Professions enjoy privileged positions and expend efforts to sustain these in public and interprofessional domains. This research investigates a previously vacant and largely uncontested jurisdiction in the UK charity sector that was claimed, maintained and subsequently expanded by the accountancy profession. We find that the dominant involvement of the accountancy profession leads to a charity regulatory framework that centralises the giving of an account. Over time, the accountancy profession advances highly specialised charity accounting and novel disclosures in annual reports. The study contributes to a deeper understanding of professions expanding jurisdiction in the absence of competition. In our conclusions, we scrutinise implications for trust and legitimacy in the UK charity sector, balancing increased information demand on charities with accessibility to users.