In 1959, the four territories of French Equatorial Africa joined the Equatorial Customs Union (Union Douanière Equatoriale— UDE), within which goods and capital flowed without obstruction. The UDE was expanded in December 1964 to include Cameroon and together they formed the Central African Customs and Economic Union (Union Douanière et Economique de l'Afrique Centrale—UDEAC). The Republic therefore had no customs system of its own. In early 1968, the Central African Republic left the UDEAC to join an economic union with Zaire and Chad, but in December 1968 it returned to the UDEAC. As of 1993, the Central African Republic was a member of both UDEAC and CEEAC.
The UDEAC covers the entire range of commodity trade and bans all import and export taxes between member states. Goods and merchandise originating in member states are exempt from various taxes except in special circumstances. The gains derived from import duties in member states go into the state budgets, but to offset the advantages gained by transit trade, especially to coastal countries, a share of import duties is deposited in a common fund. There is a uniform customs tariff levied against all third parties, but since the UDEAC countries are associated with the common market, imports from EU countries receive a reduction in customs duties. Imports from outside the franc zone require a license. Customs evasion through the smuggling of goods across the Democratic Republic of the Congo and Cameroon borders is a serious problem. Such goods are sold at 10–40% off the price of legitimate items, depriving the government of significant revenue.