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EY tax usually means the tax practice of EY, the big international accounting firm. That’s our assumption, and we make no claim about what it offers, where it works or what it charges. The useful question for a Canadian business is broader: when does it make sense to hire a large firm for tax, and what should you settle before you sign?
What does a tax firm do for a Canadian business?
At bottom it prepares and files what the CRA requires from you, and it talks to the CRA on your behalf. For a corporation, that means the yearly corporate return. Add GST/HST returns if you’re registered, and payroll remittances if you have staff.
Bigger firms also take on planning work, such as how to pay yourself or how to structure a group. That’s where the fee and the value both grow, and it’s the part you can’t judge from a brochure.
What is at stake in the numbers?
Before you shop, know your own bill. Take an Alberta CCPC (a Canadian-controlled private corporation). On $300,000 of active business income, the corporate tax calculator shows $33,000 of federal and provincial tax, an average of 11.0%. On $600,000 it shows $78,000, or 13.0%, because the first $500,000 is taxed at 11.0% and the rest at 23.0%.
| Alberta taxable income | Total corporate tax | Average rate |
|---|---|---|
| $300,000 | $33,000 | 11.0% |
| $600,000 | $78,000 | 13.0% |
Those are our calculator’s 2026 figures. Ontario is trickier. The calculator says Ontario cut its small business rate on 1 July 2026 and shows a prorated blend for the year, so treat any Ontario number as an estimate until you see the final rate.
Now compare a firm’s quote to the tax itself. If the fee is a large slice of a $33,000 bill, ask what you’re getting for it. That isn’t a reason to say no. It’s a reason to ask.
What should you ask before hiring a large firm?
We couldn’t confirm any firm’s fees, so we can’t tell you what’s typical. Instead, get these things in writing:
- Exactly which returns and filings are in the price
- Who does the work, and who you can call
- How they bill extra time, and what triggers it
- Which deadlines they’ll track for you
Ask who’ll actually prepare your return. The person at the first meeting may not be the one doing it. A smaller practice may suit a simple company better, and a large one may suit a group with several entities. Neither answer is wrong.
How does a firm get access to your CRA business account?
The CRA says a representative can be an accountant, a bookkeeper, a family member, a friend, a lawyer or another person you choose. For business accounts there are three levels. Level 1 is information only. Level 2 adds limited account changes. Level 3 is delegated authority, meaning the representative can authorize other representatives.
That third level deserves a pause. Do you want anyone handing your account access on to others without asking you? Most owners can start at Level 1 or 2.
The access lasts until you or the representative cancels it, or until an expiry date you set. You manage it through My Business Account. When you change firms, remove the old one.
Which other tools help before the first call?
Registered for sales tax? The GST/HST calculator shows the tax on a sale, for example $13.00 on $100 in Ontario. If you have staff, the payroll remittance calculator shows what you owe the CRA each pay period. And if you plan to pay yourself in dividends, check the personal side with the dividend tax calculator. A firm that can explain those three figures clearly is doing its job.
Mistakes and limits
Don’t hire on the name alone. A famous firm doesn’t change your tax rate. Don’t sign without a scope of work either.
The calculators here assume a CCPC with active business income. Companies with large taxable capital, passive income or associated companies sharing the small business limit can pay more, and the calculator doesn’t cover corporate payouts to owners.
Where the numbers come from
Representative and access-level rules come from the Canada Revenue Agency’s pages on authorizing a representative. Tax figures come from our calculators, built on 2026 federal and provincial data.
Frequently asked questions
What is EY tax?
We're assuming it means the tax practice of EY, the international accounting firm. We make no claim about its services, fees or offices.
How much corporate tax does a small Alberta company pay?
On $300,000 of active business income, our calculator shows $33,000, an average of 11.0%. On $600,000 it shows $78,000, or 13.0%.
Can an accountant deal with the CRA for me?
Yes. The CRA lists an accountant among the people you can authorize as a representative.
What are the CRA access levels for a business?
Level 1 is information only, Level 2 adds limited account changes, and Level 3 lets the representative authorize other representatives.
How do I end a firm's access to my CRA account?
Manage or cancel it in My Business Account. Access also ends on an expiry date if you set one.
- 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.