Missing even one Canadian tax deadline can result in hundreds—or even thousands—of dollars in penalties. What makes it even more challenging is that most business owners are aware of only a fraction of the dates they’re actually responsible for.
Many Canadians believe taxes come down to one simple date: April 30.
But in reality, that’s just one of many deadlines.
There are separate dates for instalments, GST/HST, payroll, corporate filings, sole proprietorship reporting, RRSP contributions, and more. And each category has its own set of rules, exceptions, and “weekend extensions” that can trip up even experienced business owners.
As accountants who work with individuals, sole proprietors, and corporations across Canada, we see the stress, penalties, and cash-flow issues that arise when deadlines are misunderstood or missed. That’s why we created this in-depth guide—to help you stay informed, compliant, and in control.
To make things easy, you can also download our 2026 Tax Deadline Calendar & Cheat Sheet, which puts every important date into one simplified visual.
Why Tax Deadlines Are So Complicated
Canada has different filing and payment rules depending on:
whether you’re an employee, self-employed, or incorporated
whether you collect GST/HST (and how often you file)
your corporate fiscal year-end
whether you have payroll
whether you owed more than $3,000 last year
This article breaks down what you need to know for 2026, organized into:
Personal tax deadlines
Sole proprietorship deadlines
Corporate tax deadlines
A real-life example: Jim & Mary’s tax calendar
Personal Tax Deadlines for 2026
Personal tax filing is the simplest place to start—but even here, many Canadians miss important dates.
April 30, 2026 – T1 Filing + Payment Deadline
For most individuals, your T1 personal income tax return and any taxes owing must be filed and paid by April 30.
Self-Employed Individuals Get a Filing Extension
If you or your spouse/common-law partner has self-employment income, your filing deadline is extended:
Filing deadline: June 15, 2026
Payment deadline: Still April 30, 2026
Remember: you must pay by April 30, even though you can file in June.
Quarterly Tax Instalments
If you owed more than $3,000 last year (combined federal/provincial), you may be required to pay instalments:
March 16, 2026 (moved from March 15 because it’s a Sunday)
June 15, 2026
September 15, 2026
December 15, 2026
RRSP Contribution Deadline
March 2, 2026 (extended because March 1 is a Sunday)
Contributions made by this date can be applied to your 2025 tax year.
Charitable Donation Deadline
December 31, 2025
All donations must be made by year-end to qualify for the 2025 return.
Sole Proprietorship Tax Deadlines
Sole proprietors often struggle the most because they follow two separate timelines:
Income tax deadlines (which align with personal taxes)
GST/HST deadlines, which depend on revenue and filing frequency
Here’s what to track.
Income Tax (T1) Filing Rules for Sole Proprietors
Filing deadline: June 15, 2026
Payment deadline: April 30, 2026
Business income is reported on Form T2125 within the personal return.
Income Tax Instalments
Instalment rules are the same as personal instalments:
March 16, June 15, September 15, December 15
GST/HST Filing & Payment Rules
Your filing frequency depends on the previous year’s revenue:
Monthly or Quarterly Filers
Returns and payments are due one month after the period ends.
Example:
January 2026 return → Due February 29, 2026
Annual Filers (revenue under $1.5M)
Payment due: April 30, 2026
Return due: June 15, 2026
That means you pay before filing—the same quirky rule as income taxes.
GST/HST Instalments
Required if your net GST/HST owing exceeded $3,000 in the prior year.
For sole proprietors with a calendar year-end, 2026 instalments are due:
April 30
July 31
November 2 (October 31 is a Saturday)
January 31, 2027
Provincial Sales Taxes
Depending on your province:
Québec: QST follows the same frequency as GST/HST
BC, Saskatchewan, Manitoba: PST/RST filings are typically due the last day of the month after the reporting period
T4/T4A Slips for Employees/Subcontractors
Due March 2, 2026 (Feb 28 is a Saturday)
Corporate Tax Deadlines
Corporations follow a completely different set of rules that vary based on their chosen fiscal year-end, size, and GST/HST obligations.
T2 Corporate Income Tax Return
Due 6 months after fiscal year-end.
Examples:
Dec 31, 2025 year-end → June 30, 2026 filing deadline
Mar 31, 2026 year-end → September 30, 2026 filing deadline
Weekend rule applies: if the deadline falls on a weekend/holiday, it moves to the next business day.
Corporate Tax Payment Deadline
Payment is due 2 or 3 months after year-end, depending on whether you qualify as a small business:
3 months: Most CCPCs with taxable income under $500,000
2 months: Larger or non-qualifying corporations
Examples:
Small business with Dec 31 year-end → pay by March 31, 2026
Non-qualifying corporation → pay by February 28, 2026
Corporate Tax Instalments
Monthly instalments for most corporations
Quarterly instalments available for eligible small corporations
For a Dec 31 year-end, quarterly instalments are due:
Mar 31, Jun 30, Sep 30, Dec 31
GST/HST for Corporations
Monthly or Quarterly Filers
Filing & payment: one month after period end
Annual Filers
Filing & payment: three months after fiscal year-end
(This is different from sole proprietors.)
Corporate GST/HST Instalments
If net GST/HST payable exceeded $3,000:
April 30, July 31, November 2, January 31, 2027 (for Dec 31 year-end)
T4 and T4A Filing
Due March 2, 2026
Payroll Remittances
Most corporations remit monthly:
Due the 15th of the following month
Frequent remitters may have semi-monthly or accelerated schedules.
Real-Life Example: Jim & Mary’s 2026 Tax Calendar
To make these rules easier to visualize, let’s look at a real-world couple.
Scenario
Jim owns a corporation with a November 30 year-end, 15 employees, and two subcontractors.
Mary operates a sole proprietorship earning $300,000 annually.
Both collect GST/HST.
Both owed more than $3,000 in income tax last year.
Only Mary contributes to her RRSP.
They make charitable donations together.
How Their 2026 Deadlines Look
Personal Deadlines (Both)
Dec 31, 2025 – Last day for charitable donations
Mar 2, 2026 – RRSP deadline (Mary only) + 1st instalment
Apr 30, 2026 – Personal tax payment deadline
Jun 15, 2026 – Personal filing deadline (extended because Mary is self-employed)
Sep 15 & Dec 15 – Final instalments
Mary’s Sole Proprietorship Deadlines
Apr 30, 2026 – GST/HST payment (annual filer)
Jun 15, 2026 – GST/HST return due
Quarterly GST/HST instalments (if required): Apr 30, Jul 31, Nov 2, Jan 31/2027
Mar 2, 2026 – T4/T4A deadline if she pays contractors
Jim’s Corporation Deadlines
Mar 2, 2026 – Corporate tax payment (3 months after Nov 30 year-end, adjusted for weekend)
May 31, 2026 – T2 filing
Quarterly GST/HST filings/payments: Mar 2, May 31, Aug 31, Nov 30
Monthly payroll remittances: 15th of the following month
Mar 2, 2026 – T4/T4A slips due
When mapped out visually, it becomes clear why business owners feel overwhelmed—deadlines occur throughout the entire year, not just in April.
Why Staying Organized Matters
Missing a deadline can result in:
Late-filing penalties
Interest on unpaid tax balances
Cash-flow disruption
CRA reviews/audits
Payroll or GST/HST non-compliance
For many business owners, the challenge isn’t the taxes themselves—it’s keeping track of the moving pieces.
A strong accounting team should help you stay ahead of these dates, plan your cash flow, and avoid unnecessary stress. But even if you have an accountant, being personally informed puts you in a stronger position to make smart decisions.
Download the 2026 Tax Deadline Calendar
Because there are so many dates to track, we’ve created a 2026 Tax Deadlines Cheat Sheet — a clean, simple, visual calendar that maps every important deadline for:
Employees
Sole proprietors
Corporations
GST/HST filers
Payroll remitters
Instalment payers
If you have questions or want guidance about your specific tax situation, our team is here to help.