If you are claiming more than the reasonable allowance amount, you must keep records to show the full amount you spent, not just the amount over the limit. These records include:
a travel diary if your travel is six or more nights in a row – that is, a document that shows the dates, places, times and duration of your activities and travel
invoices, receipts or other documents showing your travel expense details. If it is too difficult to get a receipt for a meal you purchased – for example, if you purchase a meal from a vending machine – you can keep diary entries as your proof of purchase.
If you do not receive a travel allowance, you must keep all of your records.
If you receive a travel allowance that is more than the reasonable allowance amount, you must show the allowance as income on your tax return at item 2.
Sections within Work-related overnight travel expenses