Lewis qualified as a chartered accountant in 1973 becoming a partner of Mercers Bryant chartered accountants, now part of HW Fisher, in 1976.

From 1981 he was finance director of Aukett Group plc, a multi-disciplinary building design consultancy where he oversaw their rapid expansion from a turnover of £800,000 to £19m and flotation on the London Stock Exchange in 1988.

In 1993 Lewis became finance director of The Pelican Group plc, a restaurant group best known for its Café Rouge brand, which during his involvement expanded from 14 to 150 restaurants with a turnover of £110m.

Since leaving Pelican in 1998, Lewis has acted as a consultant finance director to a variety of businesses, both public and private, providing advice on financial controls, systems development, arrangement and negotiation of finance and general business strategy.

Lewis is the Finance Director at Michael Aukett Architects.