Payment gateway fraud is fraudulent activity that targets or flows through the payment gateway, the service that transmits transaction data between a store’s checkout and the payment networks. It includes stolen card transactions submitted through the gateway, card testing attacks that use the gateway to validate stolen credentials, and attempts to exploit gateway configuration weaknesses.
How Payment Gateway Fraud Works
The gateway sees enormous transaction volume, which makes it both a target and an instrument. Card testing fraud is the highest volume form: bad actors run thousands of small authorizations through a merchant’s gateway to sort live stolen cards from dead ones, leaving the merchant with authorization fees, decline spikes, and a damaged standing with processors. Straight payments fraud, purchases on stolen credentials, also transits the gateway, as do enumeration attacks that guess card numbers by brute force against loosely configured checkout endpoints.
How to Prevent Payment Gateway Fraud
Harden the checkout surface: require CVV and enable AVS, add bot protection and velocity limits on payment attempts, disable or protect any endpoint that accepts card data outside the normal flow, and monitor authorization decline rates for testing signatures. Then screen what the gateway can’t judge: the gateway moves data and applies basic checks, but deciding whether the person behind a technically valid transaction intends to pay requires dedicated fraud screening in front of it.
How Wyllo Helps
Wyllo sits where the gateway is blind. Pre-gateway screening stops bad transactions before they ever reach the gateway, protecting authorization rates and keeping card testing traffic out, while Wyllo Payment Fraud Protection evaluates identity, device, network, and behavioral signals on every order in real time.
Frequently Asked Questions
Doesn’t the payment gateway already screen for fraud?
Gateways apply basic checks like AVS and CVV verification and some offer rules engines, but their job is transmission, not judgment. Rich behavioral and identity screening is a different discipline, which is why dedicated fraud protection sits alongside or in front of the gateway.
Why does card testing hurt merchants even when the tests are declined?
Every attempt costs an authorization fee, decline spikes can trigger processor scrutiny, and any tests that slip through become chargebacks. High test volume can also degrade checkout performance for real shoppers.
