Insights provided by Scott Stone, Chief Strategy Officer

Visa’s new Acquirer Monitoring Program (VAMP) officially went live on April 1, 2025. After six months of advisory monitoring, formal enforcement begins October 1, 2025. With thresholds finalized, new fraud/dispute counting rules clarified, and regional nuances now confirmed, it’s critical for merchants to understand how VAMP works and what steps to take before penalties start.

This updated guide summarizes the key thresholds, timelines, and best practices every merchant should know, based on Visa’s latest announcements and our recent discussions at the 2025 MAG Payments Conference.

What is VAMP?

VAMP replaces Visa’s legacy acquirer and merchant monitoring programs with a combined fraud and dispute ratio framework. It is designed to hold acquirers accountable for their portfolios while also forcing merchants to reduce fraud, chargebacks, and enumeration attacks.

Key Dates to Know

• April 1, 2025 – VAMP launch and start of advisory period.

• June 1, 2025 – New thresholds and minimum event counts take effect.

• September 30, 2025 – Advisory period ends.

• October 1, 2025 – Enforcement begins; Visa penalties possible.

• April 1, 2026 – Stricter merchant thresholds (1.5%) go live in U.S., Canada, and EU.

Updated Thresholds (June 1, 2025)

For Merchants

• Excessive: 2.2% combined fraud + dispute ratio (phasing down to 1.5% in 2026 for many regions)

• Minimum event count: 1,500 disputes + fraud reports per month

For Acquirers

• Above Standard: 0.50%

• Excessive: 0.70%

Enumeration

• Enumeration ratio threshold: ~20%

• Enumeration count threshold: ~300,000 authorizations (varies by region)

How Events Are Counted

TC40 Fraud Reports (Issuer-confirmed fraud)

• Always count toward VAMP ratios.

• May only be removed with Compelling Evidence 3.0 or other Visa-approved evidence.

• Challenge: Merchants rarely receive TC40 data directly. You may need to request reports from your acquirer or Verifi.

TC15 Disputes (Fraud + Non-Fraud)

• Count toward ratios unless resolved early through Verifi RDR, Verifi CDRN, or Ethoca Alerts.

• Early resolution via these networks can prevent escalation into chargebacks, reducing your Vamp count.

Double Counting Risk

• A single fraudulent transaction may generate both a TC40 (fraud report) and a TC15 (dispute). In some cases, both count.

Obtaining and Proxying TC40 Data

Because TC40 data is often difficult to access directly:

Best Source – Obtain the TC40 report directly from Verifi or your acquirer. This is the most accurate method.

Alternative Proxy – If direct access is unavailable, you can proxy TC40 counts by:

• Counting all fraud disputes received and resolved through Verifi RDR, Verifi CDRN, and Ethoca Alerts.
• Supplementing with fraud chargeback data from your acquirer.

Practical Approach – Proxy or estimate TC40 using these inputs, then track your VAMP Count and VAMP Ratio as you would other key payment metrics.

Tracking and Monitoring VAMP Metrics

To stay ahead of enforcement:

• Track Vamp Count & Vamp Ratio – Monitor these just like you would approval rates, decline rates, or chargeback ratios.

• Group by Acquirer and Descriptor – Since VAMP applies at the acquirer level, analyzing by acquiring relationship and merchant descriptor reveals where risk is concentrated.

• Monitor Trends – Look at monthly and rolling 3-month averages.

• Enable Alerts or Reviews – Set thresholds internally (e.g., 1.5% warning alert, 2.0% escalation) to catch issues before Visa or your acquirer does.

• Integrate Into Reporting – Fold these ratios into your BI dashboards and review them weekly.

Regional Variations

Thresholds and timelines differ by region:

• U.S./Canada/EU: merchant threshold drops to 1.5% on April 1, 2026.

• Other regions: may remain at 2.2% until later phases.

• Enumeration triggers also vary based on local issuer/acquirer volumes.

What Happens If You Exceed Thresholds?

• Advisory Period (until Sept 30, 2025): No direct penalties from Visa, but acquirers may already take action (higher reserves, stricter terms).

• After Oct 1, 2025: Merchants and acquirers face Visa fees and compliance programs if ratios stay high.

Preparing for Enforcement: Merchant Checklist

1. Audit your ratios – Review fraud + dispute ratios from the past six months against the 2.2% and 1,500-event thresholds.
2. Strengthen fraud controls – Adopt 3DS 2.0, machine-learning fraud tools, and velocity checks to prevent fraud spikes.
3. Use Verifi RDR, Verifi CDRN, and Ethoca Alerts – Resolve disputes before they escalate into chargebacks.
4. Obtain or proxy TC40 data – Request reports from Verifi or your acquirer. If not possible, proxy TC40 counts with resolved fraud disputes across Verifi/Ethoca channels.
5. Track VAMP Count & Ratio – Treat them as core payment KPIs, grouped by acquirer and descriptor.
6. Deploy Compelling Evidence 3.0 – Ensure your evidence collection processes are aligned.
7. Monitor enumeration – Implement bot detection and card-testing prevention. Proxy enumeration with deep authorization decline analytics if issuer reporting isn’t available.
8. Engage your acquirer – Confirm how they are measuring your ratios and whether they have VAMP reporting dashboards.
9. Educate internal teams – Customer service, fulfillment, and finance must all align on reducing disputes and fraud.

How Harmonize Can Help

The Optimized Payments Harmonize Platform now includes VAMP Count and VAMP Ratio as built-in KPIs.

• Each metric can trigger real-time alerts and be tracked across regions, issuers, acquirers, and descriptors.

• Dashboards enable merchants to monitor trends, identify emerging risks, and drill into root causes before thresholds are exceeded.

• Enumeration activity can also be proxied with deep authorization decline analytics, helping merchants detect bot attacks or card testing before ratios spiral.

Contact us to learn how Harmonize can simplify VAMP compliance and help protect your payment performance.

Final Thoughts

With enforcement beginning October 1, merchants have a narrow window to bring fraud and dispute ratios under control. The shift from advisory to enforcement will mark a new era of accountability, not just for acquirers but also for merchants who fall into “Excessive” thresholds.

Success will require accurate monitoring of TC40 and TC15 events, effective use of Verifi and Ethoca tools, and proactive tracking of VAMP metrics as part of your payment operations. Platforms like Harmonize can turn these complex compliance demands into actionable insights, ensuring you stay ahead of enforcement and safeguard long-term payment performance.