https://www.nerdwallet.com/ca/personal-finance/what-are-tax-deductions
Deductions may include things like child-care expenses, moving expenses and professional dues, to name just a few. Once you’ve subtracted all your eligible deductions from your total income, you will arrive at your net income, which is line 23600 of your tax return.
After calculating your net income, you may still be eligible for a few more deductions that you can claim to reduce your income further.
Deductions from net income are listed from line 24400 to line 25600. These deductions are more limited in scope and will not be relevant to most Canadians. They include northern residents deductions, limited partnership losses and a Canadian Forces personnel deduction.
Once you’ve subtracted the applicable deductions from your net income, you will arrive at your taxable income, which is line 26000 of your tax return.
Common tax deductions in Canada
Some frequently-used deductions that will reduce your taxable income may include:
Contributions to a registered pension plan you have through an employer.
Employment Insurance premiums and Canada Pension Plan contributions.
Registered retirement savings plan contributions, including those made to a spousal RRSP.
Eligible union or professional dues.
Child-care expenses resulting from earning a living or going to school.
Support payments, like spousal support.
Moving expenses related to work, starting a small business or furthering your education.
Self employment deductions
Some deductions are exclusive to individuals who qualify as self-employed. These deductions, including business costs like advertising, bank fees, interest accrued on a business credit card, office supplies and home office expenses, reduce a self-employed person’s overall professional income.
If you’re self-employed and you have calculated the total income, including net professional income after deducting expenses, you can use the personal deductions mentioned above to reduce your taxable income further.
If you are uncertain what deductions you might qualify for, it’s wise to consult a professional tax expert or accountant or visit the CRA’s website.