Missed deadlines are the most avoidable cost in small business. The penalties aren't huge per slip, but they stack — a late return here, a missed remittance there, interest compounding daily — and all of it is the kind of money you light on fire for nothing. The fix is almost embarrassingly simple: know the dates, and put them in your calendar before the year gets busy.
Below is the 2026 calendar for a typical Canadian small business. Some dates are fixed for everyone (personal filing, RRSP); others — corporate and GST/HST — depend on your fiscal year-end and filing frequency, so I'll show you how to calculate yours.
- March 2, 2026 — RRSP contribution deadline (2025 tax year) and the deadline to file T4/T5 slips (the last day of February falls on a weekend, so it shifts to the next business day).
- April 30, 2026 — file & pay your 2025 personal taxes. Even self-employed people must pay by this date.
- June 15, 2026 — filing deadline if you (or your spouse) are self-employed — but any balance was still due April 30.
- Corporate & GST/HST dates float with your year-end and filing frequency — see the sections below to find yours.
- The trap: the filing deadline and the payment deadline are often different dates. Interest starts on the payment date, even if your return isn't due yet.
Read on for the full calendar, how to calculate your corporate and sales-tax dates, the filing-vs-payment trap, and a real-world example.
The deadlines that are the same for everyone
These don't depend on your business structure — every individual taxpayer shares them. When a deadline lands on a Saturday, Sunday, or public holiday, the CRA treats the next business day as on time, which is why several 2026 dates shift.
- March 2, 2026 — RRSP contribution deadline for the 2025 tax year. (The usual March 1 falls on a Sunday, so it moves to March 2.)
- March 2, 2026 — T4 and T5 information returns due. The deadline is the last day of February; February 28, 2026 is a Saturday, so it shifts to Monday, March 2. This covers T4s for employees and T5s for dividends you paid.
- April 30, 2026 — file and pay 2025 personal income tax. This is also the payment deadline for self-employed individuals, even though they get more time to file.
- June 15, 2026 — personal filing deadline if you or your spouse/common-law partner ran a business in 2025. Any balance owing was still due April 30 to avoid interest.
Source: CRA, "Due dates and payment dates" (individuals) and "Important dates for RRSP, RRIF…" — personal returns are due April 30; self-employed individuals have until June 15 to file but must pay by April 30; the RRSP deadline is 60 days into the year; T4/T5 returns are due the last day of February, with weekend deadlines moving to the next business day.
Corporate (T2): the dates that float with your year-end
A corporation doesn't use the calendar year — it uses its fiscal year-end, which you chose when you incorporated. Two separate clocks run from that date, and confusing them is the single most common corporate mistake:
- Filing (the T2 return): within 6 months of your fiscal year-end.
- Paying the balance owing: within 2 months of your year-end — or 3 months if you're a Canadian-controlled private corporation (CCPC) that claimed the small business deduction and meets the conditions.
Source: CRA, "Balance-due day" (corporations) — the balance of corporate tax is due two months after the end of the tax year, extended to three months for a CCPC claiming the small business deduction that meets the stated conditions; the T2 return itself is due six months after year-end.
The money is due three months before the paperwork. Pay by March 31 even though you have until June 30 to file — otherwise interest runs from April 1. For a non-CCPC, the balance would be due February 28 (2 months).
To find yours: take your year-end, add 2 or 3 months for payment, and 6 months for filing. (New to this? See Should you incorporate? for the bigger picture.)
GST/HST: it depends on your filing frequency
Your GST/HST deadlines hinge on how often you file, which is set by your revenue (and your own election):
| Filing frequency | Return + payment due |
|---|---|
| Monthly | One month after the end of the reporting month |
| Quarterly | One month after the end of the quarter |
| Annual (most corporations) | Three months after fiscal year-end |
| Annual (sole proprietor, Dec 31 year-end) | File June 15 · pay April 30 |
Source: CRA, "Reporting requirements and deadlines" (GST/HST) — monthly and quarterly filers must file and remit one month after the reporting period; annual filers generally have three months after their fiscal year-end, except individuals with a December 31 fiscal year-end (and business income), who file by June 15 and pay by April 30.
For annual GST/HST filers, note the same April-30-vs-June-15 split as personal tax: a sole proprietor pays by April 30 but files by June 15. (If you're not registered yet, here's when you have to register, and how to actually file the return.)
Payroll remittances: monthly, all year
If you run payroll, source deductions (income tax, CPP, EI) you withhold are remitted to the CRA on a recurring schedule. For most small and new employers — "regular remitters" — the deadline is the 15th day of the month after you paid your employees. Larger payrolls remit more often.
Source: CRA, "When to remit (pay)" — regular remitters must remit source deductions by the 15th of the month following the month the deductions were withheld; remitter type depends on your average monthly withholding amount.
This is the deadline owners forget most, because it repeats twelve times a year and never makes headlines. Miss it and the penalty can reach 10% of the amount — more for repeat lateness. (Setting up payroll for the first time? See payroll without incorporating.)
Instalments: paying tax before the year is over
Once your tax owing passes a threshold, the CRA stops waiting until year-end and asks for quarterly instalments during the year. For individuals, the 2026 instalment due dates are March 15, June 15, September 15, and December 15. Corporations pay monthly or quarterly instalments based on their own year-end. Miss instalments and you'll owe instalment interest — and possibly a penalty — even if you pay the full balance on time.
Source: CRA — individuals who have to pay by instalments use the quarterly dates of March 15, June 15, September 15, and December 15; corporations pay monthly or quarterly instalments depending on eligibility.
Filing date ≠ payment date
If there's one idea to burn into memory, it's this: the deadline to file a return and the deadline to pay the tax are frequently different days — and interest always runs from the payment date. It shows up everywhere on this calendar:
- Self-employed: file by June 15, but pay by April 30.
- Corporations: file within 6 months, but pay within 2–3 months.
- Annual GST/HST (sole prop): file by June 15, but pay by April 30.
"I have until June to deal with it" is true for the paperwork and false for the money. Owners who conflate the two get a clean filing and a surprise interest bill.
Tanya thought she had until June
Meet Tanya, who runs Birchbark Outfitters, an incorporated outdoor-gear shop in Thunder Bay, Ontario, with a December 31 year-end. Her first year incorporated, she had a great season and owed about $14,000 in corporate tax. She knew her T2 was due "six months after year-end" — June 30 — so she planned to handle everything that spring, taxes included.
What she didn't know: as an eligible CCPC, her payment was due three months after year-end — March 31, not June 30. She filed and paid in late June, comfortably before the filing deadline, and then got a notice charging interest on the $14,000 from April 1 onward.
She wasn't late filing — she was three months late paying, and never knew the two deadlines were different.
The interest wasn't catastrophic, but it was pure waste — money for nothing, on a bill she had the cash to cover in March. The fix was simply knowing the date.
What should have happened
The moment Tanya incorporated, both clocks should have gone in her calendar: pay by March 31, file by June 30. If cash is tight at the payment date, you can still pay what you can to stop interest accruing on that portion. Either way, the mistake is never knowing the payment deadline exists — and it's entirely preventable.
The five-minute habit that prevents all of this
Every deadline above is avoidable with one short session. Sit down once, map your specific dates, and set calendar reminders two weeks ahead of each:
- March 2, 2026 — RRSP + T4/T5 slips.
- April 30, 2026 — personal file & pay; self-employed/sole-prop GST/HST payment.
- June 15, 2026 — self-employed personal filing; annual GST/HST filing (sole prop).
- Your corporate dates — year-end + 2–3 months (pay), + 6 months (file).
- Your GST/HST dates — based on your filing frequency.
- The 15th of each month — payroll remittance, if you have employees.
- Mar 15 / Jun 15 / Sep 15 / Dec 15 — instalments, if you're required to pay them.
Want these dates handled for you?
Keeping clean monthly books means every one of these deadlines is met without you watching the calendar. A 20-minute call is enough to map your specific dates and figure out what to hand off.
Book a Free 20-Minute CallThis article is for informational purposes only and does not constitute tax, legal, or accounting advice. Dates are for the 2026 calendar year and the 2025 tax year; deadlines shift for weekends and holidays, and your corporate and GST/HST dates depend on your fiscal year-end and filing frequency. This calendar is updated annually — confirm your specific dates with the CRA or a qualified professional.
Primary sources, linked so you can confirm your own dates. Government links open on official Government of Canada websites.
- CRA — Due dates and payment dates (individuals) (April 30 / June 15)
- CRA — Important dates for RRSPs, HBP, LLP, FHSAs and more (RRSP contribution deadline)
- CRA — Balance-due day (corporations) (the 2-month / 3-month payment rule)
- CRA — Reporting requirements and deadlines (GST/HST)
- CRA — When to remit (pay) source deductions (the 15th-of-the-month rule)
- CRA — 2026 tax deadlines for Canadian businesses and self-employed individuals
- Related reading: How to File Your GST/HST Return, Payroll Without Incorporating, and Should You Incorporate?
Rodney Maiato is the founder of CDL Accounting Solutions, a remote bookkeeping practice helping Canadian incorporated small businesses keep clean, audit-ready books without the year-end scramble. He brings 15+ years in accounting — from junior accountant to assistant controller, where he managed a team of 7 and oversaw the books of 25+ companies, plus payroll for 100+ employees across several provinces — and is a Payroll Compliance Professional (PCP) Candidate with the National Payroll Institute. He also builds the automation behind CDL, including its text-in receipt intake system.