Freight class is a standardized classification system used to determine the billable weight and risk of a shipment, ranked from 50 (lowest shipping cost) to 500 (highest).

When creating a shipment to send to Amazon with a partner carrier, you are expected to provide accurate packaging inputs, which trigger a freight class estimate. If you are unsure of your shipment's freight class, choose the Estimate my freight class option during the Shipping charges step of the Prepare Shipment workflow. If you chose that option, you will be asked to accept Amazon's estimated freight class.

Note: If your freight class is too low, you will see the following message: "The freight class you entered is too low. Click Accept to use the freight class estimator tool or click Reject to continue with your current selection. However, repeated inaccurate entries could lead to chargebacks or suspension from the FBA program."

Be aware that shipments with rejected freight class estimates are subject to further investigation, and recurring issues with packaging inputs may lead to Amazon disabling your ability to reject freight class estimates. If you find you cannot manually enter your freight class, Amazon has likely temporarily removed this feature due to recurring freight class discrepancies with your shipments. This privilege will be automatically reinstated quarterly.

For more info, see the Amazon Partner Carrier freight class help page.