Preston was born in 1946 in Indonesia, but he spent the best part of his first 30 years in Hong Kong where he received secondary education and worked for a number of years for the Hong Kong Government. When he resigned from the HK public service, he was an Executive Officer having worked for 3 government departments in Hong Kong. In the early 1970s, Preston spent 3 ½ years working in a small island in Central Pacific, before he migrated to Australia in 1978.

He studied part-time for his accounting degree in Australia and graduated in 1984. He became a CPA in 1987. For the first 10 years in Australia, he worked in Melbourne, first as Office Manager of a motorcycle company, and then as the Chief Accountant & Company Secretary of a medium-sized hi-tech organization with branches in all major cities in Australia as well as foreign offices in New Zealand, Singapore, and Hong Kong. Preston resigned from paid employment in 1988 to commence his private practice as a Registered Tax Agent and a Registered Migration Agent. As at 2024, 45 = Registered Tax Agent, 24 = Registered Migration Agent (as I discontinued rego in 2011)

An open-heart surgery in 2011 rendered him to discontinue registration as a Registered Migration Agent, but he continues to work as a Tax Agent without interruption. While registered, Preston had been responsible for assisting no less than 1,500 families to migrate from various parts of the world to Australia, including some 200 business migrants & their families, and helping another 400 students to study in the UK, Switzerland, New Zealand, and Australia. His experience in the Australian migration industry commenced in 1987 when he was appointed as an Accredited Business Migration Agent (BMA 057) entrusted with the responsibility of assessing and approving business skills of intending business migrants on behalf of the Immigration Department in Australia.

The BMP Program discontinued around 1993 when Preston was automatically granted the qualification of a Registered Migration Agent when the present registration regime came into existence with the establishment of the Migration Agents Registration Authority. Recently, Preston has been focusing his attention in establishing an accounting franchise in assisting academically qualified accountants to acquire practical experience in meeting the newly introduced requirements for registration as Registered Tax Practitioner (Agent) in Australia.