# gateway.transaction_authorization.auth_code_invalid

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


**gateway**

The transaction failed because the authorization code is missing or invalid. This happens when the transaction request does not include a valid authorization code, the system failed to supply it properly, the code has expired, or the issuer did not generate one.

## Recommended Customer Message

We couldn't process your transaction because required payment information is missing. Please try again, and if the issue continues, contact your bank for help.

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

-   **Missing or invalid authorization code:** The transaction request did not include a valid authorization code required for processing.
-   **Incorrect integration or configuration:** Your system failed to supply the authorization code properly during the transaction request.
-   **Authorization code expired or invalidated:** The provided code is no longer valid due to expiry or a prior reversal.
-   **No code generated by issuer:** The initial transaction failed to receive an authorization code from the issuer, leading to incomplete processing.

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

-   Verify that the merchant payment system correctly captures and submits the authorization code during the transaction process.
-   Ensure transaction flows are configured to handle and store authorization codes properly for subsequent processing steps.
-   If the issue persists, contact the payment gateway for further assistance.
-   Retry the transaction only after confirming that the authorization code is correctly generated and included in the request.