Tariffs: Theory and PracticeLords Library research briefing, 27 March 2019Information on the use of tariffs in international trade and the UK`s options after leaving the European Union The Southern African Customs Union and the countries of Mozambique`s trading bloc have been added to the list of signed agreements. Some new agreements will not enter into force until the UK leaves the EU. Trade is then done under the conditions of the World Trade Organization (WTO). . . .