The eruption of disruptive digital platforms is reshaping geographies of housing under the gaze of corporations and through the webs of algorithms. Engaging with interdisciplinary scholarship on informal housing across the Global North and South, we propose the term ‘digital informalisation’ to examine how digital platforms are engendering new and opaque ways of governing housing, presenting a theoretical and political blind spot. Focusing on rental housing, our paper unpacks the ways in which new forms of digital management of risk control access and filter populations. In contrast to progressive imaginaries of ‘smart’ technological mediation, practices of algorithmic redlining, biased tenant profiling and the management of risk in private tenancies and in housing welfare both introduce and extend discriminatory and exclusionary housing practices. The paper aims to contribute to research on informal housing in the Global North by examining digital mediation and its governance as key overlooked components of housing geographies beyond North and South dichotomies.