Prompting is an aspect of oral assessment that deserves more attention. There appears to be considerable variation in how practitioners conceptualise prompting and how it is deployed in practice. In order to unpack the term and promote the validity of its use in performance assessments, we present a taxonomy of prompting as a continuum of types, namely: presenting the task; repeating information; clarifying questions; probing questions; and finally, leading questions. We offer general principles for consideration when using prompting in oral assessment: neutrality; consistency; transparency; and reflexivity. Whenever oral assessment is planned, assessors should be appropriately trained in the type and degree of prompting required, and candidates suitably briefed to know what to expect. Overall, we aim to raise awareness that quite different behaviours tend to be subsumed under the general term ‘prompting’. This paper provides concrete guidelines for implementing the defensible and effective use of prompting in oral examinations, applicable to a wide range of assessment contexts.