Accounting fees and the cost of tax prep software are only tax-deductible in a few situations:

- If you’re self-employed or earned rental income

- Commission employees may claim accounting fees and the cost of tax prep software as employment expenses.

- If your tax return is re-assessed and you consult a professional accountant for advice, those fees may be deductible in certain cases.

https://turbotax.intuit.ca/tips/tax-tip-deducting-income-tax-preparation-fees-and-software-expenses-...