Unstable Pix in 7 Banks: What Failures Reveal About the System

On the morning of this Sunday (23), customers of at least seven major Brazilian banks faced difficulties in making transfers via Pix. According to data from the Downdetector platform, which monitors the availability of digital services, reports of failures began around 7 a.m. and peaked at 8:11 a.m., when 2,411 complaints were registered simultaneously.

Bradesco, Santander, Nubank, Caixa Econômica Federal, Itaú, Inter, and Banco do Brasil are among the affected institutions. Complaints were concentrated in three categories: mobile app (26%), transfers (25%), and QR Code scanning (25%). The Central Bank, responsible for the Pix infrastructure, has not commented at the time of publication.

When Pix Fails, the Country Feels It

Pix processes, on average, more than 200 million transactions per day, according to data from the Central Bank. It is the most used payment method in Brazil, surpassing bank slips, TEDs, and even physical cash in various categories of everyday spending. When it fails, even for a few hours on a Sunday morning, the impact is immediate: from app rides to purchases at bakeries, including transfers between individuals.

On social media, users reported difficulties in paying for rides and making basic purchases. Itaú's official account on X (formerly Twitter) acknowledged the instability and informed that teams were working to resolve the issue. Bradesco, in turn, asked customers to try accessing the service later.

This episode is not isolated. As we have followed in the finance coverage of the portal, sporadic failures in Pix have become more frequent as the volume of transactions has grown exponentially in recent years. In November of last year, the system also experienced widespread instability, sparking debates about the infrastructure's capacity to keep up with demand.

Centralized Infrastructure, Concentrated Risk

Pix operates on the Instant Payment System (SPI), maintained by the Central Bank. Unlike a decentralized network, all settlements go through a single infrastructure. This ensures speed and interoperability among banks but creates a single point of vulnerability. If the SPI experiences slowness, all participants suffer at the same time.

It is important to distinguish: the failure can occur at the SPI level (BC infrastructure) or in the internal systems of each bank. When seven institutions experience problems simultaneously, the likelihood that the origin lies in the central layer increases. Still, without an official statement from the Central Bank, it is not possible to confirm the root cause.

The centralized model has clear merits. Pix has managed to bank millions of Brazilians and significantly reduce transaction costs. The massive adoption of the system is a global success story in instant payments. But episodes like this Sunday expose the need for continuous investment in redundancy and capacity.

What Banks and the Central Bank Need to Answer

Three questions remain unanswered satisfactorily after each episode of instability. First: what is the contingency plan when Pix goes down? For the end user, there is no comparable instant and free alternative. TED does not work on weekends. Bank slips take days. Physical cash requires prior withdrawal.

Second: does the Central Bank monitor and publish real-time availability metrics for the SPI? So far, there is no public dashboard that allows citizens to track the system's status, something that technology companies like AWS and Google Cloud have offered for years for their services.

Third: is the infrastructure sized for projected growth? The Automatic Pix, expected to expand the system's use to recurring payments, will add a considerable volume of transactions. As we analyzed about the Automatic Pix, the functionality has the potential to replace automatic debits and bank slips, but it requires the technological base to support the additional load without compromising stability.

A Lesson in Resilience for the Financial System

This Sunday’s episode lasted a few hours and, for most users, was a temporary inconvenience. But the increasing frequency of these failures deserves attention. A system that has become critical infrastructure for the Brazilian economy needs availability standards compatible with this responsibility.

Central banks around the world face a similar challenge. FedNow, the United States' instant payment system launched in 2023, also operates on a centralized model and is already facing questions about scalability. India, with the UPI (Unified Payments Interface), deals with volumes even larger than Pix and invests heavily in infrastructure redundancy.

For Brazil, the question is not whether Pix is a good system. That has already been proven. The question is whether the investment in resilience keeps pace with the adoption rate. With over 160 million registered users and a growing share of the country's transactional GDP, every minute of unavailability has a real economic cost.

The Central Bank has been competent in innovating Pix, adding functionalities like Pix by proximity and Automatic Pix. Now it needs to demonstrate the same competence in reliability engineering. Transparency about incidents, public uptime goals, and agile communication during failures would be first steps in the right direction.