WACH (French: Chambre de Cooperation de l'Afrique de l'Ouest, CCAO) provides settlement of payments services among central bank and other monetary authorities in West Africa. WACH was established in 1975 (began operations in 1976); headquarters are in Freetown, Sierra Leone. Membership includes the Central Bank of West African States (representing Benin, Burkina Faso, C"te d'Ivoire, Mali, Niger, Senegal, and Togo) as well as The Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mauritania, Nigeria, and Sierra Leone.