Fraud & risk · Glossary
Also called: Visa Acquirer Monitoring Program ratio
The VAMP ratio is the metric of the Visa Acquirer Monitoring Program: reported fraud (TC40) plus non-fraud disputes, divided by settled card-absent transactions. Merchants at or above the published Excessive threshold expose their acquirer to enforcement fees, which is why acquirers underwrite and monitor to it.
VAMP ratiosits inside the broader system of U.S. payment processing economics that determine a merchant’s effective rate. Most operators encounter this term on their merchant statement without understanding what it controls, which is how the four hidden fees covered by our methodology slip past unnoticed.