In 1973, Ng entered the business world, working as a bank officer at the Chung Khiaw Bank. Three years later, he became the managing director of Singapore Shuttle Bus, a City Shuttle Service operator. To create competition for the Singapore Bus Service, the only bus service in Singapore at the time, Ng started the Trans-Island Bus Services (TIBS) in 1982 and acted as the company's managing director. As a result of his work with TIBS and Singapore Shuttle Bus, Ng was named Singapore's Outstanding Manager of the Year in 1993. In 2001, TIBS was purchased by SMRT Corporation and later rebranded SMRT Buses. Ng retired from the company after overseeing the sale.