Green Sheet interviews the Interledger Foundation's Briana Marbury

Brazil's PIX has brought millions of consumers into the digital financial system in just a few years while giving merchants a fast, low-cost alternative to traditional payment methods. Its success has also raised questions about competition between public payment infrastructure and established card networks. Green Sheet touched base with Briana Marbury, president and CEO of the Interledger Foundation, about what drove PIX's rapid adoption, its impact on merchants and card networks, and the lessons Brazil's experience may hold for the U.S. payments industry.

Green Sheet: How did PIX achieve near-universal adoption in Brazil in just four years?

Briana Marbury: PIX achieved near-universal adoption due to Banco Central do Brasil achieving a regulatory feat before its rollout, where it required any institution with more than 500,000 active accounts to join the system from inception, while permitting smaller institutions to sign up voluntarily.

This distinction matters, as the largest banks and fintechs that held the majority of accounts were mandated to opt in from day one, giving PIX access to 90 percent of the country's account holders. 

Layered on top of this infrastructural advantage was the product's competitive advantage of fee-free transactions for consumers that settled under 10 seconds and operated 24/7, as opposed to traditional business and banking hours. Also, given PIX was available on mobile apps and a substantial portion of the population already owned smartphones, barriers to adoption were eased even further, especially for people who remained underserved by traditional banking methods.

GS: What advantages does PIX offer consumers and businesses over traditional card payments?

BM: For consumers, PIX's advantages are clear: it's faster than other methods of transacting, it's free, and it's available at any hour. This is in contrast to other payment methods that have processing delays and, in some cases, fees. The more consequential shift lies with the people who gained access to digital payment systems as a result of the implementation of PIX.

Because of the relaxed requirement to have a credit card or established credit history to participate, PIX opened up the formal financial system that previously excluded approximately 71 million underbanked Brazilians, and essentially effectuated the most significant financial access momentum the modern world has witnessed.

For businesses, and particularly small and mid-sized merchants, the advantage of PIX is its incremental cost structure. Traditional ways of accepting credit and debit card payments typically cost merchants between 1-5 percent, with debit cards being at the lower end of the spectrum. PIX, on the other hand, is a fraction of that cost, often charging merchants well below 1 percent; it is not unheard of for PIX rates to be 1/10th of traditional methods.

The liquidity implications compound this advantage, as funds transferred via PIX are in the merchants' account immediately, whereas credit cards have been known to take up to 30 days to clear.

The historical chargeback issue, where a consumer disputes a transaction and the revenue is reversed by the credit card company, is also resolved more easily through PIX, as it has established a stricter policy regarding this phenomenon. As a result, merchants find themselves in a more favorable position utilizing PIX over other payment methods. 

GS: Has PIX succeeded because it is government-backed, or because it solved problems that existing payment systems did not?

BM: The two factors are not mutually exclusive. Government backing provided the conditions to allow PIX to solve a pervasive problem at scale, while the problems themselves were a major determinant of translating mere compliance into adoption.

A simple requirement to comply with an imposed mandate is not the explanation of PIX's success, as the underlying design was aimed at removing barriers that neither credit card companies nor traditional banks had resolved. PIX fundamentally solved the problems affecting merchants and consumers alike: transaction times were too slow and too expensive.

For years, the private sector tried to address the latter two issues with failed efforts, which is why the Banco Centro do Brasil established the project in 2018. PIX succeeded where earlier attempts stalled because it was designed to address the stressors people actually experienced with the existing payment methods, then followed up with its regulatory authority to enact. 

GS: What does the U.S. criticism of PIX reveal about the future of global payments competition?

BM: In 2025 and 2026, the US Trade Representative (USTR) pursued a formal investigation into several of Brazil's trade practices, one of which concerned electronic payment services. USTR's determination held that Brazil had disadvantaged American payment companies through policies favoring PIX, which led to tariffs being imposed on Brazilian goods.

Proponents of this position argue that a state-owned payment scheme operating simultaneously as market regulator and market participant raises a structural concern, since the entity setting the rules of competition is not a neutral overseer, but an interested party.

Opponents of that framing counter that PIX did not bar Visa, Mastercard or any other network from operating in Brazil; rather, it introduced a faster, less expensive, and more accessible alternative that both consumers and merchants adopted voluntarily, which happened to be at the expense of the established card company's.

Both observations can be true simultaneously. A public option can outcompete private incumbents on its own merits while still raising governance questions worth scrutinizing, and those two considerations can be weighed differently based on the perceived appropriate role of the state in payments infrastructure.

Where this dispute becomes more broadly significant is in what it suggests about the trajectory of payments competition globally. India's UPI, a comparable state built instant payment system, now accounts for roughly 85 percent of India's domestic digital payment volume in a scale of displacement that mirrors, and in some respects exceeds, what PIX has achieved in Brazil.

The European Union, meanwhile, is pursuing its own public alternative in the digital euro, although that project remains considerably earlier in its life cycle. The European Central Bank is not targeting potential issuance before 2029 and is contingent on EU legislators finalizing the underlying regulation with a pilot program in 2027.

Together, these efforts suggest that a growing number of governments view state built payment infrastructure as a strategic asset rather than a domain to be left entirely to private card networks. 

This is a shift with real implications for incumbents like Visa and Mastercard, which may increasingly need to compete on product quality and new use cases in markets where they once faced comparatively little competition.

Whether that shift is best understood as governments correcting a market failure, or as governments tilting the playing field toward politically favored domestic champions, remains a genuinely contested question and one on which the US and Brazilian positions, unsurprisingly, diverge. 

GS: Why haven't established card networks responded more effectively to the challenges posed by systems like PIX?

BM: Established card networks have not responded effectively not for lack of recognizing the threat, but because they remain tethered to a business model whose success for decades is precisely what now constrains its adaptability. The structural features that made legacy card networks dominant are the same features that make competing with a system like PIX so difficult.

Interchange fees function as the economic engine of the entire card ecosystem: they underwrite rewards programs, absorb fraud losses and generate the returns that keep issuing banks invested in the system. Any product a network might build to compete with a free, government run, instant payment system on cost would cannibalize the very economics sustaining its existing business.

This creates a form of structural inertia, since the incentive to defend the status quo is embedded not in any single company's strategy but in the web of financial relationships linking networks, issuing banks and processors creating an ecosystem in which nearly every participant depends on interchange revenue to get paid.

Historically, card networks expanded by entering markets where no comparable alternative existed, not by underpricing a less expensive, faster competitor. In Brazil, that avenue has effectively closed as PIX now handles everyday payments more cheaply and more efficiently, and nothing on the horizon suggests that dynamic will cease to exist anytime soon.

The more viable path forward, then, is not to contest PIX transaction-by-transaction, but to migrate toward the forms of value a bank mediated network can still provide that a peer-to-peer transfer rail does not: cross-border payment infrastructure, and business facing tools such as embedded expense tracking, financial reporting, and working capital products.

Neither of these is a mature, widely deployed offering from Visa or Mastercard in the Brazilian market today, and building them out is unquestionably a harder path than seeking regulatory relief from PIX's growth. But it is the path more likely to lead somewhere, since the alternative amounts to defending a shrinking share of a business whose core economics Brazil has already demonstrated it can replicate at a fraction of the cost.

GS: What lessons should U.S. banks, payments providers and policymakers take from Brazil's experience?

BM: Brazil's experience demonstrates that a government can compress into a matter of years what has taken decades in other countries. The share of cash transactions has dramatically collapsed from roughly 43 percent to a mere 6 percent within five years of PIX's launch.

However, credit card usage did not recede alongside cash as one might expect. In fact, credit card volumes accelerated after PIX's introduction, as newly banked consumers who onboarded through PIX subsequently adopted credit products for the first time. What PIX conclusively displaced was cash and to a lesser extent, debit cards. Credit, evidently, remains a distinct value proposition even in a market with a free, instant public alternative.

The comparison to the United States' own instant payment infrastructure is instructive on the question of participation design, specifically. The Federal Reserve's FedNow Service launched in 2023 and was structured as a voluntary program left to each institution's discretion, and its adoption curve reflects that choice.

Roughly 1,800 of the nation's 9,000 eligible banks and credit unions have joined to date, with a large share only enabling the capacity to receive instant payments rather than to send them. This is not necessarily a design flaw so much as a distinct set of tradeoffs from PIX's mandatory model, where voluntary adoption disincentivizes participation from institutions with the most to lose economically.

Whether the United States should follow Brazil's approach and mandate participation in public payment infrastructure is ultimately a question about one's viewpoint on the balance between market-led versus state-led innovation. However, it must be noted that voluntary frameworks are unlikely to achieve the scale akin to PIX because the institutions best positioned to drive adoption are the exact ones with the least financial incentive to do so.

Notice to readers: These are archived articles. Contact information, links and other details may be out of date. We regret any inconvenience.