Transactions

Follow a Pix transaction end-to-end — initiation, authentication, SPI settlement, E2E ID, and instant credit — plus cash-in and cash-out patterns.

They represent the real-time movement of funds between accounts across all Pix participants, following the technical and regulatory standards of the Central Bank of Brazil (BACEN).

Pix transactions target speed, traceability, and interoperability. They keep consistent behavior regardless of the institution or front-end channel.

Key characteristics

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Pix transactions share a common foundation across all institutions:

Instant settlement

Funds typically settle within 10 seconds. SPI guarantees completion or handles the timeout transparently.

24/7 availability

Pix operates continuously — including weekends, holidays, and outside business hours.

Irrevocability

After a Pix completes and credits the receiver, only regulated flows can reverse it (Refunds, Devoluções, MED).

End-to-End ID (E2E)

Each Pix transaction receives a unique E2E identifier for auditability, reconciliation, and dispute handling.

Interoperability

Any Pix participant can send or receive Pix from any other, independent of institution, platform, or channel.

Configurable limits

Institutions must enforce regulatory and internal limits for security and fraud control.

How a Pix transaction works (End-to-End Flow)

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Figure 1. Pix Transaction Flow

A simplified cross-institution view of a Pix transaction follows:

1. Initiation

   The user starts a Pix transfer using one of the available addressing methods:

   • Pix key
   • QR Code (static or dynamic)
   • Manual bank details
   • Copy-and-paste EMV code

To learn more about Pix QR codes, please visit the QR Codes documentation.

1. Authentication & authorization

   The sending institution must authenticate the user with strong mechanisms (e.g., biometrics, 2FA, device trust).

   User consent is mandatory.

2. Validation & risk checks

   Before it sends anything to SPI, the institution must validate:

   • Account condition (active, not blocked, KYC verified)
   • Balance availability
   • Limits (transaction, daily, nightly, monthly)
   • Pix key validity (if applicable)
   • Risk assessments (anti-fraud indicators, velocity checks)

3. Settlement attempt (SPI)

   The institution submits the transfer to SPI (BACEN’s Instant Payment System), which:

   • Validates the message
   • Routes it to the receiving institution
   • Settles the transaction between institutions

4. Credit to receiver

   The receiving institution must credit the account immediately, even if:

   • It occurs outside business hours
   • Systems are under load
   • Amount is high (except for flagged anti-fraud cases)

5. Notifications & E2E generation

   • Both institutions receive the updated transaction status
   • The transaction receives a unique E2E ID
   • Webhooks or internal notifications update systems and users

Pix Transaction types

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Pix transactions fall into a few standardized categories governed by BACEN.

1. Cash-Out (Send Pix)

The payer sends funds to another account using a Pix key, QR code, or bank details.

Flow (summary):

1. User initiates transfer
2. Institution checks balance + limits + key
3. Institution sends the transaction to SPI
4. Receiver credits instantly
5. Both parties receive updates + E2E ID

Common scenarios:

• P2P transfers
• Merchant payments
• Bill splitting
• Marketplace split payments (when paired with Pix Cobrança)

2. Cash-In (Receive Pix)

The customer receives a Pix transfer from any other institution.

Flow (summary):

1. SPI notifies the receiving institution
2. The institution must credit the account immediately
3. The institution dispatches notifications for reconciliation
4. The institution records the transaction with an E2E ID

Common scenarios:

• Salary or corporate disbursements
• Merchant settlements
• Recurring customer payments

3. Refund (Devolução)

Regulated flow that allows institutions to return funds to the original sender.

The following can trigger a refund:

• Customer request
• Merchant refunds
• Duplicate payments
• Operational errors
• Fraud-related MED cases

A refund must:

• Use BACEN standard messaging
• Link to the original transaction
• Follow value and eligibility rules

4. Reversal (Chargeback / pacs.004)

Used in special regulated cases — often tied to MED or operational corrections.

Reversals follow strict BACEN rules and are not the same as merchant refunds.

Cash-out: two-phase transfer pattern

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The Lerian platform processes a Pix cash-out in a two-phase pattern that separates validation from fund movement. This design provides safety, compliance, and a better experience for both institutions and end users.

Why two phases

A Pix transfer involves multiple validations: key lookup, account verification, balance checks, limit enforcement, and anti-fraud evaluation. A single step that runs all of them creates risk — if something fails after partial execution, reversal becomes complex.

The two-phase pattern solves this by splitting the process:

1. Phase 1 — Initiate: Validate everything without moving funds
2. Phase 2 — Process: Execute the fund transfer using the validated data

This separation provides several advantages:

• Validation before commitment: All checks (balance, limits, key validity, anti-fraud) happen before any money moves
• User confirmation: The initiating application can display validated destination details to the user before they confirm the transfer
• Idempotency support: The application can retry each phase independently, with no duplicate transfers
• Compliance: The platform completes and records regulatory validations before fund movement begins

How it works

Phase 1: Initiate

The initiation phase creates a transfer record. It retrieves and validates the destination information. No funds move at this stage.

The platform supports three initiation types:

Type	Description	Input
MANUAL	Full destination account details provided directly	Bank, branch, account number, document, name
DICT	Destination resolved via Pix key lookup (DICT)	Pix key value (CPF, email, phone, EVP)
QR_CODE	Destination extracted from a QR code payload	BR Code (EMV) string

For DICT and QR_CODE initiations, the platform queries DICT to resolve the destination account. The initiation returns the account holder name, document, and institution, which the application can display for user confirmation.

The initiation returns a unique identifier and an expiration timestamp. The application uses this identifier in the next phase.

Phase 2: Process

The process phase takes the validated initiation and executes the actual fund movement:

• Verifies the initiation is still valid (not expired, not already processed)
• Debits the source account in the ledger
• Submits the payment to the Pix settlement infrastructure (SPI)
• Records the transfer with full traceability (end-to-end ID, timestamps, status)

After processing begins, the transfer follows the standard Pix settlement flow. You cannot cancel it. The regulated refund process is the only way to reverse it.

Lifecycle summary

Step	What happens	Funds moved?
Initiate	Validate destination, check key/QR, resolve account details	No
User confirms	Application displays details, user approves the transfer	No
Process	Debit source account, submit to SPI, credit destination	Yes
Complete	End-to-end ID assigned, both parties notified	—

Validation layers (Regulatory + Operational)

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Every Pix transaction goes through multiple validations before it reaches SPI:

1. Account checks

• Account active
• Not blocked
• KYC complete

2. Funds availability

• Sufficient balance
• Temporary holds released

3. Pix key validation

If the user pays with a key, the institution must fetch and confirm the recipient’s details from DICT.

4. Regulatory limits

• Per transaction
• Daily limit
• Nightly limit (mandatory)

5. Risk & fraud checks

Institutions may enforce:

• Velocity checks
• Device fingerprinting
• Behavioral analytics
• Known-fraud markers

6. Idempotency

Each Pix transfer must have a unique transaction ID.

This avoids duplicate transfers during retries.

Operational controls and safety

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Authentication requirements

Strong customer authentication is mandatory for all Pix send operations.

Notifications & Webhooks

After crediting, institutions must notify systems and users.

Webhooks allow real-time reconciliation.

Error handling

Common error categories include:

• Timeout
• Invalid key
• Insufficient funds
• Daily/nightly limit exceeded
• Suspicious transaction blocked

Auditability

Pix mandates full traceability:

• Logs
• Timestamps
• E2E ID
• Account metadata

Transaction limits (BACEN Rules)

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Pix transaction limits exist to reduce fraud risk, protect end users, and maintain operational safety across the instant payment ecosystem. BACEN defines minimum security standards, and institutions may add restrictions depending on their risk appetite.

Pix limits fall into two groups: mandatory regulatory limits and institution-defined limits.

1. Mandatory regulatory limits (BACEN)

Nighttime limit (Per-Transaction Cap)

Institutions must enforce a lower maximum limit between 20:00 and 06:00.

Regulatory requirements:

• Default maximum: R$ 1.000
• Institutions may set a lower default (e.g., R$500 or R$ 200)
• Customers may reduce this limit instantly
• Customers may increase this limit only after a minimum wait of 24 hours
• Customers may adjust the nighttime window (e.g., extend to 18h–08h)

This rule applies to:

• Pix transfer (cash-out)
• Pix QR Code payment
• Pix Saque/Troco
• Pix Cobrança payments initiated at night

Its purpose is to prevent fraud during higher-risk hours.

Allowance for Customer-Controlled limits

Institutions must offer customers the ability to configure their own limits, per:

• Transaction
• Day
• Nighttime maximum
• Other forms of risk-based segmentation

These changes must respect BACEN timing rules:

• Reductions → must take effect immediately
• Increases → can only take effect after a minimum of 24 hours (security delay)

Obligation to analyze requests for limit increase

Every institution must:

• Accept customer requests to increase limits
• Evaluate them through risk criteria
• Grant or deny based on fraud policy
• Apply increases only after the regulatory waiting period (24h+)

Saque/Troco limits (Cash-Out at merchants)

Pix Saque and Pix Troco have their own caps:

• Default: R$ 500 per transaction
• Institutions may voluntarily offer up to R$ 3.000 per transaction
• Customers may reduce this limit instantly
• Increases follow the same 24h rule

These limits do not affect normal transfers — they are specific to cash withdrawal modalities.

Credit obligations (independent of limits)

Even if a transfer exceeds the limits, after the receiver gets the credit:

• The transaction becomes irrevocable
• Only MED or refund flows can reverse it
• Institutions cannot “undo” a completed Pix on their own initiative

2. Institution-defined limits (Configurable)

Beyond mandatory rules, institutions may add their own controls, such as:

Per-Transaction limit

Maximum allowed amount for a single Pix operation.

Daily limit

Cap on total Pix amount per user per calendar day.

Monthly limit (optional)

Used mainly by corporate accounts or fintech risk models.

Risk-based segmentation

Institutions may offer:

• Stricter limits for new customers (ex.: first 7 days)
• Different limits for high-risk users or flagged accounts
• Dynamic limits adjusted by customer behavior

These internal controls must never conflict with BACEN requirements — only complement them.

3. Operational rules required by BACEN

Immediate limit reduction

Customers can lower their limits instantly.

Delayed limit increase

All increases must respect:

• 24 hours minimum before becoming effective
• Optional additional waiting period (institution’s choice)

Peak risk hours

Nighttime limits apply specifically to cash-out flows, as they represent the main vector for fraud losses.

Real-time enforcement

Institutions must check limits before they send a transaction to SPI.

The institution must reject a Pix that violates limits locally, before it reaches SPI.

4. Limit behavior in transaction lifecycle

During a Pix initiation

The sending institution must verify:

• Available balance
• Transaction limit
• Daily limit
• Nighttime limit
• Saque/Troco limit (if applicable)
• Fraud/velocity limits
• Customer-configured limits

If a transaction violates any rule, the institution must reject it with an appropriate code.

During retries

The institution must validate the limits again.

Idempotency prevents duplicate transfers but does not bypass limit checks.

During merchant flows

Dynamic QR Codes must also respect:

• Customer limits
• Time-of-day rules
• Saque/Troco caps

Even if the merchant sets an amount, the payer’s institution decides whether to approve.

5. Recommended customer communication

BACEN requires institutions to:

• Explain limits clearly
• Offer customer self-service to adjust limits
• Show pending increases and activation dates
• Notify customers in case of suspicious behavior

6. Summary table

Limit Type	Mandatory?	Default (BACEN)	Customer Controls	Activation Rules
Per-transaction	Optional	Institution-defined	Increase/reduce	Reduce = immediate / Increase = 24h
Daily	Optional	Institution-defined	Increase/reduce	Reduce = immediate / Increase = 24h
Nighttime (20h–06h)	Yes	Max R$ 1.000	Customer customizable	Increase = 24h delay
Saque/Troco	Yes	R$ 500 default	Customer configurable	Increase = 24h delay
Monthly	Optional	Institution-defined	Increase/reduce	Institution-defined

Regulatory reference

This page provides a practical overview of how Pix works. For deeper technical, legal, and regulatory details — and to stay up to date with rule changes, deadlines, and official requirements — always refer to the official documentation published by the Central Bank of Brazil (BACEN).

BACEN’s materials are the authoritative source for Pix regulations and contain the most complete and up-to-date specifications.