Refund administration fee

When an order refunds, Amazon returns the referral fee minus a refund administration fee: the lesser of $5.00 or 20% of the referral charged. On a $30 item with a $4.50 referral fee, the refund costs you $0.90 in kept commission — before FBA return processing, unsellable-grade losses, and the fulfillment fee that never comes back.

Alone it is pocket change; multiplied by return rate it belongs in unit economics — a 10% return-rate product carries it as a real cost line. Fold it into the honest returns model: refund admin + non-refundable fulfillment + return processing where applicable + salvage-value haircut = what a return actually costs.