# gateway.transaction_processing.invalid_account_number

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


**gateway**

The payment failed because the card or account number provided is invalid. This can occur due to typographical errors, incorrect card format, outdated saved card details, or a card that has been deactivated or replaced by the issuer.

## Recommended Customer Message

Your payment failed. Please double-check your card details and try again with the same or another card.

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

-   **Incorrect card number entry:** The card or account number entered by the customer is mistyped or incomplete.
-   **Invalid card format:** The card number does not conform to standard formats (e.g., missing digits, invalid Luhn check).
-   **Outdated stored card details:** The payment attempt was made using an expired or invalid saved card.
-   **Card no longer active:** The card has been deactivated or replaced by the issuer.

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

-   Inform the customer that their transaction failed due to an invalid card number.
-   Ask the customer to carefully review and re-enter their card or account number.
-   Ask the customer to try a different card or payment method if the issue persists.
-   Ensure that saved card data is up to date and formatted correctly.