The National Payments Corporation of India (NPCI) has directed banks to limit the use of the ‘Check Transaction’ application programming interface (API) following a major outage in the Unified Payments Interface (UPI) on April 12.
The outage, which lasted over five hours, was caused by a surge in transaction status queries sent by banks. The spike in API calls overwhelmed the system, leading to a sharp drop in transaction success rate.
During the disruption, which lasted from 11:40 am to 4:40 pm, UPI transaction success rates reportedly fell to around 50%, affecting millions of users across the country.
To prevent similar issues, NPCI has instructed banks to delay their first ‘Check Transaction’ API call until at least 90 seconds after the transaction is initiated or authenticated. Additional status checks may be made only after intervals of 45 to 60 seconds, with a maximum of three checks allowed within two hours of the original transaction.
Payment service provider (PSP) banks have also been asked to moderate all API traffic to avoid unnecessary repeat calls for the same transaction. NPCI said banks must also undergo system audits by CERT-In empanelled auditors to assess API usage and system behavior, with annual reviews to follow.
UPI, India’s real-time payments system developed by NPCI, has become the dominant mode of digital payments in the country, processing over 10 billion transactions per month.
