Born and raised in Reading, Berkshire,[1] Gill studied at the University of Birmingham (BCom Industrial, Economic and Business Studies, 1978), becoming a Chartered Accountant with Price Waterhouse in 1981. After a two-year spell in San Francisco, he left the firm in 1986 to join The BOC Group in its corporate finance department, and then Avis Rent a Car System in 1990. At Avis, he was responsible for the disposal of the European leasing business to GE Capital for US$1 billion in August 1992.