Supervising student practitioners remains an important part of the work of registered nurses, midwives and specialist community practitioners. The Nursing and Midwifery Council (NMC) introduced sign-off mentors in 2006. Sign-off mentors are required to make decisions about whether a final placement student has achieved the required standards of proficiency for entry to the NMC register. Existing, experienced mentors who wish to become sign-off mentors must be supervised signing off final placement students on NMC-approved courses on at least three occasions by a practitioner with existing sign-off mentor status. This article describes a collaborative citywide approach to the preparation and support of sign-off mentors in Leeds.