Here are some ways to check your Vi (Vodafone Idea) prepaid balance:

USSD code: Dial 199# from your Vi phone and select the option to check your recharge balance. You can also dial 19921# to see your primary balance, validity, and other balance details.

Vi app: Download the Vi app, log in, and your balance will be on the home screen.

WhatsApp: Chat with the Vi assistant Vic on WhatsApp 24/7, or chat with a Vi executive at 9654297000.

Online: Visit the official Vodafone website and sign in with your mobile number.

IVRS: Call 199 to check your balance.

You can also use the *199# code to see a list of options for your account, including balance and usage, my offers, manage account, and more.