Chargeback Ratio (VAMP)
Chargeback ratio is the share of transactions disputed by cardholders against total transaction count in a given month. Visa’s VAMP (Visa Acquirer Monitoring Program), replacing the older VDMP, tracks a blended fraud-and-dispute ratio and enforces a 1.5% early-warning threshold from 2026, tightening from the prior 0.9% dispute-only standard.
Crossing VAMP’s 1.5% threshold triggers acquirer review and possible fines that typically run from roughly 5,000 to 25,000 USD per month above-threshold, before any account closure. A business processing 500,000 EUR a month at a 2% ratio is already inside the enforcement band and should expect an acquirer call, not a warning email.
A rolling reserve is a percentage of each settlement an acquirer withholds for a set period, typically 90-180 days, to cover potential future chargebacks or refunds before releasing it back to the merchant.
MATCH (Mastercard’s Member Alert to Control High-risk Merchants), often called the Terminated Merchant File or TMF, is a shared database acquirers check before onboarding a new merchant.
An acquirer is the bank or financial institution that processes card payments on a merchant’s behalf, settling funds from the card networks into the merchant’s account.
A Payment Service Provider aggregates payment processing for merchants, typically holding the direct acquirer relationship itself and onboarding merchants under its own risk appetite, rather than each merchant applying to an acquirer directly.