11607

Returns from the DoExpressCheckoutPayment API.

• A transaction has already been completed for this token. The request was previously processed, and the results were returned in the initial response.
• To prevent duplicate charges, PayPal marks the request as a duplicate and does not process it again. The buyer is not charged twice. Along with the error code, PayPal returns the result parameters of the original request for reference.

There is no impact on the original transaction. This is a decline on a second attempt at processing the same PayPal transaction.

• No action required for prior payments: If the request pertains to a payment that was already processed, no further action is required.
• Submit new transaction requests correctly: If this is a new transaction request, submit it with a different MSGSUBID or INVOICE_ID to avoid being flagged as a duplicate.
• Subscribe to Instant Payment Notifications (IPNs) or webhooks: Subscribe to IPNs or webhooks to keep your system updated with PayPal's latest payment status, even if the initial API response is missed. This prevents duplicate transaction requests and ensures your system stays synchronized with PayPal.

The NVP/SOAP API integration method is deprecated. You can find more information about our latest integrations from the following resources:

• REST APIs
• PayPal Checkout
• PayPal Developer homepage

• Express checkout token
• NVP/SOAP integration
• NVP/SOAP error codes