Mobile Phone Manuals Reviews of Mobile Phones Need the BSNL Balance Check USSD Codes? If you want to check the balance on your BSNL SIM using the USSD code then you will note below how to do this. There are a number of USSD codes for the BSNL network. You will also find the BSNL customer care number listed below with all the most commonly used USSD codes. Balance check USSD codes are used by all the network providers.