How do Anglophone urban scholars know urban informalities? This article reviews three dominant ways of knowing urban informality, noting that, despite the profoundly rich insights they each provide, two critiques of the overall concept endure. These are that the concept is often imprecise, and that the contribution to knowing ‘the urban’ more generally remains clearly circumscribed to the ‘urban non-west’. In our view, these limitations curtail the possibilities of sharpening our understanding of the relationship to inequalities and injustices. We work with these critiques, suggesting that they represent two sides of the same problem, associated with binaries. In doing so, we build on the existing emphasis on practices and work across the three dominant ways of knowing urban informalities. This reveals that binaries are not held together magically and transparently so that each is the mirror opposite. Instead, the difference is constituted through unnamed aspects of common denominators – two of which we highlight (property rights and aesthetics) – and may be intrinsic to the way urban informality has come to develop. It is through the latent power relations that inhere in these common denominators that urban scholars can achieve greater conceptual precision and make different contributions to broader urban theory committed to challenging injustices.