Through a close reading of scattered, disparate, and largely unconnected secondary sources, supplemented with the analysis of primary sources, and backed by economic theory, this paper explores the origins, development, and socio-economic impact of so-called cosignatory lending institutions. These historical institutions were designed to issue small loans to small businesses and households and shared a reliance on cosigners to secure loans and on weekly instalments to repay them. Their shared lending format was flexible enough to display regional variations and this enabled cosignatory lending institutions to operate in societies characterized by notable differences in wealth and economic structure. It also allowed cosignatory lending institutions to fare better in a more urbanized, heterogeneous context than the more well-known credit cooperatives. As such, this systematic overview helps us better understand how credit markets were made more inclusive in urban contexts, which historical circumstances played a role in this, and perhaps even whether and how the success of cosignatory lending institutions may be replicated in present-day developed and less-developed economies.