Billy graduated from Monash University, Australia with a double degree in Economics (majoring in Accounting) and Law in 1988. After completing his legal practical training course in Leo Cussen Institute of Melbourne, he was admitted to the Supreme Court of Victoria in 1989. He worked in Price Waterhouse Tax Services in Melbourne whereby he carried out research on the merger of family investment trusts and presented a paper on the Australian Budget 1989. Billy then joined Peat Marwick Tax Services for a year in 1990 and decided to chamber in Messrs Albar Zulkifly & Yap. Upon admission to the Malaysian Bar, Billy commenced practice in Messrs Oon Kong & Lee in August 1991 and later continued in Messrs Lee Choon Wan & Co in June 1992. He was involved in the listing of a few public listed companies and privatisation projects. In March 1997, he joined Messrs Lee, Perrara & Tan.

To date, Billy has conducted due diligence reviews for companies in a variety of industries including operations in China, Vietnam and Indonesia and the privatisation of a state-run company. Billy has also assisted 3 PRC applicants seeking initial public offerings in Malaysia in 2009.