# Card Testing Fraud: How to Detect and Stop It in 2026

DevFeed: [Card Testing Fraud: How to Detect and Stop It in 2026](<https://devfeed.tech/articles/card-testing-fraud-how-to-detect-and-stop-it-in-2026-9716.md>)

Original publisher: [Read original article](<https://dodopayments.com/blogs/card-testing-fraud/>)

Author: Ayush Agarwal

Published: 2026-07-24T00:00:00Z

Content type: tutorial

Language: en

Sources: [Dodo Payments Blog](<https://devfeed.tech/sources/dodo-payments-blog.md>)

Topics: [Transactions](<https://devfeed.tech/topics/transactions.md>), [Bot](<https://devfeed.tech/topics/bot.md>), [dashboards](<https://devfeed.tech/topics/dashboards.md>), [data](<https://devfeed.tech/topics/data.md>), [Networks](<https://devfeed.tech/topics/networks.md>)

Tags: [bots](<https://devfeed.tech/tags/bots.md>), [checkout](<https://devfeed.tech/tags/checkout.md>), [cost](<https://devfeed.tech/tags/cost.md>), [fraud](<https://devfeed.tech/tags/fraud.md>), [guide](<https://devfeed.tech/tags/guide.md>), [networks](<https://devfeed.tech/tags/networks.md>), [payment](<https://devfeed.tech/tags/payment.md>), [payments](<https://devfeed.tech/tags/payments.md>), [security](<https://devfeed.tech/tags/security.md>), [transactions](<https://devfeed.tech/tags/transactions.md>), [web](<https://devfeed.tech/tags/web.md>)

## AI overview

This guide explains card testing fraud, in which attackers use automated, low-value or zero-value checkout attempts to identify valid stolen card numbers. It describes the attack pattern, its financial and operational costs, warning signs, and ways to block the activity without harming legitimate customers.

## Source excerpt

Card testing fraud floods your checkout with tiny transactions to validate stolen cards. Learn how to spot the signs, the costs it creates, and how to block it without hurting real customers.