Starting August 27, 2019, all calls to the CreateInboundShipment operation must include a ShipmentId from a previous call to the CreateInboundShipmentPlan operation. This is required for optimal placement in Amazon's fulfillment network. After this date, calls to CreateInboundShipment that do not include a ShipmentId will fail.
The Spain, UK, France, Germany, Italy, India, Australia, and Japan marketplaces are affected. In all other marketplaces it is already a requirement to include a ShipmentId with all calls to the CreateInboundShipment operation.
Developers with applications that call CreateInboundShipment without including a ShipmentId from a previous call to CreateInboundShipmentPlan are affected by this change.
If you have an application that is affected by this change, be sure to update your application's workflow. Ensure that all calls to CreateInboundShipment include a ShipmentId from a previous call to CreateInboundShipmentPlan.