INTRODUCTION: Obtaining a national training number in trauma and orthopaedic surgery (T&O) remains highly competitive. The aim of this study was to provide an insight into applicants' preparation for the T&O ST3 national selection interview. METHODS: A total of 292 junior doctors applying to T&O national selection in 2021–2022 were sent questionnaires using an online platform between December 2020 and December 2021. Participants were identified from those attending the annual OrthoRevision ST3 core interview knowledge course. Overall, 124 junior doctors (42%) covering all 16 surgical training regions in the UK completed feedback. RESULTS: While there is wide variation in how much applicants spend on interview preparation (e.g. books, revision websites, courses), 60% of candidates spend between £100 and £500, and 21% spend in excess of this. Almost half (43%) of the trainees start preparation three months before the interview, the preferred method being practice with colleagues (57%). Three-quarters (77%) use the OrthoInterview question bank. Free mock interview courses were only available to 33%, with candidates strongly in favour (80%) of the study budget covering preparatory courses, in addition to study leave being granted to attend these courses (86%). At the first attempt of obtaining a national training number, 66% were selective about where they would accept a job; for subsequent years, this dropped to 36%. CONCLUSIONS: For the first time, we present the preparation undertaken by applicants to T&O national training in the UK. Many candidates dedicate a large amount of time and money to the process, and are initially more selective about where they apply.