If you ever receive an error when trying to book in a shipment that already has seemingly correct commodity data, this can happen when a commodity description doesn't match the commodity code, e.g if someone puts the commodity code for a "cotton shirt", but their commodity description is "wood table".
FedEx provides this handy tool for customers to check and find commodity descriptions for any item they need:
Step 1: Enter a brief description of the item and the destination then click 'Next'
Step 2: The tool should then ask you one or more questions about the item, see below:
Step 3: Once you've answered the questions the tool will then provide you with a list of potential HS codes and descriptions, see below: