Ad Valorem Duty
A duty calculated as a percentage of the declared value of the imported goods.
An ad valorem duty is expressed as a percentage of the customs value (typically the transaction value, or the price paid for the goods). For example, a 5% ad valorem duty on goods valued at $10,000 equals $500 in duty. Most US and EU tariff rates are ad valorem. Some tariff lines use specific duties (per unit), compound duties (ad valorem plus specific), or mixed rates.