Abstract: Handover from an ambulance crew to emergency department (ED) staff is a short, crowded exchange on which much of a patient's early hospital care depends. Research on this interface has concentrated on what information moves across it and on the mnemonics used to structure the telling. A prior question has attracted much less attention: whether paramedics feel able to say what they know. This paper brings together evidence from organisational behaviour and from emergency care research to argue that prehospital-to-hospital handover is a psychological safety problem as much as an information-design problem.