Missing a CRA deadline is one of the most expensive avoidable mistakes a Canadian small business can make. The filing itself might take an hour. The penalty and compound daily interest that follow a late return can run for years.
This guide lays out the deadlines that actually apply to small businesses in Canada, who each one applies to, and what happens if you miss it. Bookmark it — most of these dates repeat every year.
One rule applies across almost everything below: if a deadline lands on a Saturday, Sunday or a public holiday recognised by the CRA, your return or payment is considered on time if the CRA receives it on the next business day.
Personal and self-employed income tax (T1)
If you run an unincorporated business — a sole proprietorship or a partnership — your business income is reported on your personal return.
- April 30, 2026 — deadline for most individuals to file and pay any balance owing.
- June 15, 2026 — filing deadline if you or your spouse or common-law partner had self-employment income.
The trap here catches new business owners every single year: the June 15 extension applies to filing, not to paying. Any balance owing is still due April 30. File in June if you like, but if you owe money and haven’t paid it by the end of April, interest is already accumulating.
Corporate income tax (T2)
Corporations don’t run on the calendar year unless you choose to. Your deadlines hang off your own fiscal year-end.
- Filing: your T2 return is due six months after the end of your fiscal year. A December 31 year-end means a June 30 filing deadline.
- Payment: the balance owing is generally due two months after year-end — or three months for a Canadian-controlled private corporation claiming the small business deduction, provided it meets the CRA’s conditions.
Notice the gap. You may owe the money months before the return is due. This is why a corporation with messy books gets hurt twice: you can’t estimate the balance, so you underpay, and then interest runs while you sort out the records.
Payroll deadlines
If you have employees, you have three separate obligations: remitting deductions, filing slips, and issuing records of employment.
- Remittances: most new and small employers are regular remitters, meaning source deductions are due by the 15th day of the month following the month you paid your employees. Higher payroll volumes move you into accelerated remitter categories with tighter dates.
- T4 slips and the T4 Summary: due on or before the last day of February for the previous calendar year. Our full walkthrough is here: T4 Slips Explained: Deadlines, Penalties & How to File.
- Records of Employment: issued whenever an employee has an interruption of earnings, not annually.
Payroll penalties are the harshest in the system because the money you remit was never yours — it was withheld from an employee. The CRA treats it that way. If payroll is new to you, start with Payroll Basics for Canadian Employers.
GST/HST deadlines
Your GST/HST filing frequency depends on your annual taxable supplies, and the CRA can assign you a frequency you didn’t pick.
| Filing frequency | Return and payment due |
|---|---|
| Monthly | One month after the end of the reporting period |
| Quarterly | One month after the end of the reporting period |
| Annual (most corporations) | Three months after fiscal year-end |
| Annual (self-employed individual, Dec 31 year-end) | File by June 15, pay by April 30 |
Registration timing matters as much as filing. If you’re not sure whether you’ve crossed the threshold, read GST/HST for Small Businesses: When to Register & How to File.
Instalment payments
Once your tax owing passes the CRA’s threshold, you stop paying in one lump and start paying quarterly instalments. For individuals these generally fall on March 15, June 15, September 15 and December 15. Corporations pay monthly or quarterly instalments depending on their situation.
Instalment interest is charged when you pay late or short — and if that interest gets large enough, the CRA adds an instalment penalty on top.
What late filing actually costs
- Late-filing penalty: 5% of the balance owing, plus 1% for each full month the return is late, to a maximum of 12 months.
- Repeat offence: if the CRA already charged you a late-filing penalty in any of the three previous years and issued a demand to file, the penalty can double to 10% plus 2% per month for up to 20 months.
- Interest: compound daily on unpaid balances, at a rate the CRA sets quarterly.
- Nil returns still count. A GST/HST return with nothing owing is still a required filing.
Rates and thresholds change. Always confirm the current figures on canada.ca before you rely on them for a specific filing.
The real fix isn’t a calendar
Most missed deadlines aren’t caused by forgetting the date. They’re caused by not having the numbers ready when the date arrives. When your bank feeds are reconciled monthly and your receipts are filed as you go, hitting a deadline is a thirty-minute job. When they aren’t, it becomes a two-week scramble — and that’s when things get missed.
If you’re weighing up whether to hand this off, Do I Need a Bookkeeper or an Accountant? explains who handles what.
EverBooks keeps books CRA-ready year-round for businesses across Canada, so filing season is a formality rather than a fire drill. Have a look at our bookkeeping and tax preparation services, or book a free consultation and we’ll map your specific deadlines together.
