Type approval code of your sony ericsson Mobile
FAC = Final assembly code of your cellphone
SNR = Serial number of your sony ericsson Phone
SP = Spare