# gateway.merchant_account.authentication_failure

> For the complete machine-readable documentation index, see [llms.txt](https://apidocs.chargebee.com/llms.txt).


**gateway**

The gateway authentication failed. This happens when authentication credentials are invalid or expired, API access has been revoked, integration settings are incorrect, or the gateway requires updated authentication protocols.

## Recommended Customer Message

We are unable to process your payment due to a merchant authentication failure. Please try again later or use a different payment method. Thank you for your understanding.

## Root Cause[](#root-cause)

-   **Invalid or expired credentials:** Your gateway credentials are incorrect or have expired.
-   **Revoked API access:** The payment gateway has revoked your authentication tokens, preventing transaction processing.
-   **Incorrect integration settings:** The authentication details configured in Chargebee or your system do not match those expected by the payment gateway.
-   **Gateway security updates:** The payment gateway requires updated authentication protocols or methods that have not been implemented.

## Troubleshooting and Solutions[](#troubleshooting-and-solutions)

-   Verify and update the merchant's authentication credentials (API keys, tokens, or login details) in the payment gateway configuration.
-   If credentials have expired or been revoked, generate new ones and update them immediately.
-   Contact the payment gateway support team to resolve any outstanding authentication issues or account restrictions.
-   Retry the transaction after successfully updating and validating authentication credentials.
-   Set up proactive monitoring to receive alerts when authentication credentials are near expiration to prevent future failures.