Customs unions represent a form of deep economic integration. The Southern African Customs Union (SACU), comprising four small members - Botswana, Lesotho, Namibia, Swaziland (BLNS) - and South Africa, is the world's oldest customs union (it was formed in 1905) and arguably the most successful scheme of regional integration (RI) in sub-Saharan Africa (SSA). Although SACU is hardly replicable due to its very specific historical origin, it may serve as a model for RI, since RI schemes have not visibly reaped substantial benefits until recently, despite featuring prominantly in political agendas and rhetoric. Indeed, SACU is regarded by many as a possible core for economic RI of Southern Africa. Unexpectedly to most observers, SACU has survived the transitions to political�Â�  independence of its smaller members and the South Africa's democratic transition in 1994. In an eight-year long process (1994-2002), the SACU agreement of 1969 was renegotiated and replaced by the agreement of 2004 (SACUA 2004). This agreement transformed SACU from a body administered unilaterally by South Africa (with compensation of the smaller members) to an independent institution with equal partners. The smaller countries (BLNS) gained participation in policy-making but lost the basis for compensation. The 'key' challenge of the new SACU is to show its ability to manage the different interests of the small countries (BLNS) and the comparative giant South Africa. The new agreement has ambitious aims: it implies a substantial redefinition of the 'institution' and establishes a number of common institutions and common policies.