Financial inclusion has become a prominent development policy objective. Its promotion rests on the understanding that poverty and underdevelopment mainly result from financial constraints that individuals face. Better access to financial services, in particular via the use of mobile money services, is supposed to lift these constraints and allow for growth and development. After outlining this dominant approach and detailing its theory of change, this article challenges it on the basis of the mesoeconomic study (at territorial level) of areas particularly targeted by financial inclusion policies: Kenyan informal settlements. The study of their geography of money shows how the socio‐spatial flows of money shape people's economic constraints and opportunities. Based on this empirical account, it is argued that the poor are, first and foremost, in a situation of monetary exclusion, rather than being primarily financially constrained. The article conceptualizes monetary exclusion and highlights the theory and policy implications of this situation.