Pix MED Brazil: the Central Bank's special return mechanism

By June 2025, Brazil's Central Bank had recorded about R$ 1,4 bilhão returned through Pix MED [Voto 105/2025, § 3, PDF p. 1]. The Special Return Mechanism freezes a seller's revenue when the payer's PSP alleges a scam. For an international ISV, meaning an Independent Software Vendor, selling software into Brazil and accepting Pix, that is a cash risk, not a minor compliance detail.

What is Pix MED, and why does an ISV selling in Brazil need to understand it?

Pix MED is the Special Return Mechanism established by Brazil's Central Bank to return a Pix transaction when there is a well-founded suspicion of fraud or an operational failure [Voto 105/2025, § 1, PDF p. 1]. For an international ISV selling licenses or software services in Brazil, the mechanism can freeze revenue that the business already treated as received. The sale is not economically final merely because the Pix credit appeared.

The mechanism formally entered the Pix Regulation through BCB Resolution No. 103, dated 8 June 2021, with effect from 1 November of that year and operational effects from 16 November 2021 [Voto 119/2021, PDF p. 4 and draft art. 3, PDF p. 10]. Pix itself launched on 16 November 2020. During its first year, there was no structured MED, only precautionary blocking mechanisms. The MED is therefore a later control built around the payment system, not a feature that existed from its launch.

That distinction matters to an international software vendor because Pix adoption gives the payment method commercial value while fraud creates a separate settlement exposure. Pix became Brazil's most used payment method, and the volume of fraud grew with that scale. From the mechanism's effective date through June 2025, the Central Bank recorded about R$ 1,4 bilhão returned to fraud victims through MED [Voto 105/2025, § 3, PDF p. 1]. The number describes funds returned to victims, but it also tells the seller how much money has already moved through this mechanism.

The operational question is simple: when a Brazilian customer says a Pix payment resulted from a scam, which institution can touch the seller's balance, and how quickly? The answer is not found in the seller's checkout screen. It sits in the relationship between the payer's PSP, the receiving user's PSP, and the contracts governing the seller's account.

Who activates Pix MED when a scam occurs?

The payer's financial institution activates MED, not the seller [Voto 105/2025, § 2, PDF p. 1]. When the user who claims to be a scam victim complains, the payment issuer PSP opens Value Recovery in DICT. DICT then automatically creates fraud notifications for the institutions serving the users who received the funds [Guia MED v4.3, § 4.2.4, step 2 and step 3, PDF p. 14].

The seller does not activate MED.

That allocation creates the central asymmetry. The creditor, merchant, or software vendor that received the Pix does not control the opening of the mechanism. It is the protected party in the alleged fraud claim, but its balance can still be blocked and debited. The receiving user's PSP carries out the financial execution by debiting its customer's account and returning the funds to the paying user [Guia MED v4.3, § 4.2.4, step 10, PDF p. 16]. In the ordinary scam flow, the payer's PSP opens the process and the institution holding the funds applies the debit.

Participants in the payment arrangement must include contractual clauses allowing blocking and debit without a new, transaction-specific authorization [Guia MED v4.3, section 4, PDF p. 8]. The Central Bank's guidance says participants should not ask the customer whether they agree with the return. They should apply the contractual provision already in place [Guia MED v4.3, section 4, PDF p. 8].

For the international ISV, this is the practical change in mindset: a Pix credit is a provisional commercial outcome when the payment can enter a MED process. Revenue recognition, cash forecasting, reserves, and customer support should reflect the processor's contractual treatment of blocking, reserve, debit, and settlement.

What happens to the seller's balance during MED?

When the receiving user's PSP receives the fraud notification, it must immediately block the amount identified in that notification [Guia MED v4.3, § 4.2.4, step 3, PDF p. 15]. If the account balance is smaller, the PSP blocks all available funds. New credits entering the account after the block remain held until the requested amount is reached [Guia MED v4.3, § 4.2.4, step 3, PDF p. 15].

The block is proportional to the disputed amount. It equals the original transaction value or the amount stated in the notification, which cannot exceed the transaction value. If several notifications relate to the same transaction, the total block cannot exceed the originating transaction amount [Guia MED v4.3, § 4.2.4, step 3, PDF p. 15]. MED does not authorize a retention larger than the revenue being disputed.

The review period lasts up to 7 dias corridos [Guia MED v4.3, § 4.2.4, step 5, PDF p. 15]. During that window, the receiving user's PSP examines whether its customer committed the alleged fraud, scam, or crime. The seller supplies evidence that the transaction was legitimate, such as delivery records, a signed contract, and invoices. At the end of the review, the receiving user's PSP accepts or rejects the fraud notification.

The point that sellers often miss is what follows rejection. If the receiving user's PSP rejects the notification, it unblocks the funds and becomes responsible for the return if real fraud is later established [Guia MED v4.3, § 4.2.5, PDF p. 18]. The return risk does not vanish when a notification is rejected. For a period, it moves from the seller's account to the balance sheet of the institution that chose to reject the fraud marking.

A digital software sale makes the evidence question more demanding. A customer can say that access failed, that the service was not delivered, or that the payment resulted from fraud. Those are different assertions, and the processor needs records that distinguish them. A login event, API call history, license consumption, account activation, and dated service delivery record can connect the payment to actual use.

What is the seller's role during a return?

The seller's role in MED is limited and indirect. The seller does not decide the outcome. It proves to its own receiving user's PSP that the transaction was legitimate, while that PSP accepts or rejects the notification using the documentation supplied [Guia MED v4.3, § 4.2.4, step 5, PDF p. 15].

In practice, the seller's process has five steps:

1. Learn from the PSP, through an account notification or another communication, that a payment has been blocked because of suspected fraud.
2. Gather evidence that the sale was legitimate: the order, contract, service delivery record, account activation, and software usage history.
3. Submit the documents to the receiving user's PSP within the 7 dias corridos review window [Guia MED v4.3, § 4.2.4, step 5, PDF p. 15].
4. Wait for the institution's decision to accept or reject the fraud notification.
5. Receive the outcome: the funds are returned to the payer and the block remains, or the funds are released and the block is removed.

Software vendors should build this evidence before an incident, not after a notification arrives. The strongest record is usually proof of real use: a login timestamp, API consumption, an activated seat, or a license event tied to the customer account. An invoice dated before the dispute helps establish the commercial sequence, but an invoice alone does not show that the customer used the software.

If the seller believes the debit was improper, it can contest the return transaction under the applicable MED flow for an improper MED opened because of fraud by the paying user [Guia MED v4.3, § 4.2.5, PDF p. 18]. The paying user's dispute against its own PSP is a separate route. The contract and the PSP's current procedure determine how that route works.

Is Pix MED the same as a card chargeback?

Treating MED as Pix's version of a card chargeback is understandable, but the Central Bank expressly distinguishes them. The BCB MED Guide states that MED is not a chargeback mechanism like the one used in payment card arrangements [Guia MED v4.3, § 4.2.3, PDF p. 13]. The legal rule, trigger, evidence burden, and appeal setting differ.

The first difference is the burden of proof. In Pix, it is not enough for the paying user to say that the transaction was unrecognized. The process requires proof that the receiving seller was the agent of the fraud, scam, or crime [Guia MED v4.3, § 4.2.3, PDF p. 13]. That threshold is materially different from a card dispute based on the card arrangement's rules.

The second difference is the governing arena. A card chargeback follows the rules of card networks and card arrangements, which are private and international, with timelines that vary by country, issuer, and case type. MED follows Brazil's Pix Regulation and the Central Bank's procedures, including a standardized review period of 7 dias corridos [Guia MED v4.3, § 4.2.4, step 5, PDF p. 15].

For an international ISV, the distinction affects both evidence design and contract review:

The boundary is equally important. A commercial disagreement, such as late delivery, a service that did not meet the buyer's expectation, or ordinary buyer's remorse, falls outside MED [Guia MED v4.3, § 4.2.3, PDF p. 13]. Funds that reached a good-faith third party cannot be debited [Guia MED v4.3, § 4.2.3, PDF p. 13]. A payer's own mistake, such as sending funds to the wrong recipient or sending the same payment twice, is not returnable fraud through this route [Guia MED v4.2.3, PDF p. 13]. Those cases belong to the courts or to the commercial terms of the contract.

What does MED 2.0 change in practice?

Voto 105/2025-BCB, dated 27 August 2025, describes the MED operating since November 2021 and proposes tracing fraud beyond the first receiving account [Voto 105/2025, §§ 1 and 3-4, PDF pp. 1-2]. The earlier process reached the immediate recipient of the fraud. Its tracking stopped at the first account.

MED 2.0 adds Value Recovery in DICT, which traces fraudulent transactions beyond the first receiving account by following the path through subsequent transactions [Voto 105/2025, §§ 3-4, PDF pp. 1-2]. The purpose is to identify how funds were dispersed and enable blocking and return directly to the victim's account, even when the money passes through multiple institutions. When a pass-through account is identified, the receiving user's PSP debits its customer's account and performs the transaction to the paying user in its own name [Voto 105/2025, § 4, PDF p. 2].

End-to-end tracing between PSPs changes the seller's risk calculation in two ways. First, it reduces the historic advantage a scammer gained by dispersing funds across third-party accounts [Voto 105/2025, §§ 3-4, PDF pp. 1-2]. Second, the process reaches subsequent transactions rather than stopping at the first account. A good-faith seller cannot have its account debited merely because MED exists [Guia MED v4.3, § 4.2.3, PDF p. 13]. Tracing does not turn a good-faith third party into a confirmed fraud participant.

MED 2.0 also standardized timing and added automatic blocking. Since October 2025, the Pix key associated with the fraudster's account in a fraud notification is automatically blocked. The account can no longer move funds through Pix, which eliminates multiple blocks and partial returns [Guia MED v4.3, question 32, PDF p. 38; Pix Regulation, art. 89, § 2, cited in that answer]. The schedule in Guia MED v4.3 is 7 days of review by receiving users' PSPs, 72 hours after those 7 days for the payer's PSP to initiate the return, and 6 hours for each receiving user's PSP to make its payment sequentially [Guia MED v4.3, § 4.2.4, PDF p. 17].

Adoption was phased. The functionality became optional on 23/11/2025 and mandatory from 02/02/2026 for participants operating as transaction-account providers and special settlement institutions [Voto 105/2025, § 9, PDF p. 3]. Those dates belong in the seller's operational calendar because a processor's MED procedure may change during an active customer dispute.

How should MED risk affect the decision to accept Pix?

Pix remains inexpensive and converts quickly in the Brazilian checkout. The credit received is not zero-risk. The international ISV must understand its processor's contractual rules for blocking, reserves, debits, and settlement, because the processor's operating design determines how a confirmed fraud affects cash flow and evidence handling.

The commercial case for local currency remains strong. The cost of local payments for SaaS sales in Latin America explains why local currency can improve acceptance, while the local checkout guide for international SaaS addresses the conversion side. Neither benefit removes MED exposure. They answer a different question: whether Brazilian buyers are more likely to complete the purchase.

Three operating practices reduce exposure. First, create a record of actual service use for every material transaction: login activity, license consumption, API calls, account activation, and delivery evidence. That record supports the seller's position during the 7 dias corridos review. Second, keep commercial documents in order, including contracts and invoices issued with the correct dates and before the dispute. Third, use a local payment processor that fulfills MED obligations and communicates a block clearly and quickly.

The third practice is where infrastructure matters. An international ISV that processes Pix through a PSP already operating under Brazilian rules has a defined path for notifications, evidence, blocking, return, and communication. An ISV that accepts Pix without knowing which institution is the receiving user's PSP, who holds the balance, or which contractual clause governs a debit has accepted an operational risk it cannot measure.

Nexforce Marketplace is relevant as a local software distribution and payment route, not as a promise that fraud disappears. It gives an international ISV access to local infrastructure without opening a Brazilian entity, with no cost to the ISV, no minimum deal size, and full LatAm coverage. The route supports region-friendly methods such as PIX, boleto, local cards, and installments. Nexforce pays the ISV upfront while the end client can pay in installments up to 12x, so the vendor does not carry the buyer's receivable.

The product also accepts the ISV's own contract standard and programs, avoids a required commitment to a particular cloud, and offers a reseller network. Its software alliance can generate savings on the buyer's other software spend, which can make an otherwise difficult deal viable. These are distribution and working-capital benefits. They do not decide the legal role of a processor or allocate the economic loss in a MED case.

The decision to accept Pix should therefore examine more than the acceptance fee. The useful questions are who receives the notification, who gathers the evidence, how quickly a rejected block is released, and what happens when the disputed balance is unavailable. An international ISV selling into Brazil needs a predictable receiving-side process, not a claim that the payment method has no fraud risk.

What should an international ISV ask its payment processor?

Before accepting Pix, the international ISV should ask the processor how it handles a fraud notification, evidence, blocking, release, and an accepted return. The answers reveal whether the processor manages the MED workflow or simply passes an uncertain debit through to the vendor. They also expose which obligations belong to the contract rather than to the article.

The first question is how the processor handles a fraud notification. Does it present the evidence for the seller, or must the seller submit documents case by case? The second is the block and release policy: after a notification is rejected, how long does it take for the funds to become available again?

The third question is whether the processor retains transaction and dispute history so the seller can audit what was blocked, released, or returned. The fourth is whether there is a documented workflow, with deadlines, for cases covered by the Pix Dispute Resolution Manual.

The fifth question concerns economic responsibility when a notification is accepted in favor of the payer. Operational responsibility can vary with the notification result, available balance, and actions of each PSP. The seller should request the contractual rule for an upheld return, an insufficient balance, and a rejected notification. This article does not determine who bears the economic loss.

The honest starting point for most international ISVs is that Pix combines high payment efficiency with a strict return mechanism. No intermediary eliminates fraud risk. The right decision is not to avoid Pix by default. It is to choose an infrastructure where a fraud event has a documented, testable process on the receiving side.

Frequently asked questions

These five answers restate the positions supported by Guia MED v4.3 and Votos 119/2021 and 105/2025 from Brazil's Central Bank, with PDF pinpoints in the body. They give an international ISV a quick way to explain Pix cash risk to a finance team or board. They do not replace the contract with the payment processor.

What is Pix MED?

Pix MED is the Central Bank's Special Return Mechanism. It returns funds from a Pix transaction when there is a well-founded suspicion of fraud or an operational failure [Voto 105/2025, § 1, PDF p. 1]. It entered the Pix Regulation through BCB Resolution No. 103/2021, with effects from 16 November 2021 [Voto 119/2021, PDF p. 4]. For an ISV, the risk is that already credited revenue can be frozen.

Who activates Pix MED, and what happens to the balance?

The payer's PSP opens Value Recovery in DICT [Guia MED v4.3, § 4.2.4, PDF p. 14]. The receiving user's PSP immediately blocks the identified amount, proportional to the transaction [Guia MED v4.3, § 4.2.4, step 3, PDF p. 15]. Review lasts up to 7 dias corridos [Guia MED v4.3, § 4.2.4, step 5, PDF p. 15]. The seller submits evidence of legitimacy to its own PSP.

Is Pix MED a card chargeback?

No. Guia MED v4.3, § 4.2.3, PDF p. 13, states that MED is not a chargeback mechanism used by card arrangements. Pix requires proof of fraud, scam, or crime by the receiving seller. Commercial disagreement, buyer's remorse, and sending funds to the wrong recipient fall outside MED.

What does MED 2.0 change in practice?

Voto 105/2025-BCB, §§ 3-4 and 9, PDF pp. 1-3, describes Value Recovery in DICT, which traces fraud beyond the first account. The functionality became mandatory on 02/02/2026 for transaction-account providers and special settlement institutions [Voto 105/2025, § 9, PDF p. 3].

Can the seller reverse the debit through the Central Bank?

No. The seller has no formal direct appeal to the Central Bank inside MED. If the seller believes the debit was improper, it can contest the return transaction under the Guia MED flow for an improper MED opened because of fraud by the paying user [Guia MED v4.3, § 4.2.5, PDF p. 18]. The paying user's dispute against its own PSP is a separate route.

References and further reading

Primary sources. The items below are instruments of Brazil's Central Bank. Each citation in the article points to a resolution, vote, or section and page of the extracted PDF. The original source should govern operational decisions.

1. Central Bank of Brazil. BCB Resolution No. 1, dated 12 August 2020. Establishes the Pix payment arrangement and approves its Regulation. https://www.bcb.gov.br/estabilidadefinanceira/exibenormativo?tipo=Resolução%20BCB&numero=1
2. Central Bank of Brazil. BCB Resolution No. 103, dated 8 June 2021. Introduces the Special Return Mechanism into the Pix Regulation. https://www.bcb.gov.br/estabilidadefinanceira/exibenormativo?tipo=Resolução%20BCB&numero=103
3. Central Bank of Brazil. Voto 119/2021-BCB, dated 2 June 2021. Statement of reasons for creating MED. https://normativos.bcb.gov.br/Votos/BCB/2021119/Voto_do_BC_119_2021.pdf
4. Central Bank of Brazil. Voto 105/2025-BCB, dated 27 August 2025. Statement of reasons for MED 2.0 and Value Recovery. https://normativos.bcb.gov.br/Votos/BCB/2025105/Voto_do_BC_105_2025.pdf
5. Central Bank of Brazil. BCB Resolution No. 493, dated 28 August 2025. Normative page for the MED 2.0 framework. https://www.bcb.gov.br/estabilidadefinanceira/exibenormativo?tipo=Resolução%20BCB&numero=493
6. Central Bank of Brazil. Guide to implementing Pix return procedures, with emphasis on MED, version 4.3, history dated 07/07/2026. https://www.bcb.gov.br/content/estabilidadefinanceira/pix/Guia_MED.pdf
7. Central Bank of Brazil. BCB Resolution No. 546, dated 22 January 2026. Normative page for the current Pix framework. https://www.bcb.gov.br/estabilidadefinanceira/exibenormativo?tipo=Resolução%20BCB&numero=546

All sources accessed on 28 August 2026.

What this analysis does not cover, and the seller's next step

This analysis is preliminary. MED changed after MED 2.0. The framework sits in BCB Resolutions No. 1/2020, 103/2021, 493/2025, and 546/2026, together with the BCB MED Guide. Figures and timelines in this article come from the extracted PDFs, including Guia MED v4.3 and Votos 119/2021 and 105/2025. Claims not confirmed by primary sources were left out.

This content is not legal or tax advice. The tax position and intermediary position of any distributor are outside its scope. For contract and operational decisions in Brazil, each fraud and return case should be reviewed by counsel experienced in Brazilian payment methods. The guide to preventing chargebacks in cross-border SaaS adds the broader fraud perspective for a vendor operating across currencies and payment methods.

Pix is now a pillar of Brazilian digital commerce, and MED is a variable an international seller must price into the payment decision. The mechanism protects a citizen who was defrauded, while the seller must preserve evidence and understand the receiving-side procedure before accepting the method. Nexforce Marketplace documents local Pix payment with an invoice in BRL. This article does not determine the processor's legal role, MED obligations, loss allocation, or tax position. It does not replace the PSP contract or the MED dispute design.