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You file corporate taxes online in Canada by sending your T2 return electronically, and for most corporations it’s no longer a choice. For tax years starting after 2023, the CRA says a corporation that must file electronically and doesn’t gets a $1,000 penalty. The return is due six months after your year end.
Do I have to file corporate taxes online?
For most corporations, yes. The CRA’s page on completing your T2 return lists a few exceptions: insurance corporations, non-resident corporations, corporations that report in a functional currency, and tax-exempt entities under section 149 of the Income Tax Act. If you’re a normal small company with a Canadian bank account and dollar books, assume you’re in.
Mailing a paper return and hoping for the best can now cost you $1,000. So check your year end, and put the filing date in the calendar before anything else.
What do I need before I start?
Every resident corporation files a T2 each year, even when there’s no tax to pay. The exceptions are tax-exempt Crown corporations, Hutterite colonies and registered charities. A dormant company still files. It just files a return with little in it.
You’ll pick between the full nine-page T2 and the two-page T2 Short Return, if you qualify under Guide T4012. Most people don’t fill the form by hand. They use CRA-approved T2 software or an accountant who files for them, and the CRA’s Corporation Internet Filing FAQ describes how the electronic return is sent. If someone other than the corporation sends it, a signing officer has to complete and sign Form T183CORP first, and its amounts must match the electronic return.
| Item | What the CRA says |
|---|---|
| Filing deadline | Six months after the tax year ends |
| Return to use | T2, or T2 Short Return if eligible |
| Nil return | Still required |
| Penalty for not filing electronically when required | $1,000 |
What tax will the return show?
Work that out before you file, so the number doesn’t surprise you. Take a Canadian-controlled private corporation in Ontario with $300,000 of active business income for calendar 2026. The corporate tax calculator shows $27,000 of federal tax and $8,088 of provincial tax. That’s $35,088, or 11.7%, leaving $264,912 in the company.
A word on that 11.7%. Ontario cut its small business rate on 1 July 2026, and the calculator uses a blend for a calendar year. A corporation with a different year end will get a different figure. The tool also leaves out taxable capital and credits, and it handles passive income and associated companies only through two optional boxes.
When is the tax itself due?
Not on the same day as the return, and that surprises plenty of first-time owners. The CRA’s balance-due day page says most corporation tax is due two months after the end of the tax year. A Canadian-controlled private corporation that claimed the small business deduction can get three months if it meets the listed conditions. So a calendar-year company has until the end of February or March to pay, while the return can wait until June 30.
Where do people go wrong filing corporate taxes online?
The deadlines are the first trap. Don’t assume the filing and payment dates are the same, and don’t assume a late return is harmless because you paid on time.
Second, a return that’s late only because the books weren’t ready. Getting records in order takes longer than filing. If you keep the books through the year, the filing is a few hours. If you don’t, it’s weeks.
Third, forgetting the other returns. A company with staff has payroll to send in, and a GST/HST registrant has its own filing. The payroll remittance calculator and the GST and HST calculator help you size those up, and they run on different calendars from the T2.
Last, Alberta. Its provincial return, the AT1, is separate from the T2, and Alberta says most corporations must file it electronically for years beginning after 2024. The CRA’s own filing FAQ says Alberta and Quebec provincial returns can’t go through Corporation Internet Filing and are sent directly to those provinces. If your head office is there, read our Alberta corporate tax guide.
Should I do it myself or hire someone?
If you’ve got a simple company with no employees, few transactions and clean books, doing it with software is realistic. Once you have shareholders, dividends, associated companies or foreign activity, an accountant earns their fee. What accountants charge couldn’t be confirmed, so ask two or three for quotes and ask what’s included. Either way, you’re the one on the hook for the return, so read it before it goes.
Where does this information come from?
The filing rules come from the Canada Revenue Agency‘s corporation income tax return pages, read in October 2026. The tax example uses the 2026 federal and Ontario rates in our data. This is an independent site, and no government body is behind it.
Frequently asked questions
When is a corporate tax return due?
Six months after the end of the tax year, according to the CRA. The date the tax itself is due is separate, so check the CRA page.
Can I still mail a T2 return?
Most corporations must file electronically for tax years starting after 2023. A required filer who doesn't gets a $1,000 penalty.
Which corporations are exempt from e-filing?
The CRA lists insurance corporations, non-resident corporations, those reporting in a functional currency and section 149 tax-exempt entities.
Do I file if the corporation earned nothing?
Yes. Resident corporations file every year even with no tax payable, apart from a few types such as registered charities.
Is Alberta's AT1 filed with the T2?
No. The AT1 is Alberta's own return, and Alberta says most corporations must file it electronically for years beginning after 2024.
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