Understandings of informality commonly derive from research undertaken in states perceived as lacking the capacity to regulate the practices of their populations. This Interventions forum aims to expand the geographical parameters of empirical research on urban informality. A more global approach, we argue, also necessitates questioning assumptions that undergird this concept—in particular the underlying conception of the state. In this vein, this collection of papers aims to rethink theories of the state through the lens of informality, and vice versa, to inform and refine the concept of informality through a more thorough understanding of states. In so doing, the contributions engage with concepts that have been central both to theories of the state and to the study of informality, namely governance, agency, legitimacy, sovereignty and legality. Following this introduction setting out our theoretical approach, the Interventions forum unites five empirical studies that discuss the nexus of informality and states in contexts that have been researched less extensively from this perspective, each tackling one of the above‐mentioned concepts. Based on these different entry points, the papers provide novel angles on a state‐theoretical understanding of informality. A concluding essay brings these approaches together, reflecting on the possibilities of translating concepts to different sites.