He began his career at at RHM Foods in London before moving to the family firm of Warburtons Limited in Manchester. His hard work led to his promotion as factory manager. In the early 1980s, Brett went to Harvard and graduated from the prestigious institution with an MBA in 1985.
Back in England, there were stints at Imperial Bakeries and Warburtons Bread Division.
In 1991, Brett was appointed joint managing director (operations), becoming sole managing director (2001- May 2006) before he took up his current role of executive director.
Brett supports Bolton Wanderers Football Club and has served on its board. He has also been a member of the FA Council, though he no longer has any connections with football.
Brett also represents Warburtons Limited on the Council of Campden BRI - Europe's largest member owned food and drink research association.