Nick Mitchell has served as the Human Resources Director and Deputy Managing Director of InterCity West Coast. In 1989 following the Clapham accident, he acted as the chief negotiator for the British Railways Board to re-structure Signal & Telecommunications' technician contracts. He acted as the unofficial lead negotiator for the Association of Train Operating Companies in resolving the role of the guard dispute during the late 1990s. He also served as Human Resources Director for Virgin Trains and the Human Resources Director of Southern Railway.

He has undertaken a number of consultancy roles including acting as a consultant to the GoAhead Group in setting-up London Midland, involving trade union negotiations. Since leaving the Go-Ahead Group in 2006 he served with the Railway Pension Commission and the GoSkills Board, where he chaired the Stakeholder Board. In 2007 he was appointed Chairman of the GoSkills Main Board, serving in this capacity until 2010.

Subsequently, he has acted as a consultant to the Department of Transport team responsible for bringing failing franchises back into public management and has assisted MTR on the introduction of the Crossrail project. He has an MA in Law and Employment Relationships and is a Fellow of the Chartered Institute of Personnel and Development.