The App Count Is Not the Competition
Retail digital payments are the subject of this series—not payment apps considered as isolated products, but the relationship among the apps people use, the payment systems beneath them, banks, merchants, and the public authorities that shape access to those systems. The focus is a deceptively simple question: when more apps appear, do users actually gain more competitive power? The answer requires a reader to distinguish visible variety from the ability to choose, switch, and obtain better service. That distinction provides a practical way to judge digital-payment markets without mistaking growth for competition.
The question matters because digital payments are no longer a niche layer of commerce. In both advanced economies and emerging market and developing economies, households and businesses are moving more transactions onto digital systems. In advanced economies, cards account for much of the growth; in many emerging markets, account-to-account transfers are more prominent. Fast payment systems have also appeared in places such as Brazil and India, and cash in circulation has fallen more in jurisdictions that introduced them. These changes can widen access and lower the friction of paying, but they also change who controls a critical part of everyday economic life.
When digital growth hides a competition problem
Digitalisation has made payment markets more open to new kinds of provider. Fintechs offer specialized apps, big technology companies add wallets to wider ecosystems, and mobile networks support payments where traditional card use is less established. A consumer may therefore see a crowded field of brands. Yet entry into one visible layer does not necessarily displace power in another. A new app can sit on an established card network. Several apps can depend on one fast-payment rail. A merchant may accept a payment method because it reaches many customers, while customers choose it because many merchants accept it. The number of interfaces does not tell us who can reach whom or who can set the terms of access.
The Bank for International Settlements makes this distinction visible in its comparison of digital-payment markets. It describes growing contestability and new entrants, but also notes that incumbent banks and card networks retain dominant positions in important markets. Major card networks have continued to record growing revenue and high margins. In major jurisdictions excluding China, Visa and Mastercard together account for around 95 percent of card transactions, according to the Bulletin’s cited measure. This does not mean that innovation has been irrelevant. It means that new interfaces and new technologies can expand around structural power rather than replace it.
India’s Unified Payments Interface, or UPI, supplies a sharper case. The IMF describes an ecosystem that grew to more than 600 participating banks and more than 200 apps. That is an impressive expansion of formal choice. But the BIS separately reports that Google Pay and PhonePe account for 80 percent of India’s user-facing front-end market. The two figures use different measures and should not be combined: one concerns the largest group of participating institutions and apps, while the other concerns the front-end share of two named providers. Together, however, they illustrate the question this series must keep asking. An open system can host many participants while a small number of interfaces acquire substantial influence.
The practical stakes are larger than an argument about market shares. If users cannot choose an app without losing access to counterparties, then a provider’s installed base can matter more than its reliability, language support, privacy practices, or useful features. If merchants must maintain several incompatible connections, fragmentation can raise costs and weaken the value of digital payment acceptance. If a payment provider can use data, hardware access, or lending and insurance products from an adjacent business to keep users in place, competition may weaken even though transactions still pass through a common rail. And if one provider becomes the unavoidable gateway, a technical failure or commercial decision at that provider can affect a large part of the economy.
The first analytical move, then, is to stop treating an app list as a market diagnosis. A serious diagnosis asks where the payment is initiated, which system routes it, how the parties reach one another, and which rules determine whether alternative providers can participate. The same number of apps can describe either a genuinely contestable ecosystem or a set of decorative interfaces surrounding a concentrated infrastructure.
The market is a network, not a list of apps
A retail digital payment usually involves more than the screen where a person taps “pay.” The BIS describes three connected components. The user-facing front end includes the app, wallet, card, or other interface through which a household or business initiates or accepts a transaction. A back-end retail payment system routes, authorises, and clears that transaction. Behind it sits wholesale settlement among payment service providers. These components can be operated by different organizations, and competition in one does not automatically produce competition in the others.
A closed-loop payment system makes the difference intuitive. The payer and payee must use the same provider. In a wallet-based example, both hold an account or balance within that provider’s network. The more users the provider has, the more counterparties a new user can reach, so the provider becomes more attractive as it grows. This is a network effect at the level of the individual provider. It also creates a coordination problem: a person may prefer another app, but using it could mean that a desired payment is impossible. The safest choice is to join the network that other people already use, which can make early advantage difficult to overcome.
UPI changes the connection between the interface and the counterparty. The IMF describes it as an instant-payment platform built over India’s existing Immediate Payment Service infrastructure. Participating banks and third-party application providers can exchange payment messages through NPCI’s interface. In a simplified cross-app payment, the payer opens one provider’s app, the payee is reached through another provider’s app, and the relevant banks debit and credit the accounts through the shared system. The payer’s provider, the payee’s provider, the two banks, and NPCI can all have distinct roles. The user-facing app is therefore not the same thing as the payment rail or the bank holding the funds.
This arrangement is what interoperability means in practice. It is not merely a technical connector that makes two programs exchange data. It also requires common technical standards, consistent interpretation of the information exchanged, and agreement about access, clearing, settlement, failures, rights, and obligations. A payment system can be called open only if those institutional and business conditions allow the connection to work for its participants. A system may have compatible rails while an interface, merchant code, or complementary service still steers users toward one provider.
The competitive effect of interoperability follows from who must coordinate. In a closed loop, the app’s user base is part of the product because it determines the set of reachable counterparties. In an interoperable system, a user can choose among participating apps without first persuading every friend or merchant to make the same choice. Network effects do not disappear. They operate more at the level of the shared platform: the value of UPI rises when more banks, providers, users, and merchants can connect through it. That can allow the platform to grow while weakening the reason for every user to select the same front end.
This is a change in the source of competitive pressure, not a guarantee of equal outcomes. Retail payments to merchants remain a two-sided market. An app is useful to consumers when merchants accept it and useful to merchants when consumers use it. The underlying rail also has high fixed costs, network effects among participating institutions, and economies of scale in processing. Those features can support concentration even when several front ends are available. Interoperability addresses a particular barrier—the need for counterparties to coordinate on one provider—but it does not settle questions about infrastructure scale, access terms, data, reliability, or the commercial relationships built around payments.
The question this series will test
The central claim is therefore conditional. Interoperability can make digital payments more attractive by giving users freedom to choose their preferred app and by making quality differences matter. It can lower the minimum scale a new provider needs to enter, because an entrant may initially attract one subgroup while its users still transact with people on other apps. It can also pressure incumbents to improve when users can leave without losing their existing connections. These are mechanisms through which app variety can become real user value.
The UPI evidence gives those mechanisms something stronger than a purely theoretical foundation, while also showing why evidence must be read carefully. Users initially relied heavily on apps supplied by their own banks, consistent with the value of trust and familiar relationships. As the system matured, many moved toward fintech apps with additional features. The IMF also reports that a one-percentage-point lower app transaction-decline rate in one quarter was associated with about four percent higher transaction value in the next quarter, after app and time controls. That is evidence consistent with quality-sensitive choice, not a complete causal estimate of every user’s decision.
The adoption question requires another step. It is not enough to observe that UPI grew rapidly; a growing market might have expanded under a closed-loop design as well. The IMF compares UPI with a major closed-loop alternative after India’s 2016 demonetization shock. Both systems received new attention when cash became harder to use, but the closed-loop platform later plateaued while UPI continued to grow, roughly tripling between March and October 2017. Cross-app payments grew even more than within-app payments. A second comparison uses the integration of a major closed-loop provider into UPI: districts with more of that provider’s users beforehand experienced a larger increase in de facto interoperability and, in the first year, about eight additional rupees per person per month in peer-to-merchant transaction value relative to districts with less exposure. These results support a contribution from interoperability, but they do not make it the sole explanation for India’s digital-payment expansion. Cash is only partly observed, and UPI also benefited from bank-account access, digital identity, inexpensive mobile data, and other enabling conditions.
The long-run question is just as important as the launch question. An interoperable rail can still support a concentrated front end if providers issue proprietary merchant QR codes, use confusing branding, bundle payment access with lending or insurance, exploit data advantages, or gain leverage from hardware and adjacent markets. A technically cross-provider transaction may become a practical exception rather than the normal experience. The relevant measure is not simply whether a connection exists somewhere in the system, but whether users can use it easily, discover alternatives, and switch without sacrificing the relationships and services they value.
That is the judgment this series supports. To understand competition in retail digital payments, examine at least five linked questions: who controls the rail; whether users can reach counterparties across providers; whether reliability and quality attract users; whether a new entrant can grow without first reproducing an entire network; and which mechanisms may be rebuilding concentration. Adoption and innovation matter, but so do merchant costs, resilience, security, and the rules governing access. The next unresolved issue is concrete: when the payer and payee no longer need the same provider, what exactly changes in their choices—and in the incentives of the providers competing to serve them?