Lost receipts are costing Australian taxpayers about A$7.3 billion (NZ$9.4b) in total, or about A$1,000 each, according to a Commonwealth Bank survey.
The bank said that a study of more than 1,000 Australians in early July showed that one out of every two taxpayers misplaced receipts needed to support their tax return.
Twenty-five per cent of the lost receipts were dockets for stationery and office equipment, followed by receipts for fuel, parking, tolls, travel and internet usage.
The bank said the lost receipts were also costing taxpayers time as they searched for the dockets.
The average Australian taxpayer spends 2.2 hours looking for receipts and supporting documentation for their tax return.