The National Payments Corporation of India ( NPCI) has attributed the Unified Payments Interface (UPI) outage on April 12 to a surge in requests from certain banks that were excessively using the “Check Transaction” application programming interface (API), leading to a temporary system slowdown and reduced payment success rates for several hours.
In a note to partner banks and the payments ecosystem, NPCI said that the UPI system saw success rates drop to around 50 percent for two hours and hover near 80 percent for the next three hours between 11:40 am and 4:40 pm on April 12.
This latest incident, which came soon after two similar disruptions over the past two weeks, impacted most of the country’s major payment platforms—including Google Pay, PhonePe, and Paytm—as well as several banking apps. Customers attempting UPI transactions during the period were largely met with failure messages.
UPI typically operates in an “active-active-active” mode across three sites to ensure system resilience.
However, the issue on April 12 was traced back to the flooding of the “Check Transaction” API—used to verify transaction status—by certain payment service provider (PSP) banks. These banks were repeatedly sending requests, including for older transactions, without waiting for responses, which created congestion in the system, NPCI said.
"We tried to isolate the problem by eliminating sites, which is as per the standard protocol. However, this did not fully solve the problem, and we observed only a limited improvement in the success rate," NPCI said.
A temporary fix was deployed around 4:15 pm, and the success rate was restored to normal by 4:40 pm, it added.
As an immediate remedy, NPCI also asked the PSP bank responsible to halt its use of the “Check Transaction” feature.
Going forward, the organisation plans to enforce stricter rate-limiters and reiterate API usage guidelines to all PSP banks. Rate limiters are technical controls that cap how frequently banks can make API requests to the UPI system to prevent overload.
While it has so far allowed banks to manage their own use of the API based on business needs, NPCI acknowledged the need for tighter control to avoid such disruptions in the future.
Bankers in the know had earlier told ET that the disruptions were due to the massive increase in transaction volume on the payments interface in recent weeks, which they estimate is driven by a spike in gaming and betting activity.
Also Read: UPI hit by another outage, thousands of users report issues in payments
In a note to partner banks and the payments ecosystem, NPCI said that the UPI system saw success rates drop to around 50 percent for two hours and hover near 80 percent for the next three hours between 11:40 am and 4:40 pm on April 12.
This latest incident, which came soon after two similar disruptions over the past two weeks, impacted most of the country’s major payment platforms—including Google Pay, PhonePe, and Paytm—as well as several banking apps. Customers attempting UPI transactions during the period were largely met with failure messages.
UPI typically operates in an “active-active-active” mode across three sites to ensure system resilience.
However, the issue on April 12 was traced back to the flooding of the “Check Transaction” API—used to verify transaction status—by certain payment service provider (PSP) banks. These banks were repeatedly sending requests, including for older transactions, without waiting for responses, which created congestion in the system, NPCI said.
"We tried to isolate the problem by eliminating sites, which is as per the standard protocol. However, this did not fully solve the problem, and we observed only a limited improvement in the success rate," NPCI said.
A temporary fix was deployed around 4:15 pm, and the success rate was restored to normal by 4:40 pm, it added.
As an immediate remedy, NPCI also asked the PSP bank responsible to halt its use of the “Check Transaction” feature.
Going forward, the organisation plans to enforce stricter rate-limiters and reiterate API usage guidelines to all PSP banks. Rate limiters are technical controls that cap how frequently banks can make API requests to the UPI system to prevent overload.
While it has so far allowed banks to manage their own use of the API based on business needs, NPCI acknowledged the need for tighter control to avoid such disruptions in the future.
Bankers in the know had earlier told ET that the disruptions were due to the massive increase in transaction volume on the payments interface in recent weeks, which they estimate is driven by a spike in gaming and betting activity.
Also Read: UPI hit by another outage, thousands of users report issues in payments
You may also like
Was Columbia student Mohsen Mahdawi tricked to attend his citizenship interview so that he could be arrested?
'I live on a cruise ship for free - but passengers never talk about these two downfalls'
Rory McIlroy drops hint on Masters Champions Dinner menu with subtle Scottie Scheffler dig
Abhishek Chauhan calls Rajat Kapoor, 'master of subtlety'
Call of Duty returns to Xbox Game Pass in major drop featuring Modern Warfare 2 and Far Cry 4
