After leaving the Armed Forces, Gary worked freelance in a variety of industries, including petrochemical, pharmaceutical, event management and construction. In the early 1990s, he joined the United Nations High Commission for Refugees and was part of the team that set up humanitarian aid logistics in war-torn former Yugoslavia.

Gary joined forces with long-time friend Mark Dobson to create Wilson James Ltd, to provide security, logistics and aviation services to many blue-chip clients and critical national infrastructure.

Wilson James Ltd now employs over 6500 people and has offices in Westcliff, London, Heathrow, Manchester and Aberdeen. In March 2006, Wilson James launched the first dedicated construction materials consolidation centre for the materials support of London construction projects.

Gary is Chairman of Wilson James; he has also chaired several Government Quangos including; Business Link, The Thames Gateway Partnership and The Olympic Legacy Board for the East of England. Gary led the Wilson James team that delivered the Security and Logistics for the Athletes Village. Wilson James are the Logistic Integrator for Heathrow Airport and Hinkley Point C. He is a published author, conference speaker and was Commander of The Staff Corps (ELSC) from 2019 until July 2023.

Gary is dedicated to improving construction through greater efficiency in the disciplines of logistics and supply chain management.

In 2012, Gary was awarded an OBE for his services to regeneration.