A Practice Note providing a broad overview of US and international regulation of tariffs, also known as customs duties, and discussing the roles of US Customs and Border Protection (CBP), the US International Trade Commission (ITC), the Office of the US Trade Representative (USTR), the World Trade Organization (WTO), and free trade agreements (FTAs) such as the United States-Mexico-Canada Agreement (USMCA), which replaced the North American Free Trade Agreement (NAFTA).