This paper describes the enumerations of informal settlements undertaken in 2010 by the National Slum Dwellers Federation of Uganda in the cities of Arua, Jinja, Kabale, Mbale and Mbarara, covering about 200,000 people. It describes how this federation was founded and subsequently developed through an earlier enumeration and initial work in informal settlements in Kampala. It also discusses the relationship between the federation and other actors, including the national government and Cities Alliance, and their role in supporting the formation of the federation. It explains how federation members developed the capacity to undertake the enumerations and later improved upon those skills, for example developing a GIS, to support the planning and implementation of upgrading by federation, local and national government agencies. The paper ends with a discussion of the way enumerations can encourage the rapid maturation of urban poor groups and their relationship with their cities and other development actors and the larger political context. [ABSTRACT FROM PUBLISHER]