This article utilises Lewis’ (1997) ‘Sense of Entitlement’ Theory (SET) to investigate how individuals who are part of family arrangements other than the nuclear family feel (un)entitled to organisational work-family support, and to progressing their careers. In-depth interviews with 39 individuals who live in non-nuclear family arrangements, specifically lone parents, repartnered parents, and stepparents, were conducted, within the UK. We extend SET by unravelling the relationship between sense of entitlement to work-family policies and career progression, demonstrating how family arrangements play a previously unrecognized role in shaping this relationship. We furthermore show how family arrangements interact with other contextual factors such as gender, ideal worker norms and organisational climate. We organise these findings in a novel framework, extending SET and showcasing its dynamic nature. Also, recommendations for practice and organisational research are made.