Velocity check
Auth & security
A fraud-screening rule that limits the number, amount, or frequency of transactions from a single source over a time window, single card, single IP, single device. Velocity checks block card-testing attacks, account-takeover bursts, and credential-stuffing flows that would otherwise drive fraud-chargeback rates upward.
In practice.
Velocity checks cap repetition: how many attempts a card, IP, device or account can make in a window. They are the first line against card testing, which otherwise fills your account with small authorizations and fraud reports. Sensible velocity rules at the gateway are standard in every high-risk setup.
Related terms: Fraud rate · TC40
Auth & security