This paper sets out broad parameters of a market-based biodiversity offset program under development by the government of New South Wales, AU. It is meant to elicit comments and suggestions for pilots in the Lower Hunter and the Far North Coast regions, which are set to begin in 2006 and end two years later. The authors explain how the new concepts of "biodiversity certification" and "biodiversity banking" will operate in areas where high population growth and economic development are transforming the landscape and causing irreversible biodiversity loss.