International trade, it is also known as a duty or customs duty. A tariff is a tax that a country levies on imported goods and services. Based on domestic policy and relevant international trade agreements, each country determines what tariff, if any, it applies to imported goods. In the US, the Harmonized Tariff Schedule (HTS) lists the tariffs that the US charges for all imported goods. US Customs and Border Protection collects US tariffs on goods after the goods have gone through customs clearance.

The US International Trade Commission maintains and publishes the HTS in print and on its website (see ITC: Official Harmonized Tariff Schedule). This federal agency also provides an interactive database that has product-specific information on US:

(See ITC: US Tariff and Trade Data for a Specific Product.)

Countries generally use tariffs to restrict imports, reduce trade deficits, or raise tax revenue. Tariffs increase the cost of importing products, which makes them more expensive for consumers to purchase and creates a price advantage for locally produced goods.

The oil & gas industry, it is a rate schedule published by a regulated entity for its services. In addition to a rate schedule listing charges and fees for each service, tariffs also include the terms and conditions for the service and a form of the service agreement. Tariffs usually must be filed with and approved by the applicable regulatory authority, such as the Federal Energy Regulatory Commission, or a state public utility or applicable regulatory commission.