This paper explores why taxation reforms are so different in fragile states, the conditions in which they occur, and what can be done to make these reforms more successful – including contributing, whenever possible, to state-building. Based on extensive engagement and fieldwork in the Sahel and other regions in sub-Saharan Africa (including Central and West Africa, and Somalia), this multidisciplinary paper builds on findings regarding taxation history in Africa, as well as existing research in anthropology and political economy. The paper explains why several prerequisites, such as state legitimacy or a centralised taxation power, are not present in most countries affected by fragility, conflict and violence (FCV), and, thus, why in many cases enforcement is impossible. It also explores the continuity between the institutions of colonial administrations and current tax and customs administrations, including why major changes cannot be expected in a short period of time. The level of taxation in FCV countries is mainly the result of bargaining processes between powerful actors.