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Form 1120 is not a Canadian form. It’s the U.S. Corporation Income Tax Return, filed with the IRS by domestic U.S. corporations, and a calendar year company sends it in by April 15. A Canadian corporation files a T2 with the CRA instead.
Who files Form 1120?
The IRS says domestic corporations file it to report income, gains, losses, deductions and credits, and to work out their tax. “Domestic” means a company set up in the United States. If you run a Canadian business, you’re probably looking at the wrong form, unless you own a U.S. company.
A Canadian corporation doing business in the United States isn’t automatically in the same spot. The IRS page points foreign corporations to a different return, Form 1120-F. If you have to file that one, and what it covers, depends on how you operate in the U.S., and we haven’t researched it here. A cross-border accountant can answer that in one meeting.
How does it compare with the Canadian T2?
| Item | U.S. Form 1120 | Canadian T2 |
|---|---|---|
| Who files | U.S. domestic corporations | Corporations resident in Canada |
| Filed with | IRS | CRA |
| Filing date | 15th day of the 4th month after year end | Six months after year end |
| Extension | Form 7004 | Not confirmed for this page |
| Balance owing | Not confirmed for this page | Two months after year end, three for a qualifying CCPC |
For a December 31 year end, the 1120 is due April 15 and the T2 on June 30. The U.S. date comes first, which catches Canadians who assume both run on the Canadian calendar.
What if my Canadian company owns a U.S. company?
Then two returns are in play. The U.S. company files Form 1120 in the U.S. Your Canadian company files its own T2, and the CRA expects you to report the foreign company on Form T1134 as a foreign affiliate, which is due 10 months after your year end for recent years. Profit taxed in the U.S. isn’t automatically ignored in Canada, and how the two systems fit together is where an adviser earns the fee.
To get a feel for the Canadian side, use the corporate tax calculator. On $300,000 of active business income for a small CCPC, it shows $27,000 of federal tax, the 9% small business rate, and then adds your province. It doesn’t handle foreign income or credits for U.S. tax, and we didn’t confirm U.S. rates for this page, so we don’t compare the two.
What do you need before filing either return?
The same base material, really. An income statement, a balance sheet, a list of expenses with receipts, and a clear picture of what was paid to owners. If you pay yourself in dividends, work through the dividend tax calculator so you know what lands on your personal return. The profit margin calculator is a quick check on your books before an accountant sees them.
Mistakes that cost time
Searching for “Form 1120” and filling in the first PDF you find is the classic one. Check the country, the tax year and whether the entity is domestic.
Next, using the Canadian year end for the U.S. company. Each country works from its own filing calendar.
Last, forgetting the paper trail. The CRA wants business records for six years from the end of the last tax year they relate to, and the U.S. company will have its own retention needs. We didn’t check the IRS side.
If the U.S. company is new, start the file when you form it, not when the first deadline is close.
Where the numbers come from
Form 1120 details come from the IRS page about the form. The T2 dates, T1134 timing, record keeping and the federal corporate rates come from Canada Revenue Agency pages and its T2 guide, all read in September 2026. This site has no connection with the IRS, the CRA or any government.
Frequently asked questions
What is Form 1120?
It's the U.S. Corporation Income Tax Return that domestic U.S. corporations file with the IRS.
When is Form 1120 due?
On the 15th day of the fourth month after the tax year ends, which is April 15 for a calendar year company.
Can I get more time to file?
Yes. A corporation can request an extension with Form 7004 before the deadline.
Does a Canadian corporation file Form 1120?
Not for itself. It files a T2 with the CRA. The IRS points foreign corporations to Form 1120-F, and whether you need it depends on your U.S. activity.
What if my Canadian company owns a U.S. company?
The U.S. company files Form 1120. Your Canadian company files a T2 and reports the foreign affiliate on Form T1134.
- 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.