VAMP Thresholds

by | Sep 18, 2025 | Chargebacks, High Risk, Rules

Risk dial illustrating risk as a sliding scale
Risk dial illustrating risk as a sliding scale

Risk management and mitigation to reduce exposure to chargebacks

Visa’s Acquirer Monitoring Program (VAMP) is a consolidated fraud and dispute monitoring program that uses a single “VAMP Ratio” (fraud and dispute counts divided by settled transactions) to assess merchant risk. Starting in April 2025, VAMP introduced new, stricter chargeback thresholds, with the “Excessive” merchant threshold set at 1.5% of transactions in 2025, dropping to 0.9% in 2026. The program also monitors for enumeration attacks, or card testing, flagging merchants with high enumeration ratios over 20%. Merchants must implement strong fraud prevention measures and reduce chargebacks and card testing to avoid penalties and account suspension under this new global framework.  

Key Aspects of VAMP
  • Consolidated Monitoring: 

    VAMP replaces several previous Visa programs into one unified framework for monitoring fraud and disputes. 

  • VAMP Ratio: 

    This is the core metric, calculated as the total count of fraud reports (TC40) and all disputed transactions (TC15), divided by the total number of settled transactions. 

  • New Thresholds:
    • 2025: The “Excessive” threshold for merchants is 1.5%. 
    • 2026: The “Excessive” threshold for merchants decreases to 0.9%. 
  • Enumeration Monitoring: 

    Visa tracks “enumeration attacks” (automated card testing) and flags merchants exceeding a 20% Enumeration Ratio on approved and declined transactions. 

How it Affects Merchants
  • Increased Risk: 

    Merchants with high VAMP ratios or enumeration rates risk being flagged as “High Risk” or “Excessive” and could face penalties. 

  • Penalties: 

    Merchants who exceed thresholds can face penalties, potentially including direct per-transaction fines or account shutdowns. 

  • Acquirer Responsibility: 

    Acquirers (banks) are also monitored under VAMP, and a merchant’s high VAMP ratio could lead to penalties for the acquirer, which may then impact the merchant. 

How to Stay Compliant
  • Implement Real-Time Fraud Detection: 

    Aacadia uses tools to identify and block suspicious transactions before they are processed. 

  • Utilize 3D Secure: 

    Employ 3D Secure (like Verified by Visa) to authenticate transactions and reduce fraud-related disputes. 

  • Monitor TC40 Reports: 

    Track the TC40 fraud reports issued by issuers to understand and address identified fraudulent transactions. 

  • Prevent Enumeration Attacks: 

    Aacadia  can help you protect against card testing by ensuring only legitimate transactions are processed. 

  • Proactive Chargeback Management: 

    Focus on reducing the number of chargebacks and fraud-related disputes across your merchant portfolio. 

Timeline 

  • April 2025: VAMP officially launched.
  • April – September 2025: An advisory period allowed acquirers and merchants to implement new processes.
  • October 2025: Enforcement and fines began for merchants exceeding the initial thresholds.
  • January 2026: Stricter VAMP thresholds go into effect.

Merchants that exceed card-network risk thresholds are often treated as high risk. Learn how Aacadia Payments handles high risk credit card processing.