# gateway.transaction_processing.duplicate_transaction

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


**gateway**

The payment was rejected because a similar transaction has already been processed. This typically occurs when the same transaction is submitted multiple times, often due to duplicate clicks, delayed gateway updates, or reuse of transaction IDs.

## Recommended Customer Message

The collection has already been completed. Please check the transaction in your bank account or contact customer support for assistance.

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

-   **Duplicate transaction submissions:** The same transaction was processed multiple times, especially for first-time debit (FRST) transactions.
-   **Incorrect transaction IDs:** Submitting the same transaction ID more than once can lead to duplicate detection.
-   **Delayed gateway updates:** The gateway processes a transaction, but the status was not updated immediately, leading to resubmission attempts.

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

-   Ask the customer to check their bank account for the successful transaction.
-   Ask the customer to contact support if they need help identifying the transaction.
-   Verify transaction records in Chargebee and at the payment gateway to confirm that a payment was already processed.
-   Ensure that transaction IDs are unique and not reused for future attempts.
-   Avoid retrying until you confirm that no successful collection exists to prevent further duplication.
-   Try to collect payment using the Pay Now flow by creating a new transaction if there is no successful transaction recorded.