WRITTEN EVIDENCE FOR SUBSTANTIATION
Generally in order to have a legitimate tax deduction claim all deductions must have been incurred in order to derive your income. This is usually in the form of written evidence such as receipts and invoices if your claim exceeds $300. This limit does not apply to the below for example as special written substantiation evidence rules apply:
Car expenses using the cents per km method
Overtime meals allowance
Award transport payments
Travel allowance expenses
PRIVATE USE
Where an expenses has a partial private use purpose then it is only possible to claim the work related portion of the expense. To calculate this you may need to keep a diary record in order to determine a reasonable work use.
KEEPING YOUR TAX RECORDS
Our tax system relies on you to self assess your taxable income. For this reason you are responsible to ensure your claims are fair and that all income is reported. Generally as a taxpayer you must keep your written evidence for five years from the date you lodge your tax return. The records you need to keep depend on your personal cicumstances. If you are unsure you are better to keep too many records than not enough.