Brazil’s Pix did something regulators usually only dream of: it changed everyday behavior at national scale. Launched in late 2020 by the central bank, the account-to-account (A2A) system now dominates checkout lines and bill payments alike. On Brazil’s 2024 Black Friday, Pix set a new single-day record—nearly 240 million transfers worth about 130 billion reais—underscoring how quickly “pay by bank” has slipped into the mainstream. And in June 2025, the central bank began rolling out Pix Automático, a recurring-payments feature designed to take on direct debits and monthly bills.

Pix is not an outlier. It is the most visible node in a global migration toward instant A2A rails—systems that move money in seconds, 24/7, typically at lower cost than card networks. India’s Unified Payments Interface (UPI) has become the world’s most prolific retail payments rail, processing 16.6 billion transactions in October 2024 and surpassing 20 billion in August 2025 as functionality expanded and cross-border linkages grew. Singapore’s PayNow is already connected to UPI, letting consumers in both countries push funds to one another using phone numbers or simple aliases. The arc is clear: when real-time infrastructure is universal, cheap and embedded in bank apps, usage explodes.

Europe is now trying to compress that adoption curve. In February–March 2024, the EU formally adopted an Instant Payments Regulation obliging payment providers to let euro credit transfers arrive within 10 seconds, around the clock—and to price them no higher than conventional transfers. The goal is strategic as much as technical: build a domestic alternative that reduces reliance on non-European rails. If banks deliver on the user experience, “pay by bank” could become a default online option across the bloc.

The United States, traditionally a late adopter in retail payments, now has two domestic instant rails. The Clearing House’s RTP network has been live since 2017, and the Federal Reserve’s FedNow launched in July 2023. By mid-2025, more than 1,400 banks and credit unions were participating in FedNow, up from about 900 a year earlier—a sign that coverage, a historic bottleneck, is improving. Still, consumer behavior changes slowly: credit and debit cards remain Americans’ favorite ways to pay at the point of sale.

Southeast Asia offers a glimpse of the future when QR standards, bank apps and merchant acceptance line up. Thailand’s PromptPay handles billions of transfers each month; Bank of Thailand data show e-payment transactions (including mobile banking and PromptPay) growing briskly through 2024, with tens of millions of transfers a day. Cross-border QR links—Thailand with Singapore, and a widening ASEAN web—are turning tourists’ phones into regional wallets. BIS’s Project Nexus is pushing that vision further: a blueprint to interlink many countries’ domestic instant systems so cross-border payments can move as easily as domestic ones.

Not every country is Pix or UPI. Mexico’s CoDi, launched to nudge the economy away from cash, has struggled to break through; by 2024 only a sliver of the population had used it even once. Nigeria sits at the other extreme: its NIBSS Instant Payments rail processed over 12 billion transfers in 2024, the highest volume on the continent, as mobile-first transfers became a daily habit. These contrasts highlight a truth regulators already know: policy mandates and great technology are necessary but never sufficient. Distribution, merchant incentives and a dead-simple user journey decide winners.

So what does this wave mean for Visa and Mastercard? Start with the obvious: debit is in the crosshairs. A2A push payments replicate what debit cards do—move your money, instantly, at checkout—often at a lower acceptance cost to merchants. Fresh research and industry reports project instant payments grabbing a steadily larger piece of non-cash transactions globally over the next few years, with merchants steering shoppers to cheaper rails when they can. That dynamic is already visible in Brazil: card volumes still grow, but Pix is growing faster, and debit shows the most pressure.

The card networks are not standing still. Mastercard bought the UK’s real-time clearing operator Vocalink in 2017, giving it a footprint in ACH and instant rails. Visa has leaned into push-to-card payouts via Visa Direct, tallying billions of real-time transfers and pitching the model as globally reachable without new credentials. Both companies are also buying or partnering in open banking to power A2A checkout flows—so-called “pay by bank”—while doubling down on value-added services they can sell regardless of rail: fraud scoring, tokenization, identity, compliance and dispute mediation. In other words, they intend to be platforms, not just plastic.

Regulation adds another lever. The EU’s instant-payments rule explicitly aims to foster European alternatives to U.S. card networks, and UK authorities have been scrutinizing card fees and competition issues. In a world where lawmakers equate A2A uptake with lower merchant costs and greater sovereignty, interchange economics face a headwind, particularly on debit. The flip side is that as fraud migrates to new rails, the appetite for chargeback-like protections and risk tools rises—territory where the card schemes have decades of muscle memory.

Will cards shrink? Yes—and no. Expect debit-like spend to drift toward instant A2A where the experience is good and acceptance is visible, especially online and in bill pay. But credit is different. Revolving credit, rewards, and robust consumer protections are powerful moats that A2A rails don’t natively replicate. Some markets will graft credit onto instant rails—India already lets certain credit lines ride UPI—but the economics and risk management still rhyme with cards. For cross-border travel and e-commerce, cards’ ubiquity remains hard to beat until Nexus-style interlinks become reality and merchant tooling catches up.

The next few years will be defined less by rail-vs-rail battles than by experience and reach. If banks and fintechs make instant “pay by bank” as one-tap and rewarding as card checkout, merchants will promote it; if not, cards will keep their place. Networks that treat real-time A2A as an adjacency—selling security, identity, tokenization and dispute infrastructure on top—can prosper whichever rail wins. Brazil’s Black Friday and India’s festival season have already shown what happens when instant payments feel inevitable: money moves faster, fees come under pressure, and consumers don’t look back. For Visa and Mastercard, the moat isn’t the card—it’s the networked services that make paying and getting paid feel effortless. Those who can deliver that layer, across any rail, will own the future of checkout.