This paper examines recent experiences in combating corruption in customs authorities from Sub-Saharan Africa. It argues that integrity reforms have been too focused on reforming formal institutions, and too little attention has been paid to the political economy of reforms and the role of informal institutions. In many customs administrations, patronage runs through networks grounded on ties of kinship and community origin. Patronage undermines the implementation of policies and rules-of-law more generally. Opportunities for accessing illegal income tend to become institutionalized, leading to the creation of parallel organizations within customs, in which posts are valued essentially on the basis of the illicit gains to which they provide access. In such settings, customs officers are torn between compliance with abstract bureaucratic norms and concrete expectations of their networks of social belonging. Accordingly, policy initiatives should focus more on measures that reduce the possibility or attraction of favoritism versus acting in the general public interest. This calls for anti-corruption efforts that are based on thorough analysis of the political economy of customs, in order to understand the interests and incentives of key players.