The Canada Revenue Agency requires you to save your records for at least six years. However, if you are audited, it can be hard to remember the purpose behind some of your expenses and receipts. To make the process easier, consider marking your receipts with detailed notes.
It is recommended that you include notes about who the expense was for and how it relates to your income tax return. For example, if you have a receipt for lunch you bought while you were traveling to seek necessary medical care, you should note these details on the receipt. Otherwise, you later be unsure why you incurred the expense.
You also should note where you claimed the expense on your tax return.