Every contract for residential property in New South Wales comes with a five business day cooling-off period for the benefit of the purchaser (unless the property is sold at auction). This scenario locks you in to selling the property to the purchaser however the purchaser can pull out and rescind contracts during the cooling-off period. If they decide to do this then they will forfeit 0.25% of the purchase price to you.
As the vendor of the property you can insist on the purchaser waiving the cooling-off period and providing what’s called a Section 66W Certificate. This Certificate is signed by the purchaser’s conveyancer and when it is provided there is no cooling-off period and the purchaser is bound to settle the contract from day one. This scenario is common where you might have a number of parties interested in your property who are all offering around the same price with similar conditions. You will be guided by your real estate agent as to which option will work best for you depending on the circumstances of your sale.