Instead, these assets are written off over a period of time-based on the CRA’s specified depreciation charges. Rent paid to your landlord for the use of office space is tax-deductible. Keep a duplicate of the lease agreement and hire receipts as you will be required to offer these paperwork must you be audited by the CRA. A number of car expenses that you can claim are determined as a proportion of your business mileage within the yr over your whole mileage within the year.