Adapting to Visa's New VAMP Ratios

WHAT PSPS AND MERCHANTS NEED TO KNOW: PROACTIVE STRATEGIES TO CONTROL CHARGEBACK AND FRAUD BEFORE THEY BECOME PENALTIES.

Visa recently introduced its Visa Acquirer Monitoring Program (VAMP) – a single combined ratio for chargebacks and fraud to determine whether Payment Service Providers (PSPs) and merchants remain in good standing. VAMP replaces the earlier Visa Dispute Monitoring Program (VDMP) and Visa Fraud Monitoring Program (VFMP) with a single combined ratio.

Breaching VAMP ratios can result in higher fees, fines, or even loss of the ability to process Visa transactions. The program was launched on June 1, 2025, with official enforcement starting on October 1, 2025. Merchant thresholds tighten further on April 1, 2026.

VAMP shifts significant responsibility to the acquirers, which means acquirers will impose stricter control on merchants.

VAMP Metrics

New Core Metric: VAMP Ratio

• VAMP ratio = (FraudReports[TC40] + Disputes[TC15]) ÷ SettledTransactions(TC05)

• Scope: Card-not-present (CNP) transactions.

VAMP Ratio Thresholds

• PSPs / Acquirers

  • Above Standard: ≥ 0.50% (50 bps)

  • Excessive: ≥ 0.70% (70 bps)

• Merchants

  • AP, Canada, EU, U.S.: ≥ 220 bps

    • Drops to 150 bps on Apr 1, 2026

  • Other regions: ≥ 130 bps.

  • Volume Floors: e.g., 300+ dispute count in AP/Canada/EU/U.S.

Enumeration (Card Testing) Metrics Inside VAMP

• Enumeration Ratio: Enumerated auths ÷ all auths ≥ 2000 bps.

• Enumeration Count: ≥ 300,000 enumerated auths.

Implications of breach for PSPs or their merchants

• Financial: Penalties, increased fees, and higher reserves.

• Operational: Extra audits, stricter controls and mandated remediation plans.

• Reputational: Loss of credibility with sponsor banks.

• Strategic: Risk of merchants losing Visa acceptance overnight.

Key point: Even false or fraudulent chargebacks count toward the ratio once filed. Winning a dispute does not remove it from the calculation.

Practical Steps to Protect Against VAMP Breaches

For PSPs and Acquirers

• Real-time Ratio Monitoring

  • Track fraud (TC40) and dispute (TC15) volumes. Don’t wait for Visa’s monthly reporting lag (computed at the end of the month).

• Merchant Segmentation

  • Identify high-risk merchants and verticals.

  • Apply targeted monitoring to identify issues before they inflate ratios portfolio-wide.

• Pre-Dispute Resolution Tools

  • Use Visa CE 3.0, Rapid Dispute Resolution, and other mechanisms that prevent a dispute from becoming a TC15. where appropriate.

• Enumeration Controls

  • Deploy velocity checks, device fingerprinting, and BIN-level monitoring to catch card-testing attacks early.

  • Use automation to detect and block enumeration spikes.

For Merchants

• Fraud Prevention at Checkout

  • Use device fingerprinting and behavioral risk scoring for transactions.

  • Use 3DS2 for higher-risk transactions.

  • Balance security with conversion. Too many declines can also trigger disputes.

• Enumeration detection & controls

• Monitor Metrics

  • Track internal chargeback and fraud ratios to spot risks early.

• Dispute Avoidance Practices

  • Respond quickly to pre-dispute notifications to prevent escalation into TC15.

  • Disputes remain in the ratio even if you win them. Prioritize prevention and early resolution rather than relying on representment.

Key Takeaways

• The VAMP program shifts compliance towards prevention rather than reactive dispute management. Do not wait until the end of the reporting cycle to identify problems.

  

  VAMP thresholds at a glance

• Both PSPs and merchants must strengthen fraud defenses, dispute prevention strategies, and real-time visibility.

• Enumeration risk: Card-testing spikes can distort ratios in a matter of hours, potentially for the entire PSP portfolio. Establish defenses that can react rapidly.

Idenza Solution

Idenza helps PSPs and fintechs stay ahead of VAMP thresholds through a smart, proactive approach:

• Real-time monitoring of critical ratios

• Enumeration detection: block card-testing attacks before they inflate VAMP ratios.

• Flag high risk merchants or users that could push ratios into amber or red.

• Automation: lower the cost of manual detection and triage.

Business Impact

• Prevent surprises.

• Reduce penalties and fines.

• Protect merchant / PSP credibility with Visa and sponsor banks.

Contact us to learn more about how Idenza can help you stay compliant under the new VAMP rules.