MUMBAI: Kotak Bank has advised customers to use its mobile banking app or net banking platforms to check account balances after reports of a Delhi-based individual seeing a 37-digit balance through a third-party UPI app emerged.In a statement, the bank said media reports suggesting an unusually large balance were incorrect. It urged customers to verify account details using the bank’s own digital channels. According to reports, the customer accessed the balance through the Navi UPI app, which allows users to view and operate linked bank accounts without logging in to the bank’s platforms. When customers install a third-party UPI app, they link bank accounts by verifying the mobile number registered with the bank and setting a UPI PIN. The app connects with the customer’s bank through Application Programming Interfaces (APIs) provided by National Payments Corporation of India (NPCI). Each account is assigned a Virtual Payment Address, which acts as a proxy for account details.For any transaction or balance inquiry, the UPI app sends the request to NPCI’s central switch, which routes it to the bank. The bank processes the request – debiting the account for payments or providing real-time balance data – and responds back.