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Do you need a CPA for your taxes? Most employees with a T4 and a few slips don’t. If you run a business, own a corporation or file a return with several moving parts, a CPA who does tax work can earn the fee. Take a sole proprietor in Ontario with $80,000 of net business income. Our self-employed tax calculator puts income tax and both halves of CPP at $22,126, or 27.7% of that income. That’s the size of the bill a good tax accountant works on.
What does CPA tax work actually cover?
The letters stand for Chartered Professional Accountant. Provincial and territorial CPA bodies grant the designation and keep the member registers, so there’s no single national list to check. Tax work can be small, like a T1 for a family, or large, like a corporate T2 with a shareholder loan and a dividend plan.
A CPA can also help you answer when the CRA writes to you, and can tell you before year end what a purchase or a salary change will do to your bill. That advance advice is where most of the value sits. Filing on time is the easy part.
Do you need one or will software do?
Software is fine when your income is slips, the claims are ordinary and nothing changed in your life. Start with the income tax calculator to see roughly what you owe, then file with certified software if the number matches your expectations.
Hire help when one of these is true.
- A business or a company is involved.
- Property, shares or crypto were sold and the gain isn’t obvious.
- Two countries or two provinces were home in the same year.
- A CRA letter arrived and it makes no sense to you.
The dividing line isn’t income. It’s whether the return needs judgement, and that’s rarely a question of how much you earn.
What a self-employed year looks like in numbers
The table comes from the same calculator, Ontario, no other income. CPP is shown for both halves, because a self-employed person pays the employee and employer parts.
| Net business income | Income tax | CPP | Total | Share of income |
|---|---|---|---|---|
| $40,000 | $4,221 | $4,344 | $8,565 | 21.4% |
| $80,000 | $13,234 | $8,893 | $22,126 | 27.7% |
| $120,000 | $25,482 | $9,293 | $34,774 | 29.0% |
Now add a $10,000 deduction to the $80,000 case. The total drops to $19,011, so the deduction saved $3,115. Finding deductions you’re entitled to and can prove is a real job for a tax accountant. Inventing them is the opposite, and the CRA lists false claims among the warning signs of a bad preparer.
How do you check a CPA before you hire one?
Get the person’s full name and the province they’re registered in, then look them up on that province’s CPA register. If they’ll sign off on financial statements, check for a public accounting licence too. And find out who will actually prepare your return, because at some firms it’s a junior working under a partner, which is fine if you know it.
The fee matters as well. Is it hourly or fixed? Get the answer in writing. We couldn’t confirm typical fee levels for any province, so we won’t quote one. Any figure you see online is one firm’s price.
The CRA keeps a directory of preparers certified to file electronically, and it says never to sign a blank form. Its warning list is worth reading before you sign anything: a preparer who discourages a second opinion, promises an unusually large refund or claims the CRA approved a scheme is the one to walk away from. And the return is still yours. The CRA expects you to keep your documents for six years.
Common mistakes with a tax accountant
The first is showing up in March with a shoebox. Gather your slips, receipts and last year’s notice of assessment first. The tax instalments calculator is worth a look in the same week, since the CRA asks for quarterly payments once your net tax owing passes $3,000 (or $1,800 in Quebec) in the current and one of the two previous years. Miss those and interest builds daily.
The second mistake is paying for a return and never reading it. Look at the total income line and compare it with your own slips. The third is leaving the year-end talk until January. If you want a CPA to save you money, meet in the autumn, when a salary choice or an RRSP top-up can still change the result. Our RRSP calculator shows what a contribution does to your refund.
Where the numbers come from
Tax figures come from our own calculators, which use the 2026 federal and Ontario rates and Canada Pension Plan amounts published by the Canada Revenue Agency. The instalment rules come from the CRA’s instalments pages. The registration and licensing points come from CPA Canada and the provincial bodies. We’re not connected with the CRA, any CPA body or any accounting firm.
Frequently asked questions
Do I need a CPA to file my taxes?
Not if your income is slips and your claims are ordinary. Certified tax software handles that. Help pays off with a business, a corporation, property sales or a CRA letter.
How do I check that someone is a CPA?
Look the person up on the register of the provincial or territorial CPA body where they work. Each province keeps its own list.
What does a CPA charge for a tax return?
We couldn't confirm fee levels, and they vary by firm and by how complex the return is. Ask for a fixed quote in writing.
Can a CPA file my return for me?
Yes, if they're certified to file electronically. You review the return and sign the T183 authorization first, and you keep the documents for six years.
Will a CPA reduce my tax bill?
They can find claims you're entitled to and plan the timing. They can't change the rates, and a claim you can't back up will be refused.
- How to choose a tax preparer in Canada
How to decide if you need a tax preparer, what a preparer does, the questions to ask before you hire one and where to find free help in Canada
Information only. This page is general information, not tax, legal or accounting advice. Tax-Services.ca is an independent publisher: we don't prepare or file tax returns or offer tax services, and we have no connection with the CRA, Revenu Québec, any government or any company named on this page. Check the figures that matter with an official source or a qualified professional.