Guy was educated at Wellington College and obtained a law degree from Exeter University. He qualified in 1972, became a partner in the Company and Commercial Department in 1974 and head of the department in 1992. He was appointed as the Firm's Managing Partner in 2000.

Guy specialises in corporate acquisitions and disposals, corporate re-organisations, including restructuring and demerger; commercial contracts and terms of business. He also has considerable experience in employment and partnership matters, IT and intellectual property.