This transaction has already been processed

The transaction with this signature was already included in a block and executed. Solana uses transaction signatures as unique identifiers and will not process the same one twice.

Common causes

1. Retry logic resending a successful transaction. Your retry loop sent the same signed transaction after it had already confirmed.
2. Multiple submission endpoints. You sent the same transaction to multiple RPC nodes, and more than one forwarded it successfully.

How to fix

This is not an error to fix — it means the transaction already succeeded.

1. Check the transaction status with getSignatureStatuses.
2. View the full transaction with getTransaction to confirm the result.
3. Update your retry logic to check for existing confirmation before resending.

FAQ

Did the transaction execute twice? No. Solana guarantees exactly-once execution. The second submission was rejected, not executed.

Should I worry about this error? No. It confirms that your transaction was processed. It is safe to treat this as a success if the original submission was intentional.

How can I avoid this error? Check getSignatureStatuses before retrying. If the status is confirmed or finalized, stop retrying.

Updated: 2026-10-19