Public encounters are multifaceted dynamics in which relationships between citizens and the State take shape through political struggle for democratic accountability and socio-economic outcomes. Recent work calls for moving beyond understanding public encounters as face-to-face communication, but offers a limited conceptual foundation for understanding accountability dynamics in-between citizens and street-level bureaucrats and their implications for power and socio-economic inequalities. We draw on critical accounting research to conceptualise public encounters as a relational nexus of neoliberal discourse, accounting technologies and communicative practices that exerts relational power. Based on a critical-interpretivist ethnography of the UK Tax Credits System, we demonstrate how claimants in significant financial and emotional hardship ‘become accountable’ for their own tax obligations and welfare. By understanding public encounters in terms of relational power, we offer a critical, interdisciplinary perspective on how automated and punitive social welfare systems turn disadvantaged citizens into self-responsible subjects accountable to the State.