I am working with another party to debug my code. They use there amex card and get: The PayPal API has returned an error! Ack: Failure Correlation ID: e655937cd5164 Version: 3.000000 Error Number: 10558 Short Message: Currency Not Supported for Card Type. Long Message: Your processor is unable to process the Card Type in the currency requested. Please try another card type. Error Number: 10400 Short Message: Transaction refused because of an invalid argument. See additional error messages for details. Long Message: Order total is missing. Everyone else successfully completes a payment. The Merchant account is US based and their card is US based. Any ideas?