In June 2023, India’s Unified Payments Interface crossed 9.4 billion transactions in a single month — a number that would have seemed like science fiction just a decade ago. By FY2024, UPI was processing over $2 trillion in annual transaction value, making it one of the most consequential financial infrastructure stories in modern history. But the true significance of UPI extends far beyond its transaction volumes. It represents something more profound: proof that the right payment infrastructure, built on open APIs and interoperable standards, can leapfrog decades of financial inertia and bring hundreds of millions of people into the formal economy almost overnight.
The story of UPI is not just an Indian story. It is a blueprint — one that emerging markets across Asia, Africa, Latin America, and Southeast Asia are studying closely as they build the next generation of payment rails.
The Architecture of a Revolution
UPI was not born in a vacuum. It was built on a carefully designed set of open APIs that allowed any bank, fintech company, or non-banking business to plug into the same underlying payment rails. The National Payments Corporation of India (NPCI) engineered UPI as an interoperable system — meaning a user on PhonePe could seamlessly send money to someone on Google Pay or a bank’s own UPI app. This interoperability was not an accident. It was a deliberate design choice, and it is the reason UPI scaled so rapidly across an enormously diverse country.
The API-first approach meant that businesses did not need to build their own payment infrastructure from scratch. They could integrate with a standardised set of UPI APIs, go live within weeks, and immediately access the full network of participating banks and hundreds of millions of users. This dramatically lowered the barrier to entry — from a street vendor accepting QR code payments to a large enterprise running automated payroll disbursements.
What UPI demonstrated, more than anything else, is that payment infrastructure APIs are not a convenience. They are a competitive and economic necessity.
The Global Emerging Market Opportunity
Zoom out beyond India, and the picture is both exciting and urgent. According to the World Bank, roughly 1.4 billion adults globally remain unbanked, with the vast majority concentrated in Sub-Saharan Africa, Southeast Asia, and Latin America. Yet mobile penetration in these regions has significantly outpaced traditional banking infrastructure. This gap — between mobile access and financial access — is precisely where payment infrastructure APIs come in.
In Brazil, Pix, the instant payment system launched by the Banco Central do Brasil in 2020, has crossed 150 million registered users and processes billions of transactions monthly — following a strikingly similar model to UPI. In Nigeria, a growing API ecosystem is enabling fintechs to build payment products at speed on top of existing banking rails. Across Southeast Asia, cross-border QR linkages between Thailand, Malaysia, and Indonesia are creating a regional payment fabric powered by standardised APIs.
The common thread running through all of these developments is API-enabled interoperability. Countries are increasingly recognising that payment infrastructure must be built like a utility — open, standardised, and accessible to every business and developer through well-documented, developer-friendly interfaces.
What Payment APIs Actually Unlock for Businesses
For businesses operating in or entering emerging markets, payment APIs are not just a technical integration — they are a strategic unlock. Here is what they enable that was previously either difficult, slow, or prohibitively expensive:
Real-time fund flows. Traditional bank transfers could take up to two business days to settle. Payment APIs built on modern rails like UPI settle in seconds, around the clock, every day of the year. For businesses managing vendor payments, salary disbursements, or customer refunds, this changes cash flow management entirely.
Automated collections. Through UPI mandates and equivalent standing instruction frameworks in other markets, businesses can automate recurring collections — subscription fees, EMI repayments, insurance premiums — without requiring manual intervention each cycle. This reduces operational overhead while meaningfully improving collection rates.
Multi-rail flexibility. Modern payment API platforms support multiple rails — UPI, NEFT, RTGS, IMPS — under a single integration. Businesses can route payments through the most appropriate rail based on factors like transaction size, urgency, and cost, without rebuilding their infrastructure each time a new rail needs to be supported.
Embedded payment experiences. Perhaps most importantly, payment APIs allow businesses to embed payment capabilities natively within their own product — without redirecting users to a third-party checkout page. This creates seamless in-product financial experiences that improve both conversion rates and customer retention.
Platforms like Decentro have built their entire product philosophy around this idea — providing businesses with a modular stack of banking and payment APIs that allow them to integrate financial services into their core workflows without having to build or maintain the underlying infrastructure themselves.
The Infrastructure Layer Businesses Are Building On
As more businesses recognise the value of payment APIs, a new category of infrastructure providers has emerged — companies that aggregate, standardise, and simplify access to multiple payment rails through a single, developer-friendly API layer.
This matters because accessing payment rails directly — through individual bank integrations or NPCI partnerships — remains complex, time-consuming, and expensive. Most companies, particularly startups and mid-market businesses, do not have the resources to manage a dozen separate banking integrations while simultaneously building their core product. An aggregated API platform solves this by abstracting the complexity and presenting a unified interface.
Consider a fintech startup launching a lending product in India. It needs to collect loan repayments, disburse approved funds, and verify borrower bank accounts — each of which requires a different banking or payment integration. Rather than building these connections individually, the startup can use UPI Autopay APIs to handle collections through UPI mandates and automate disbursements through IMPS or NEFT — all from a single API stack. What was once a six-month infrastructure build compresses into weeks.
This is why an increasing number of neobanks, embedded finance players, lending platforms, and B2B SaaS companies are choosing to build on top of BaaS API platforms rather than going directly to banks.
From Domestic Rails to Cross-Border Corridors
The next frontier for payment infrastructure APIs is cross-border payments. UPI has already made significant strides here. In February 2023, India and Singapore launched a real-time cross-border payment link connecting UPI with Singapore’s PayNow — allowing users on either system to make instant, low-cost transfers across borders. India has since extended similar linkages to the UAE, France, Mauritius, Bhutan, and Nepal.
This is the early shape of what could become a global network of interoperable, API-driven payment corridors — where a business in India can pay a supplier in Kenya, or a freelancer in the Philippines can receive a salary from a company in Germany, all in real time and at near-zero marginal cost.
For emerging market economies, the stakes are significant. Cross-border remittance flows remain a financial lifeline for millions of households, yet the World Bank estimates that the average cost of sending $200 internationally still exceeds 6%. API-enabled, real-time payment rails have the potential to drive this cost dramatically lower over the coming decade — making remittances faster, cheaper, and more transparent for the people who depend on them most.
Conclusion
UPI did not merely build a faster payment system. It proved that a well-designed, API-first payment infrastructure can restructure an entire economy’s relationship with money — faster than traditional banking expansion, faster than top-down regulation, and faster than anyone had predicted. The emerging markets paying close attention are not simply looking to clone UPI. They are looking to adapt its core principle: that open, interoperable, API-driven payment infrastructure is the fastest path from financial exclusion to full financial participation.
For businesses, developers, and fintechs building across these markets, the opportunity is clearer than ever. The rails are being laid. The APIs are being published. The question is no longer whether to integrate — it is how quickly you can get on board.
