The Statutory Interest rate for loans as set by the ATO is currently 7.4%. Many service providers will charge interest on unpaid accounts at 2-3%, some will use the current ATO statutory rate, and others will charge up to 10%, as well as a late fee. You are allowed to charge late fees and/or interest on your unpaid bills, if: Network Debt Recovery Home / Uncategorized / Is it legal to charge interest on overdue accounts in Australia? As an example, if you charge 10% interest rate on an account that was overdue on $1,000, the annual interest would be $100. You would then divide that by 12 to get a monthly overdue charge of $8.33. “We are exercising our statutory right to claim interest (at 8% over the Bank of England base rate) and compensation for debt recovery costs under the Late Payment legislation, because we were not paid according to our agreed credit terms.” Send the invoice today.