MED

Learn how the Pix MED process handles fraud, unauthorized transactions, and operational errors under BACEN deadlines, with pacs.004 refunds through SPI.

MED (Mecanismo Especial de Devolução) is the special refund mechanism of the Central Bank of Brazil (BACEN). It defines how institutions investigate a disputed Pix transaction, communicate with each other, decide the outcome, and execute a refund.

MED is mandatory and follows one standard. It protects the consumer and keeps the process consistent and auditable across every institution.

When MED applies

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A Pix transaction enters the MED process when a financial institution needs a formal, regulated investigation. Common cases include:

• Fraud (phishing, account takeover, social engineering)
• Unauthorized transactions (the user did not approve the payment)
• Operational errors (duplicate sends, wrong recipient, wrong amount)
• System or processing failures that cause financial impact

MED runs independent of the standard Pix refund flows. A standard refund is voluntary. MED is mandatory and follows BACEN rules.

Regulatory MED lifecycle

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Every MED case runs as an infraction report with a fixed set of states. The report opens as OPEN, moves to ACKNOWLEDGED, and ends as CLOSED or CANCELLED. Each state carries its own BACEN deadline and response requirement.

Lifecycle overview

Figure 1. MED infraction-report lifecycle stages and transitions

Integration points

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MED is a regulatory process, but it works with the core Pix components:

Component	Role
DICT	Provides fraud markers, key metadata, and ownership information
SPI (pacs.004)	Executes the refund movement between institutions
Midaz Ledger	Records the balance movements when a refund settles
Pix Switch services	Coordinate the case lifecycle, deadlines, and notifications

Compliance expectations

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An institution that runs MED must:

• Meet every regulatory deadline
• Keep a full audit trail with timestamps and event logs
• Send standardized MED messages to the counterpart institution
• Track each case status and its SLA
• Notify the customer consistently
• Use the correct dispute categories and reason codes

Relationship with refunds and reversals

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A refund and a reversal are standard Pix operations. MED provides the regulated mechanism for these cases:

• The refund is tied to fraud or unauthorized activity
• The originating institution disputes the transaction
• The case needs extra evidence and regulated communication

In these cases, the MED decision drives the refund. The institution does not process it as a voluntary action.

Infraction reports

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An infraction report is the formal way a Pix participant reports suspected fraud or unauthorized activity on a transaction. It is the entry point of the MED dispute-resolution process.

When to file an infraction report

A Pix participant files an infraction report when a customer reports fraud or unauthorized activity. The report names the counterparty and starts the investigation. Pix Switch receives the report as the counterparty. It can also cancel a report that it filed as the reporter.

An infraction report carries a situation type that classifies the dispute:

Situation type	Meaning
SCAM	The customer was tricked into authorizing the payment
ACCOUNT_TAKEOVER	A third party took control of the account
COERCION	The customer paid under coercion
FRAUDULENT_ACCESS	The payment came from unauthorized channel access
OTHER	Another situation, described in the report details
UNKNOWN	The situation is not one of the categories above (BACEN catch-all)

Time limits and deadlines

An infraction report follows strict regulatory deadlines:

Rule	Time limit
Transaction age limit	A report applies only to a transaction from the last 80 days
Analysis period	The counterparty has 7 calendar days to analyze and close the report
Refund request window	After an AGREED close, the reporter has 72 hours to create a refund request
Fund release	The blocked funds release when no refund request arrives within 72 hours

Infraction report lifecycle

An infraction report moves through these statuses:

Status	Description
OPEN	The report is filed and waits for analysis
ACKNOWLEDGED	The counterparty received and acknowledged the report
CLOSED	Analysis is complete and the report closes with an AGREED or DISAGREED result
CANCELLED	The reporter cancelled the report (from OPEN, ACKNOWLEDGED, or CLOSED status)

Closure and automatic fraud markers

When an infraction report closes with an AGREED result, the system creates a fraud marker for the affected individual automatically. This links the investigation to the anti-fraud system and tracks the flagged individual across the Pix ecosystem.

Available operations

• List: Query infraction reports with filters (status, situation type, linked funds recovery)
• Retrieve: Get the full details of one report
• Acknowledge: Acknowledge an OPEN report as the receiving counterparty
• Close: Submit the analysis with an AGREED or DISAGREED result
• Cancel: Cancel a report you filed (from OPEN, ACKNOWLEDGED, or CLOSED status)

Refund requests

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A refund request returns funds to the original sender after the participant confirms an infraction. It is the financial execution step of the MED process.

When to create a refund request

You create a refund request after the participant investigates and closes an infraction report. The rules depend on the reason:

Reason	Prerequisite
FRAUD	Needs a closed infraction report with an AGREED result. Create it within 72 hours of closure.
OPERATIONAL_FLAW	Needs no prior infraction report. Use it for a processing error or operational issue.

Time limits

Rule	Time limit
Transaction age	Create a refund request within 80 days of the original transaction (30 days if the original was itself a refund)
Post-infraction window	For the FRAUD reason, create it within 72 hours after the infraction closes
Monitoring period	For a partial refund or an insufficient-balance rejection, monitor the account and process more partial refunds as funds arrive

Analysis outcomes

When the counterparty analyzes a refund request, one of three outcomes applies:

Result	Description
TOTALLY_ACCEPTED	The full refund is approved and executed
PARTIALLY_ACCEPTED	A partial refund is approved, for example on insufficient funds
REJECTED	The refund is denied, with a rejection reason

A rejection carries one of these reasons: NO_BALANCE (insufficient funds), ACCOUNT_CLOSURE (a closed account), INVALID_REQUEST (a request that does not meet the rules), PARTICIPANT_EXCLUSION (the participant is excluded from settlement), or OTHER.

Available operations

• Create: Open a new refund request for a transaction
• List: Query refund requests with filters (status, refund reason, transaction, infraction report, participant)
• Retrieve: Get the full details of one request
• Close: Submit the closure decision with the analysis result
• Cancel: Cancel a refund request before processing (only from OPEN status)

Fraud markers

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A fraud marker flags an individual (by CPF/CNPJ) and a Pix key as linked to fraudulent activity. It is a central part of the Pix anti-fraud ecosystem, managed through BACEN’s DICT.

How fraud markers are created

A fraud marker starts in one of two ways:

1. Directly: A participant registers a fraud marker for a tax ID and a Pix key through the API
2. Automatically: When an infraction report closes with an AGREED result, the system creates a fraud marker for the affected individual

Fraud classification types

When an infraction report closes with AGREED, the reporter records a fraud classification:

Type	Description
APPLICATION_FRAUD	Identity theft or a false application
MULE_ACCOUNT	An account used to receive and move illicit funds
SCAMMER_ACCOUNT	An account used to scam victims
OTHER	A fraud type outside the specific categories

Fraud marker lifecycle

Status	Description
ACTIVE	The marker is active and visible in anti-fraud queries across the ecosystem
INACTIVE	The marker is cancelled and no longer active

Only the participant that created a fraud marker can cancel it. A cancelled marker stays inactive. Create a new marker if you need one again.

Available operations

• Create: Register a new fraud marker for a tax ID and a Pix key
• List: Query fraud markers
• Retrieve: Get the full details of one marker
• Cancel: Cancel a marker (only from ACTIVE status)

Statistics and risk assessment

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The MED statistics capabilities return aggregated anti-fraud and transaction data for risk assessment. This data helps an institution evaluate the risk of a person or a Pix key before it processes a transaction.

What statistics are available

Statistics come at two levels:

Person statistics (by CPF/CNPJ)

This level aggregates data for one individual or entity. The provider returns:

• Settlement history: The count of settled transactions over each period
• Fraud markers: Counts by fraud type
• Total fraud amounts: The monetary impact of fraud-related transactions
• Infraction reports: Open and rejected report counts
• Registered accounts: The count of accounts with Pix keys linked to this person

Key statistics (by Pix key)

This level covers one Pix key, plus the current owner’s statistics:

• Key-level data: Settlement history, fraud markers, infraction reports, and account registrations for the key
• Owner-level data: The full person statistics for the key’s current owner

Time periods

The provider aggregates statistics over three time windows:

Period	Code	Description
90 days	d90	Recent activity, most relevant for active fraud detection
12 months	m12	Medium-term view of behavior patterns
60 months	m60	Long-term historical context

Use cases

• Pre-transaction risk scoring: Query the destination key statistics before you approve a cash-out
• Onboarding verification: Check person statistics during account opening or key registration
• Monitoring dashboards: Track fraud-marker trends across your portfolio
• Regulatory compliance: Show due diligence in fraud prevention to auditors and regulators

Regulatory reference

This page gives a practical overview of Pix. For deeper technical, legal, and regulatory detail, always read the official documentation from the Central Bank of Brazil (BACEN). It covers rule changes, deadlines, and official requirements.

BACEN’s materials are the authoritative source for Pix rules. They hold the most complete and current specifications.