Root Cause

• Incorrect card information: The card number, expiration date, or CVV is invalid.

• Invalid billing information: Required fields like billing address, postal code, or country are missing or incorrectly formatted.

• Unsupported payment method parameters: Parameters provided do not match the gateway's expected formats or supported payment methods.

• Incorrect API payload: The merchant system sent an invalid request to the payment gateway.

Troubleshooting and Solutions

• Inform the customer that their payment failed due to invalid payment details.

• Ask the customer to:

  • Verify and re-enter their payment information carefully.

  • Ensure all required fields, such as card number, CVV, expiration date, and billing address, are correct and valid.

• If the issue persists, recommend trying an alternative payment method.

• Refer to your gateway documentation to identify the specific invalid parameter.

• Ensure that the transaction payload sent to the gateway matches the expected formats to avoid repeated failures.