If a person or company owes a certain amount of unpaid debt, there's a minimum amount and time limit to take the formal process to issuing a bankruptcy notice.
A bankruptcy notice is a formal demand for payment based on a final judgment or order. It must be for $10,000 or more and can't be older than six years.
For more information go to the Australian Financial Security Authority (AFSA) website, the agency that regulates personal insolvency. https://www.afsa.gov.au/insolvency/owed-money/bankruptcy-notice