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A tax firm becomes worth a look the day you incorporate. A corporation has to file its T2 return within six months of its year end, and the balance is generally due two months after that year end (three for some Canadian-controlled private corporations). So your tax firm’s calendar runs on your fiscal year, not on April 30.
What does a tax firm do that a preparer doesn’t?
Ask three firms and you’ll hear three lists, and we can’t vouch for any of them. In broad terms, a personal preparer files T1 returns. A tax firm handles the corporation’s return, and often the owner’s personal one too, since the two are tied together by salary, dividends and loans.
Scope is where the confusion starts. Some firms only file the T2 from numbers you hand them. Others keep the books, run payroll or file GST/HST. Ask what’s in the price and what isn’t. We couldn’t confirm professional fee levels on any official page, so we won’t quote them.
When are corporate returns and payments due?
The CRA’s own examples show how the six months work. The payment date comes first, and that’s the one people miss.
| Tax year ends | T2 return due | Balance due |
|---|---|---|
| March 31 | September 30 | Generally two months after year end, three for some CCPCs |
| September 23 | March 23 | Same rule |
| November 30 | May 31 | Same rule |
Read that last column twice. Your firm can file on time and you can still owe interest, because the money was due months earlier. We didn’t check the interest and penalty rules for this page, so read the CRA’s corporate pages before you plan around them.
What does a small corporation pay in tax?
The federal net rate is 15% on general income. For a CCPC claiming the small business deduction it’s 9%. Provinces add their own rates, and Ontario cut its small business rate on July 1, 2026, so the calendar 2026 figure is a blend.
Here’s a case. A Canadian-controlled private corporation in Ontario has $300,000 of active business income for calendar 2026. Our corporate tax calculator gives $27,000 federal and $8,088 provincial, so $35,088 in all, or 11.7%. That leaves $264,912 in the company.
Treat the Ontario piece with care. The blended 2026 rate is derived from the July change and isn’t printed on a CRA page, and a company with a different year end will land somewhere else. The calculator leaves out taxable capital and credits, and it covers passive income, associated companies that share the limit and dividends paid to you only through optional boxes.
How do you choose a tax firm?
Start with the questions. Who does the work, and who signs? What’s the fee and what triggers extra charges? When do you need to send records, in practice, so the return is filed by the due date? What do they do if the CRA sends a letter?
Then check credentials the way you would for any professional. Ask for the designation, and confirm it with the body that issues it. We couldn’t verify designation rules for this page, so that step is yours.
Also ask how the firm treats your pay. The split between salary and dividends changes your personal tax, and the dividend tax calculator shows what a dividend costs you personally. The self-employed tax calculator shows the other side, if you’re still unincorporated and wondering whether incorporating is worth it.
Where do things go wrong?
Most trouble comes from records, not from tax rules. Keep your business records for at least six years, and hand your firm complete bank and card statements, not a summary. Missing paper turns into missed deductions, and our guide to business deductions shows what usually qualifies.
The other trap is assuming your firm watches everything. It files what you give it. If you sold equipment, took a loan from the company or added a partner, say so. And if you need payroll numbers, the payroll remittance calculator gives you a rough monthly figure to check against theirs.
Where do the numbers come from?
Deadlines and the 9% and 15% federal rates come from Canada Revenue Agency pages, read on September 30, 2026. The Ontario blend and all dollar figures come from our corporate tax calculator. No connection with the CRA or any government body.
Frequently asked questions
When is a corporation's T2 return due?
Within six months of the end of its tax year. A March 31 year end means September 30, for example.
When is the tax itself due?
Generally two months after year end. Some Canadian-controlled private corporations get three months if they meet the CRA's conditions.
What is the federal corporate rate?
The CRA shows a 15% net rate on general income and 9% for a CCPC with the small business deduction. Provinces add their own.
Do tax firms all offer the same services?
No. Some only file the T2, others also keep books, run payroll or file GST/HST. Ask what is in the price.
What does a tax firm cost?
We couldn't confirm professional fee levels on an official page. Ask for a written scope and price.
- How Canadian income tax works: brackets and credits
How federal and provincial Canadian income tax stack up, what marginal and average rates mean, and how credits and deductions change your bill
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.