Question: how are ad valorem tariffs collected?
Answer: An import tariff is a tax collected on imported goods. ... Thus, if 1000 watches are imported, the US government collects $510 in tariff revenue. In this case, $510 is collected whether the watch is a $40 Swatch or a $5000 Rolex. An ad valorem tariff is levied as a fixed percentage of the value of the commodity imported.