Here are some ways to check your BSNL prepaid balance:

USSD code: Dial *123# or *112# on your phone’s calling app

SMS: Text “BAL” to 121
BSNL Selfcare app: Download the app from the Google Play Store or Apple App Store, log in with an OTP, and check your balance

You can also check your last BSNL bill details by sending an SMS to 53334 from a BSNL mobile or to 9478053334 from any other mobile. The SMS should be formatted as “BILL “.

To check your account details, you can dial 1503 or download the MyBSNL app.