Why Was UPI Down for a Few Hours Over the Weekend? NPCI’s Report Reveals the Real Reason

The Unified Payments Interface (UPI) — India's most widely used digital payment platform — encountered a major service disruption on April 12, 2025, leading to transaction failures and user complaints nationwide.

According to a Root Cause Analysis (RCA) shared by the National Payments Corporation of India (NPCI) with UPI ecosystem partners, the issue stemmed from an overwhelming surge of "Check Transaction" API requests.

NPCI’s Root Cause Analysis Explained

Overload of Transaction Success Requests

A news agency obtained exclusive access to the NPCI report, which stated:

“The issue was identified to be caused by the flooding of 'Check transaction' API. Further, it was observed that a few PSP Banks were also sending requests for 'Check transactions' even for older transactions multiple times.”

This means that the excessive requests from merchants and PSP (Payment Service Provider) banks overwhelmed the UPI servers, which couldn’t process the load efficiently — leading to temporary platform downtime.

How the Issue Escalated

When PSP banks do not receive timely confirmation from the beneficiary’s bank, they trigger "Check Transaction" API calls. Normally, this mechanism ensures the correct status of the payment. However, in this instance:

“The PSP banks also did not wait for the response from UPI system and were repeatedly flooding the UPI system with 'Check transaction' requests leading to further congestion in the system, and prolonged downtime for the platform.”

As per NPCI’s operational guidelines, the “Check Transaction” API is supposed to be called only once every 90 seconds, but this protocol was breached multiple times.

Timeline of the UPI Disruption

Drop in Success Rates

NPCI recorded a reduction in Unified Payments Interface (UPI) success rates during the affected period. As the report mentions:

"NPCI observed a reduction in UPI success rates on 12th April 2025. The success rate degraded to around 50% for about 2 hours and to around 80% for the next 3 hours between 11.40 am to 4.40 pm, it added. The success rate returned to normal at 4.40 pm on 12th April 2025, it noted."

Emergency Measures Implemented

In response to the growing flood of API requests:

“The RCA report said that NPCI advised the PSP bank to immediately stop the ‘Check Transaction’ feature at 4 pm. It also deployed a temporary solution at 4:15 pm to mitigate the cross-site flooding and processing of ‘Check Transaction’ APIs.”

Experts Raise Concerns

While NPCI’s report outlines the mechanics behind the system failure, some industry experts argue that it falls short of identifying the root origin of the issue. As noted by a senior banker:

“The report does not say how this started. Banks check transactions when a lot of transactions fail in the system. It does not specify the origin of the problem.”

NPCI’s Plan to Prevent Future Outages

To ensure smoother performance moving forward, NPCI has laid out the following steps:

Reiteration of API Protocols

“It will be reiterated to the PSP Banks, the NPCI guidelines regarding the use of 'Check Transaction Request' APIs. The raw data files are available to PSP Banks and Acquiring Banks with the final status of the transactions (source of truth) every 2 hours. Banks and their partners are advised to use these for confirming transaction status instead of flooding the system.”

Monitoring for Anomalies

NPCI has assured that they are closely monitoring the platform for any further abnormalities that could affect service stability.

Recent UPI Outage Trends: Not a One-Off Event

This isn’t the first hiccup in recent times. UPI experienced four service disruptions over the past three weeks, affecting millions of users and raising concerns over the robustness of India’s digital payment infrastructure.

As UPI usage continues to grow — processing billions of transactions monthly — system stability is paramount to maintain public trust and avoid cascading failures across banks, merchants, and digital platforms.