We unpack the concept of "informal accounting systems" and bracket "vernacular accountings" based on the modality and source of legitimacy of such systems. Vernacular accountings are accounting and control systems that are self-generated by organizational actors in the context of their work and not officially sanctioned within the organizational hierarchy. We argue that these systems capture actionable knowledge from the epistemic perspective of their users. We identify three ideal types of vernacular accountings: vernacular accountings as an inventory of knowledge that employees construct to meet their task specific information needs; vernacular accountings as a defensive resource constructed and used by employees who resist or do not trust the formally sanctioned systems; and, vernacular accountings as organizational practice that has both pragmatic and epistemic functions and that facilitates distributed cognition. Drawing on an epistemic perspective that spans cognitive and social levels of analysis we develop theoretical propositions on the emergence and use of these three types of vernacular accountings.