Ad valorem duty
Also: percentage duty
A duty charged as a percentage of the customs value — the most common form of import duty (e.g. 5% of the entered value).
Definition
Ad valorem is Latin for "according to value." An ad valorem duty is simply a percentage of the customs value, so a higher-value shipment pays proportionally more.
The alternatives are a specific duty (an amount per unit, like $0.51/kg) and a compound duty (both a percentage and a per-unit amount). Section 301 and 232 additional tariffs are almost always ad valorem, which is why they stack cleanly on top of a base rate.
Worked example
A 16.5% ad valorem rate on $6,000 of goods is 0.165 × $6,000 = $990, regardless of how many units that represents.
Related codes & tools
Related terms
Sources
Definitions are informational, not customs rulings. Confirm rates against the schedule of record and see our methodology & disclaimer.