The Australian Tax Office (ATO) says it will be tripling the number of audits it conducts on individuals, as it looks to close a gap of close to $9 billion in lost tax revenue.
The A-T-O says the biggest problem is people falsely claiming work-related and rental property expenses.
Whether it's a simple mistake on a tax return or those deliberately cheating the system, around six per cent of individual tax claims are wrong.
The Australian Tax Office (ATO) has found $8.7 billion has been lost from tax revenue from individuals alone, with seven out of the ten returns audited having at least one error.
The gap from individuals has also been found to amount to more than three times the loss from large companies.
A-T-O spokesman Neil Olesen says the tax office will be looking to get that money back.
Mr Olesen says the biggest problem has been from people claiming work-related expenses and expenses relating to rental properties.
The A-T-O says people doing their own tax had a lower rate of errors than returns prepared by tax agents.
The Institute of Public Accountants' chief executive, Andrew Conway, says while there are some rogue agents, most do the right thing.
The Institute is now warning Australians as they prepare to lodge their tax return to not to mislead their agents in order to maximise their return.
Mr Conway says honesty is the best policy.
The A-T-O says it will be using additional funding from this year's budget to triple the number of audits it conducts.