Self-education costs are a particularly problematic area, with 34 per cent of Australians wrongly believing they can claim the associated costs, according to research from H&R Block.
A further 29 per cent get it wrong when it comes to work-related costs, H&R Block found.
On the documentation front, only 1 per cent of taxpayers are fully aware of which receipts they are legally required by the Tax Office to keep, while 26 per cent are unsure.
In spite of this knowledge gap, 97 per cent of Australians are confident in the accuracy of their tax returns.
This research comes as the ATO warns taxpayers and tax agents that it will be using new technologies this tax season to target dodgy returns.
This year the ATO has introduced real-time checks of deductions for tax returns completed online, which will help identify claims that are substantially higher than those of other people with similar occupations and income.
“Every tax return is scrutinised using increasingly sophisticated tools and data analytics developed by our ‘data doctors’ at the ATO,” said ATO assistant commissioner Graham Whyte.
“This means we can identify and review income tax returns that may omit information or contain unreasonable deductions.”