Welfare rorters across the country have been sent bills, demanding they repay a combined total of almost $1 billion or face paying interest as well.
The 170,000 cheats have debts dating back up to 15 years and they've been told to start paying the money back within a month.
The federal government is pursuing the former welfare recipients in an effort to recoup more than $900 million.
"All those being contacted no longer receive a benefit, but previously received payments they were not entitled to and have made no effort - in some cases for over a decade - to repay what they owe," Human Services Minister Michael Keenan said on Friday.
"Some cases involve serious criminality including one person who deliberately defrauded $800,000 from the Commonwealth and is still refusing to enter into a repayment plan."
People have been given 28 days to commit to a repayment plan or face being slugged interest charge, which currently sits at 8.77 per cent.
"As none are currently receiving welfare, the government believes most are now working and have the means to start paying back what they owe," Mr Keenan said.
"For those who refuse to take action, interest charges are only the beginning. My department will also look at other measures such as garnishing wages and tax refunds, or referring matters to external collection agents."
Will the interest be enough to prompt rorters to pay it back? Watch the full story and discussion above!