USSD Codes to Check Balance in BSNL BSNL USSD Code to Check Balance& Validity *123*1# BSNL data or Internet main balance (BSNL Balance Check) *124# USSD code for GPRS/3G data (BSNL Balance Check) *112# USSD code for 2G data balance inquiry (BSNL Balance Check) SMS “DATA 2G” to 53733