If your processor recently mentioned your "VAMP ratio," it was not making conversation. Visa's monitoring program now combines fraud and disputes into a single number, and in April 2026 the line a US merchant must stay under got lower. For high-risk merchants already working with thin margins of error, that change matters.
Here is how Visa VAMP works, what changed in 2026, and what you can do before your acquirer has to call you.
What VAMP replaced, and why Visa merged the programs
For years Visa ran two separate programs. The Visa Dispute Monitoring Program tracked chargebacks, and the Visa Fraud Monitoring Program tracked fraud. A merchant could look fine in one and be in trouble in the other.
The Visa Acquirer Monitoring Program, known as VAMP, replaced both in 2025. Visa began applying the new ratio on June 1, 2025, ran an advisory period through September 30, 2025, and began enforcement after that.
The name tells you the design. VAMP is aimed at acquirers, the banks that sponsor merchant accounts. Visa measures each acquirer's portfolio and each merchant within it, and it holds the acquirer accountable for the merchants it brings onto the network. That pressure flows straight down to you.
Under VAMP, your fraud and your disputes are one problem with one number, and your bank answers for that number before you ever hear about it.
How the VAMP ratio is calculated
Visa's published formula is:
VAMP ratio = (fraud reports + disputes) / settled transactions
Each piece has a specific source:
- Fraud reports (TC40): fraud cases that card issuers report to Visa on your transactions.
- Disputes (TC15): chargebacks filed against your transactions.
- Settled transactions (TC05): your completed sales.
The ratio counts card-not-present transactions only, including both domestic and cross-border volume. In-store card-present sales do not enter the calculation.
The double-count trap
A single fraudulent order can generate both a TC40 fraud report from the issuer and a TC15 dispute from the cardholder. Both count in the numerator. One bad order can therefore weigh twice as heavily as many merchants expect.
This is also why VAMP punishes slow fraud detection. By the time a stolen card produces a chargeback, the issuer may already have reported it as fraud.
The thresholds, including the April 2026 change
Visa sets a merchant-level "Excessive" threshold. A merchant is identified when it crosses both a ratio and a minimum count of fraud reports plus disputes in a month.
When VAMP launched, the Excessive merchant threshold for the US, Canada, Europe, and Asia Pacific was a ratio of 2.2% (220 basis points) with at least 1,500 combined fraud reports and disputes in the month. Visa's own fact sheet stated that the threshold would drop to 1.5% (150 basis points) in those regions on April 1, 2026, and that is the level that now applies to US merchants.
Latin America started at 1.5%. The Central Europe, Middle East and Africa region kept 2.2%, with a different minimum based on count and dollar amount.
Acquirers are held to a stricter line
Visa also measures each acquirer's whole portfolio. Its fact sheet lists an "Above Standard" level at 0.5% and an "Excessive" level at 0.7% for acquirers. Those numbers are far below the merchant threshold, which explains why many acquirers set internal limits well under 1.5% and step in early.
In practice, the threshold that matters most to you may be the one in your merchant agreement, not the one in Visa's rules. Ask your provider what internal ratio triggers a review.
What happens if you cross it
Merchants identified as Excessive face per-item fees on fraud and dispute counts, which Visa assesses to the acquirer and which acquirers typically pass on. Continued problems can lead to remediation plans, reserves, or account closure. Visa does not publish every enforcement detail publicly, and acquirers set their own merchant terms, so ask your provider exactly what your agreement says.
Enumeration: card testing now has its own measure
VAMP also targets card testing, which Visa calls enumeration. This is when fraudsters push large volumes of card numbers through a checkout to find the valid ones.
Visa measures an enumeration ratio, the share of a merchant's authorization attempts that are identified as enumeration. A merchant is flagged when that ratio reaches 20% or more and the count of enumerated transactions is at least 300,000 in a month.
Those numbers sound large, but automated attacks can produce them quickly. A merchant can be pulled into monitoring for enumeration even if almost none of the testing turned into real fraud losses. Bot defenses and velocity limits are no longer optional extras.
A worked example of the VAMP ratio
Numbers make this concrete. The figures below are illustrative, not drawn from any real merchant.
Imagine a US online merchant that settles 120,000 card-not-present Visa transactions in a month. During that month, issuers file 900 fraud reports and cardholders file 1,100 disputes against the merchant's transactions.
- Fraud reports plus disputes: 900 + 1,100 = 2,000
- VAMP ratio: 2,000 / 120,000 = 1.67%
Under the original 2.2% threshold, this merchant would have been below the Excessive line. Under the 1.5% threshold that applies from April 2026, with more than 1,500 combined fraud reports and disputes, it would be over. Nothing about the business changed. The line moved.
Notice also how the double count works. If 400 of those disputes came from the same stolen-card orders that produced fraud reports, those 400 orders contributed 800 items to the numerator. Stopping them before settlement would have pulled the ratio well under the line.
Where Mastercard fits: ECM and EFM
Mastercard runs its own monitoring programs, and high-risk merchants usually need to watch both networks.
- Excessive Chargeback Merchant (ECM): generally triggered when a merchant has at least 100 chargebacks in a month and a chargeback ratio of 1.5% or higher. Mastercard calculates the ratio using the current month's chargebacks against the prior month's transactions. A higher tier applies at 300 chargebacks and 3%.
- Excessive Fraud Merchant (EFM): focuses on fraud in e-commerce transactions, with criteria that include a fraud-to-sales ratio of 0.5% or more, a minimum fraud dollar amount, a minimum transaction count, and low use of 3-D Secure authentication.
The structures differ from VAMP, but the lesson is the same. Fraud and disputes feed network monitoring, and both networks expect acquirers to act.
What high-risk merchants should do now
Know your number every month
Do not wait for your processor to report your ratio. Track card-not-present fraud reports, disputes, and settled transactions yourself, by Visa and Mastercard separately. Watch trends, not just month-end totals.
Stop fraud before it settles
Every stolen-card order you block avoids a likely TC40 and a possible TC15. Risk scoring, address and CVV checks, device data, and selective 3-D Secure all help. Our page on fraud screening for high-risk merchants covers the core tools.
Lock down card testing
Rate-limit attempts by IP, device, and card. Challenge suspicious traffic before it reaches authorization. Alert on decline spikes in real time so you can respond within minutes.
Resolve disputes before they become disputes
Pre-dispute tools can let you refund a contested transaction before it becomes a chargeback. Tools such as Visa's Rapid Dispute Resolution can keep a case from becoming a TC15 dispute, but they generally do not remove a fraud report the issuer has already filed. Ask your provider how each alert or resolution tool affects your VAMP count.
Fix the causes of friendly fraud
Clear billing descriptors, visible cancellation paths, renewal reminders, and responsive support reduce disputes from customers who simply did not recognize a charge. Our chargeback prevention guide walks through the operational fixes.
Spread risk thoughtfully
Some merchants with several distinct brands or product lines run separate merchant accounts for each, so one product's issues do not drag down the whole business. This only works when every account is accurately described to the acquirer. Splitting volume to hide a ratio is a fast route to closure and the MATCH list.
Why this matters more for high-risk businesses
Mainstream processors already tend to treat high-risk categories cautiously. Under a lower Visa threshold, an account that was borderline in 2025 can become a problem in 2026 with no change in how you operate. That is often how merchants end up facing sudden reserves or closures, which we cover in how to avoid account holds.
The answer is not to hope your ratio stays low. It is to run the account as if VAMP is reading it every month, because it is. Pairing your merchant account with chargeback alerts and dispute management gives you room to act before a ratio turns into a remediation plan.
Check your VAMP exposure before your bank does
Pull your last three months of Visa card-not-present fraud reports and disputes, divide by settled transactions, and compare the result with 1.5% and with whatever internal limit your processor uses. If you are close, you have time to act now. If you are well under, document what you are doing right so you can show it in your next review.
If you want an account set up with protection against monitoring-program fallout, start your application with Karma Card Payments and we will review your current ratios with you.
Sources and timing
Last reviewed October 5, 2026. Network rules and legal requirements can change; confirm the rules that apply to your account and products.