If you encounter the error: "Whistl error (400): Message: - Creating shipment has gone wrong: Invalid ZonesCode," this may be due to the selected delivery service.
To resolve this, ensure you are using the correct type of service for your shipment. For example, if you are shipping domestically (e.g., GB to GB), the service must be a domestic one, not an IOSS service. Please update the delivery service accordingly and try again.
Example of the error within Shiptheory
Have any further questions? Our Support Team would be happy to answer!