NPCI Instructs Banks to Limit 'Check Transaction' API Calls to Prevent Future UPI Outages

The National Payments Corporation of India (NPCI) has issued a directive to all banks to restrict the use of the ‘Check Transaction’ API after a major service outage affected UPI transactions on April 12, 2025.

What Caused the UPI Outage?

On April 12, UPI services across the country were severely disrupted for over five hours, from 11:40 AM to 4:40 PM.
The reason behind the outage was a massive surge in transaction status queries sent by banks, which overwhelmed the system.

"The spike in API calls overwhelmed the system, leading to a sharp drop in transaction success rate."

As a result, UPI success rates reportedly dropped to around 50%, impacting millions of users nationwide who rely on UPI for real-time payments.

NPCI’s Revised Protocol for API Usage

To prevent further disruptions, National Payments Corporation of India (NPCI) has instructed banks to modify their usage of the 'Check Transaction' API with strict timing controls.

New API Call Guidelines:

"Banks must delay their first ‘Check Transaction’ API call until at least 90 seconds after the transaction is initiated or authenticated."

• Subsequent API calls should be spaced 45 to 60 seconds apart.

• A maximum of three API checks is allowed within a two-hour window after the transaction.

• PSP banks must also regulate repeated API requests to avoid system overload.

“Payment service provider (PSP) banks have also been asked to moderate all API traffic to avoid unnecessary repeat calls for the same transaction.”

Audit Requirements and Long-Term Safeguards

NPCI has made it mandatory for banks to undergo system audits by CERT-In empanelled auditors to review how APIs are used and how systems behave during high-load periods.

"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."

These audits are to be conducted annually to ensure compliance and resilience of the system.

UPI’s Role in India's Digital Payment Ecosystem

Unified Payments Interface (UPI), created by the National Payments Corporation of India (NPCI), stands as the most widely used real-time digital payment system in the country. Handling more than 10 billion transactions each month, it plays a vital role in powering India's digital economy.

About National Payments Corporation of India (NPCI)

The National Payments Corporation of India (NPCI) is the umbrella organization that operates retail payments and settlement systems in India. Established in 2008 as a "not-for-profit" company under Section 8 of the Companies Act 2013, NPCI was initiated by the Reserve Bank of India (RBI) and the Indian Banks' Association (IBA) under the provisions of the Payment and Settlement Systems Act, 2007.

Its primary goal is to create a robust, secure, and efficient payment infrastructure in the country, promoting a less-cash economy and enhancing financial inclusion.

Key Objectives of NPCI:

• To provide affordable and robust payment systems for the common person.

• To integrate various payment systems into nationwide uniform and standard business processes.

• To improve operational efficiency and expand the reach of retail payment systems through innovation and technology.

Key Functions of NPCI:

• Design and Development of Payment Systems: NPCI is responsible for creating and operating key payment systems in India, including UPI, IMPS, RuPay, NACH, and BBPS.

• Interbank Settlement: It acts as an intermediary for settling interbank transactions, ensuring the smooth transfer of funds.

• Setting Rules and Guidelines: NPCI prescribes the rules, regulations, and guidelines for the operation of its various payment systems.

• Approving Participants: NPCI approves the participation of banks, Payment Service Providers (PSPs), and Third-Party Application Providers (TPAPs) in its systems.

• Ensuring Security and Efficiency: NPCI is committed to providing a safe, secure, and efficient payment infrastructure.

• Dispute Management: It plays a role in dispute resolution for transactions processed through its systems.

• Promoting Financial Inclusion: NPCI develops payment solutions that cater to the underbanked and unbanked populations.

Major Initiatives by NPCI:

• Unified Payments Interface (UPI): A real-time payment system allowing users to transfer funds instantly between bank accounts using a mobile phone.

• RuPay: India's domestic card scheme, offering debit, credit, and prepaid cards.

• Immediate Payment Service (IMPS): Enables instant fund transfers between banks 24/7.

• Aadhaar enabled Payment System (AePS): Allows financial transactions using Aadhaar authentication.

• National Automated Clearing House (NACH): Facilitates bulk transactions like salary payments and utility bill collections.

• Bharat Bill Payment System (BBPS): An integrated platform for paying various utility bills.

• National Electronic Toll Collection (NETC): Uses FASTags for automatic toll payments.

• BHIM (Bharat Interface for Money): A UPI-based mobile payment application developed by NPCI.

• UPI Lite: An on-device wallet for small-value UPI transactions.

NPCI has been instrumental in revolutionizing the digital payments landscape in India, making transactions faster, more accessible, and secure. Its continuous focus on innovation and financial inclusion has positioned India as a leader in digital payments globally.