How does urban migrant and refugee settlement occur in face of national inaction on immigration policy? This paper focuses on recent migration to Cairo, a Global South megacity that is home to migrants and refugees from across sub-Saharan Africa and the Middle East. Using in-depth fieldwork, it examines the informal policies that have developed in the absence of national legislation, and explores the impact these have on: (1) the ability for individual migrants and refugees to participate socially, politically and economically; (2) the ability for civil society organizations to organize, provide social services, or engage in activism; (3) occasions when the Egyptian state will forego its hands-off approach in favour of direct intervention. This informs our understanding of the relationship between national policy, informal urban governance, and migrant and refugee settlement in the context of Global South cities, with potential applications to other urban environments.