Understanding Visa's New Dispute Rules

On April 1, 2025, Visa introduced a new compliance framework called the Visa Acquirer Monitoring Program (VAMP). In this article, we’ll walk you through what VAMP is, what has changed, and what you need to do to stay compliant and avoid penalties.

The Visa Acquirer Monitoring Program (VAMP) is Visa’s updated program for monitoring merchants and payment processors for excessive chargebacks, fraud, and enumeration activity (i.e., fraudulent card testing attacks) on all transactions done with Visa-issued cards.

This new program replaces the previous Visa Dispute Monitoring Program (VDMP) and Visa Fraud Monitoring Program (VFMP) and introduces stricter rules that affect both acquirers, processors, and merchants.

Visa has lowered the acceptable dispute ratios across the board:

📌 This means merchants must keep their dispute ratios below 0.5% starting October 1, 2025, or risk penalties.

The formula below shows how to calculate your ratio under VAMP:

{(The number of Visa disputes in a given month) ➗ (The number of Visa transactions in that same month)} ✖️ 100.

Visa now includes fraud claims in dispute monitoring. This is a big change, as previously, chargebacks and fraud were handled separately. Under VAMP, both will count toward your dispute ratio.

That means if someone raises a fraud claim on your business, it impacts your overall dispute ratio in the same way that a chargeback would.

Visa will now actively monitor enumeration attacks — attempts by fraudsters to test stolen card data on your platform by guessing combinations of card numbers, expiry dates, CVVs, or OTPs.

If your business processes more than 300,000 international transactions monthly and records an enumeration ratio of 20% or higher, you may be flagged.

Enumeration ratio formula:

Number of declined authorization attempts / Total number of authorization attempts * 100

Where:

• Declined authorization attempts = The number of transaction attempts that were declined, especially those flagged due to invalid card details, wrong CVV, expiry date, etc.

• Total authorization attempts = All transaction attempts (successful + declined) within the monitoring period. </aside>

From October 1, 2025, businesses that exceed the allowed thresholds may be subject to $10 per chargeback or fraud claim.

Please note that these fees will be passed to your position, so it’s in everyone’s best interest to stay compliant.

We’re working proactively to support you during this transition period. Here are some best practices for you:

1. Monitor your dispute volumes: This is the most important step. You should monitor your dispute volumes (both chargebacks and fraud claims) very closely to ensure that you’re not crossing the acceptable dispute ratio. For guidance on how to calculate your ratios, please refer to this article. At Paystack, we proactively monitor your dispute ratio using a stricter internal ratio to help you stay well below Visa’s limits, reducing the risk of warnings and fines.

2. Resolve customer issues early: Many disputes are preventable. Offer responsive customer support and proactively issue refunds when they’re due, to avoid unnecessary chargebacks.

3. Use clear billing descriptors: Confusing or vague billing names can cause customers to dispute legitimate transactions. Ensure your business name is easily recognizable on customer bank statements.

4. Keep an eye out for suspicious transaction attempts: Monitor your transaction activity for unusual or suspicious patterns that could indicate fraud, such as repeated failed attempts from the same customer, customers using weird-looking email addresses, or the same customer attempting several payments with different cards.

5. Provide thorough documentation for disputes: Always respond quickly with:

   • Proof of delivery or service fulfilment on a document that clearly shows your business name

   • Transaction records

   • Clear refund and cancellation policies that are presented to customers before payment

We’ve also put together industry-specific dispute guides to help you manage disputes more effectively.

The VAMP changes affect all of us — merchants, processors, and acquirers alike. At Paystack, we’re committed to helping you stay compliant and protect your business from chargebacks, fraud, and enumeration threats.

If you notice any suspicious transaction attempts from your customers or you have any questions at all, please don’t hesitate to reach out to our support team - support@paystack.com. Let’s work together to keep your business compliant.

• https://corporate.visa.com/en/sites/visa-perspectives/security-trust/introducing-visa-acquirer-monitoring-program.html

• https://www.chargebackstop.com/blog/visa-acquirer-monitoring-program

• https://usa.visa.com/dam/VCOM/download/about-visa/visa-rules-public.pdf

• https://www.rapyd.net/blog/visa-vamp-program/