In 2000, Mr Tsang joined PolyU's Department of Accountancy (now School of Accounting and Finance) as their half-time English technical writer, a post which he held for four years. During this period, he also did part-time English teaching at the School of Continuing Studies of The Chinese University of Hong Kong, the Hong Kong Management Association, and the Mechanical Engineering Department of PolyU. For his experience in copywriting, Mr Tsang was often approached by companies such as The Hong Kong Jockey Club, The Hong Kong Management Association, International Gold Coins, Reader's Digest, St Honore, and Universal Music to take up creative writing projects.
Mr Tsang joined HKCC in 2004 as a full-time lecturer for English subjects. Besides teaching and subject team management, he also takes up editorial, marketing and management duties and is currently the Chairman of the Admission and Marketing Committee and the Discipline Team Leader of the English team. In 2007, Mr Tsang was bestowed the HKCC Outstanding Teaching Award.