VAMP Ratio

The VAMP Ratio is a count-based metric Visa uses to express a merchant's fraud and dispute activity relative to its legitimate card-not-present volume. Rather than weighing dollar amounts, it counts events: applicable fraud reports and disputes in the numerator, measured against settled card-not-present transactions in the denominator. That structure makes the ratio a compact indicator of how much problem activity a merchant is generating for every legitimate transaction it settles.

The formula is straightforward in shape, with the numerator grouped: VAMP Ratio = (Count of TC40 Fraud Reports + TC15 Disputes) ÷ Count of Settled TC05 Card-Not-Present Transactions. TC40 fraud reports and TC15 disputes are combined on top, and settled TC05 card-not-present transactions form the base. The applicable counts, the transactions that qualify, and the items that are excluded are all defined by current Visa program rules, so the ratio is subject to program rules and exclusions and should be interpreted against the version of the rules in force.

What makes the ratio easy to underestimate is its numerator. TC40 fraud reports are created when issuers report transactions as fraudulent, and many of those never become chargebacks. A merchant watching only its chargeback count therefore sees an incomplete picture and may believe it has more headroom than the ratio actually shows. Combining fraud reports and disputes is precisely what gives the VAMP Ratio its predictive value — and what makes reconciling both streams across channels essential.

Managing the ratio means working on both parts of the fraction. Reducing fraud at the source lowers TC40 reports; resolving eligible disputes early, before they escalate, holds down TC15 activity; and healthy, growing legitimate volume strengthens the denominator. Because the ratio feeds the Visa Acquirer Monitoring Program, keeping it well within program expectations is a direct way to protect the merchant account from remediation, reserves, or restricted processing terms.

The VAMP Ratio is the single number that most directly reflects whether a merchant's fraud and dispute activity is within Visa's expectations. Because it is count-based and blends fraud reports with disputes over settled card-not-present volume, it can move for reasons that a chargeback-only view would miss.

Watching the ratio continuously lets a merchant see pressure building — from rising fraud reports, rising disputes, or falling transaction volume — and act before it approaches a threshold that triggers monitoring or enforcement.

Merchants and acquirers use the ratio to gauge standing under the Visa Acquirer Monitoring Program. Both parts of the fraction matter: the numerator combines applicable TC40 fraud reports and TC15 disputes, while the denominator is settled TC05 card-not-present transactions, so the ratio reflects problem activity relative to legitimate volume.

Because the numerator includes fraud reports that may never become chargebacks, a merchant that tracks only chargebacks can understate its ratio. Reconciling TC40 and TC15 activity across channels produces a truer figure to manage against.

Display the formula in a compact treatment with the numerator grouped: VAMP Ratio = (Count of TC40 Fraud Reports + TC15 Disputes) ÷ Count of Settled TC05 Card-Not-Present Transactions. The calculation is subject to Visa program rules and exclusions, so applicable counts, eligible transactions, and excluded items are defined by current Visa rules and can change. The VAMP Ratio is a metric built from TC40 fraud reports and TC15 disputes; it is not the same as those individual records, and it is one input to the broader Visa Acquirer Monitoring Program rather than the program itself.