A specific duty is a duty calculated as a fixed dollar amount per physical unit of imported merchandise — typically per kilogram, per liter, per pair, per dozen, or per piece. Unlike ad valorem duties, specific duties are independent of the merchandise value.
The formula:
Duty owed = Quantity × Specific rate
For example:
- HTS 0406.30.10.00 (Processed cheese, not grated, less than 0.5% butterfat): rate of $0.10/kg — a 10,000 kg shipment owes $1,000 regardless of declared value
- HTS 2401.10.21.00 (Wrapper tobacco, not stemmed): rate of $0.40/kg
- HTS 6406.10.65.00 (Formed uppers of textile materials, for footwear): rate of $0.077/kg (often part of a compound rate)
Specific duties dominate certain product categories:
- Agricultural products — Meat, dairy, sugar, tobacco, certain produce
- Textiles and footwear — Particularly in compound-rate form
- Petroleum and certain raw materials
The persistence of specific duties in these categories reflects historical protectionism — Congress chose units rather than percentages because, as average unit values rose, ad valorem rates would have to be raised legislatively while specific rates remained automatically protective in absolute terms. The opposite is also true: a flat $0.10/kg rate may be effectively meaningless against today's high-value gourmet cheese imports.
Specific duties require precise quantity reporting on the Entry Summary. The classification's "unit of quantity" — printed in column 1 of the HTSUS — controls whether the duty is calculated on net weight, gross weight, dozens, pairs, or another measure. Mismatches between declared and actual quantity are a frequent source of liquidation errors and importer overpayments.
Compare to ad valorem duties (percentage of value) and compound duties (a combination).