Yes. Two reasons: (1) we will auto-categorize your business card expenses, and (2) many tax write offs are split personal / work expenses. Examples: gas if you drive your car for both work and personal use, home office expenses, phone bill, electronics, etc. Those write offs are really easy to miss out on!
In Canada, the CRA wants self-employed people and business owners to keep track of their odometer readings and log all trips that are for a business purpose. They could ask for that if they audit the individual. The fraction of business use kilometers versus driven is then applied to recurring expenses like fuel and oil, and also to capital cost allowance: the yearly depreciation of the vehicle asset.