Foreign resident capital gains withholding (FRCGW) must be withheld on all real property (property) sales unless the vendor is an Australian resident for tax purposes.
All Australian residents (for tax purposes) selling or disposing of Australian real property (property) must have a clearance certificate and give it to the purchaser at, or before settlement.
Without a clearance certificate, the purchaser must withhold up to 15% of the sale (or market value if not sold at arm’s length) for foreign resident capital gains withholding (FRCGW) purposes.
Source: Australian Taxation Office