When the CRA does audits, the auditors always ask for proper receipts to support claims for deductions.
Acceptable receipts must show the date, the vendor’s name, the items purchased, and the amount paid. Credit card and bank statements are not considered proper receipts. So, keep your receipts for any expenses that might be a write-off. The CRA requires all accounting and tax records, including receipts, to be kept for at least 6 years.
You might wonder, what happens if you file your returns late? Say you just filed a 2017 tax return yesterday, and we are in 2023. Can you discard all your 2017 documents now? No, the 6-year requirement starts from the date when the CRA issues you a 2017 Notice of Assessment.