NPCI Blames Banks for April 12 UPI Outage Check Transaction API Flood Causes System Crash

There was a big outage in the UPI service held on 12 April, which disturbed people across the country for a few hours. Now, the National Payments Corporation of India (NPCI) has shared its investigation report regarding this outage. According to the report, the reason for the outage was to send excess “Check Transaction” request on the UPI system. This heavy load not only took the payment server closer to the crash, but for about 5 hours, crores of people faced problems in payment transactions.

Moneycontrol Report It has been reported that some merchants and PSP Banks (banking partners of UPI apps) sent the system repeatedly check transaction requests, while permission to do so is only once every 90 seconds. Instead, some banks started verifying even old transactions, which slowed down the entire network and the transaction success rate suddenly fell to 50%.

It has been further reported that NPCI noted a drastic drop in transaction success rate on UPI from 11:40 am to 4:40 pm during this outage of April 12. The success rate was just 50% in the first two hours, while it remained close to 80% for three hours. Eventually at 4:40 pm, the system became normal again.

During this incident, many PSP banks continued to send requests to the UPI system with “Check Transaction” API. Whereas NPCI rules reportedly say that this call should be only once within 90 seconds. This frequent action taken created a jam-like situation in the entire network. As a result, neither the user got the reply to the payment, nor the banks were able to clear the transaction on time.

NPCI, taking immediate action on this, asked PSP banks to stop check transaction calls at 4 pm and also put a temporary solution in the system at 4:15 pm to stop the flood of cross-site requests. Also, all PSPs and Acquering banks have been advised to use the raw data files being sent every 2 hours for the final status of transactions, not to increase the load by calling the system repeatedly.

However, it was not told in the report why these transactions were failing and why were so many failures in the beginning. A bank official told the publication that the real reason has not been given in the report, which should have been the most important part.