Card issuer declined payment:

When a charge is submitted to the issuer of your customer’s card, they have automated systems that determine whether or not to authorize it. These systems take various signals into account, such as your customer’s spending habits, account balance, and card information like the expiration date and CVC.

A Fraud Ruleset:

You may have created a Fraud Ruleset that prevented the transaction from being authorized. You can review your Rulesets by

  1. Select the main menu

  2. Select Administration

  3. Select Rulesets

Invalid API call

As you develop your integration, good testing should identify any potential bugs that would lead to invalid API calls. Consequently these failures should be rare in production. Invalid API calls typically don’t result in a payment appearing in your Dashboard. However, in a few edge cases you may see the payment appear.