If you have a loan with the ATO (including a compulsory higher education loan program HELP debt or overseas levy) and you can't pay the amount on time, you may be able to apply to defer or amend your payment. 

This means the ATO may either not raise a repayment (they will defer your payment to a later date) or reduce the repayment amount toward your loan (amend).

You will need to show that making the payment has or will cause you serious financial hardship or that there are other special circumstances that should be considered. This means you will need evidence to support your request.