Southern African Customs Union

SACU, established in 1910, includes Botswana, Lesotho, Namibia, South
Africa, and Swaziland. SACU provides for the free exchange of goods within
the area, a common external tariff, and a sharing of custom revenues.
External tariffs, excise duties, and several rebate and refund provisions
are the same for all SACU members. SACU's revenues are apportioned among
its members according to a set formula. These funds constitute a
significant contribution to each member's government revenues.