A tax levied on imports (and, sometimes, on exports) by the customs authorities of a country to raise state revenue, and/or to protect domestic industries from more efficient or predatory competitors from abroad.
Use customs duty in a sentence
We had to pay a customs duty on the clothing we bought in Mexico when crossed the border to our home country.
I didn't realize that the imports would be taxed and then they told me it was the customs duty, but that didn't make me feel better.
You need to factor in the customs duty to any cost of a product or resource that you will be bringing in from overseas.