Documentation Index
Fetch the complete documentation index at: https://support.wepayments.com.br/llms.txt
Use this file to discover all available pages before exploring further.
This guide covers WEpayments’ anti-fraud procedures for credit card transactions and MED (Special Return Mechanism) notifications from the Central Bank of Brazil.
Anti-fraud procedure (Credit Card)
The anti-fraud system is provided by our card processing partner and applies exclusively to Credit Card transactions.
How the anti-fraud system works
| Component | Description |
|---|
| Neural network | Interconnects multiple databases with dynamic indexing rules |
| Machine learning engine | Feeds risk analysis rule trees with behavioral pattern data |
| Rule trees | Map scenario-specific behavioral patterns to prevent false positives |
💡 The system is designed to ensure that false positives do not contaminate the analyses.
Critical field: Email address
The email address is one of the most important fields for fraud checking. Incorrect email addresses can trigger false fraud alerts.
| Best practice | Why |
|---|
| Always fill email correctly | Prevents unnecessary fraud flags |
| Use business emails when possible | More reliable than free email providers |
| Verify email format | Simple typos cause false positives |
Free and block lists
You can create custom lists to improve approval rates without compromising security:
| List type | Effect |
|---|
| Free list | Releases buyers according to their consumption profile |
| Block list | Blocks buyers based on risk profile |
💡 These lists help increase purchase approval rates for legitimate customers while maintaining security.
What is MED (Special Return Mechanism)?
The Special Return Mechanism (MED) is a Central Bank of Brazil process that allows banks to return funds from suspected fraudulent transactions. It is part of the PIX system’s security framework.
When MED is triggered
MED is triggered when:
| Scenario | Description |
|---|
| Fraud complaint | A customer reports an unauthorized transaction |
| Bank suspicion | A bank identifies potentially fraudulent activity |
| System detection | Automated fraud detection flags a transaction |
How WEpayments handles MED notifications
Step-by-step process
| Step | Description |
|---|
| 1. Notification received | WEpayments receives a MED notification from the Central Bank or a partner bank |
| 2. Transaction identified | The suspected transaction is located and frozen (if funds are still available) |
| 3. Account review | Your account may be temporarily restricted during the investigation |
| 4. Evidence requested | You may be asked to provide documentation supporting the legitimacy of the transaction |
| 5. Final decision | Funds are either returned to the originator (if fraud is confirmed) or released (if transaction is legitimate) |
Your responsibilities when a MED notification occurs
| Responsibility | Action required |
|---|
| Respond promptly | Answer compliance requests as quickly as possible |
| Provide evidence | Submit proof of service delivery or product shipment |
| Maintain records | Keep customer communications and transaction history |
| Cooperate fully | Work with our compliance team throughout the investigation |
MED outcomes
| Outcome | Description | Impact on your account |
|---|
| Fraud confirmed | Funds returned to the originator | Account may be restricted; potential penalties |
| Transaction legitimate | Funds released | Account returns to normal |
| Insufficient evidence | Case may be escalated | Additional documentation requested |
Preventing fraud and MED notifications
Best practices for merchants
| Practice | Why it helps |
|---|
| Verify customer identity | Reduces unauthorized transactions |
| Keep delivery proofs | Evidence if challenged |
| Monitor unusual patterns | Detect potential fraud early |
| Use anti-fraud tools | WEpayments’ fraud system helps screen transactions |
| Respond quickly to compliance | Prevents escalation |
For PIX transactions
| Prevention measure | Description |
|---|
| Validate PIX keys | Ensure keys are correct before processing |
| Confirm beneficiary identity | Verify you are paying the correct person |
| Keep transaction records | Maintain evidence of legitimate payments |
