Intermediaries are communication experts who facilitate communication between individuals with communication needs and the criminal justice system. In executing the role, intermediaries interact with police, lawyers, judges and other criminal justice professionals. But is the intermediary a professional in its own right? This article argues that a more useful question to ask is whether intermediaries engage in what Andrew Abbott terms ‘professional work’. It reveals how the role tussles for legitimate control over its work tasks through the staking of ‘jurisdictional claims’. Intermediaries do so through the performance of ‘boundary work’ which involves the construction and negotiating of boundaries that mediate interaction. This article presents findings from thirty-one in-depth, semi-structured interviews with intermediaries and judges in England and Wales and Northern Ireland. It concludes that the future of the intermediary role and its work depends largely on the type of ‘jurisdictional settlement’ which its practitioners seek to carve out.