First-Year Tax Calendar for Canadian Founders

Who this guide is for

First-year founders — sole proprietors and freshly incorporated companies alike — who want to know exactly which dates matter and stop discovering deadlines after they've passed.

Missing a tax deadline rarely means one clean penalty; it means interest compounding quietly, sometimes for months, before you notice. The fix is simply seeing the calendar in advance. The fixed examples below are 2026 deadlines for the 2025 tax year. The rules repeat every year, but the exact dates move when weekends or holidays intervene, so confirm the current ones with the CRA.

The distinction that causes most of the pain

Burn this in: the deadline to file a return and the deadline to pay the tax are not the same date, and the payment deadline is usually earlier. You can file perfectly on time and still rack up interest because you paid late. The CRA charges compound daily interest from the payment due date — not the filing date — so "I filed on time" is no protection if a balance went unpaid.

The practical move, every year: estimate what you owe and pay it by the payment deadline, even before your return is finished. Overpaying gets refunded; underpaying costs interest. Finishing the paperwork can come later, within the filing window.

The dates that are the same every year

If you're a sole proprietor (or report business income personally), these calendar dates are fixed and don't depend on a fiscal year-end:

• April 30 — pay your personal balance owing. This applies to everyone, including the self-employed. In 2026 that's April 30, 2026. Interest starts the next day on anything unpaid.
• June 15 — file your return if you're self-employed. You (and your spouse or common-law partner) get the later filing date — June 15, 2026 — but, again, any tax was due April 30.
• Early March — RRSP contribution deadline for contributions you want to count against the prior year (the first 60 days). For 2026 that date is March 2, 2026.
• Quarterly instalments — March 15, June 15, September 15, December 15 — but only if you're required to pay them (see year-one note below).

Corporate dates move with your fiscal year-end

A corporation's deadlines aren't calendar-fixed; they're measured from your fiscal year-end, which you choose (it needn't be December 31). For a year-end on the last day of a month, the deadlines fall on month-ends; otherwise they fall on the same day of the relevant later month.

• File the T2 return: within 6 months of year-end. A December 31 year-end means a June 30 filing deadline. Every corporation must file, even with no income, even if inactive.
• Pay the balance: within 2 months of year-end for most corporations (the last day of February for a December 31 year-end). Eligible CCPCs get 3 months (March 31 for a December 31 year-end).
• The 3-month payment extension applies only if the corporation was a CCPC throughout the year, claimed the small business deduction (this year or last), and — with associated corporations — has taxable capital under $10 million. Miss any one and the 2-month rule applies.
• Corporate instalments are normally monthly (eligible small CCPCs may pay quarterly), but not in the first year, and not if total tax is $3,000 or less.

If the calculated corporate payment or filing date falls on a weekend or CRA-recognized holiday, the next business day rule applies: for a December 31, 2025 year-end, the 2-month payment date is February 28, 2026, a Saturday, so payment received the next business day is on time.

So the corporate dates can't sit on a fixed January–December ribbon: a company with a September 30 year-end pays by late November and files by late March. Anchor them to your year-end.

GST/HST: timing depends on your reporting period

If you're registered for GST/HST, your filing and payment dates follow your assigned reporting period (annual, quarterly, or monthly — see the GST/HST guide):

• Annual filer, individual with a December 31 year-end: your return is due June 15 and any payment is due April 30 — mirroring the personal income-tax dates.
• Annual filer, corporation (and most other annual filers): both the return and payment are due 3 months after the fiscal year-end.
• Quarterly or monthly filers: the return and payment are due one month after the end of each reporting period.

Remember you may have to register before you hit the $30,000 small-supplier threshold or once you cross it, and if you registered voluntarily, the filing obligations start regardless of revenue.

Payroll: monthly remittances and February slips

If you have employees (including yourself, if the corporation pays you a salary), you'll have payroll dates too:

• Remit source deductions (CPP, EI, income tax withheld) on the CRA's schedule. A new/regular remitter generally pays by the 15th of the month after the month you paid wages. Remittances are late from day one if missed, with penalties.
• T4 slips (employment income) and T5 slips (dividends) must be filed with the CRA and given to recipients by the last day of February following the calendar year; if it falls on a weekend, the next business day. For 2025 slips, the due date was March 2, 2026 (February 28, 2026 is a Saturday).

The payroll mechanics and the verified 2026 CPP/EI figures live in the CRA-accounts guide.

The quirks of the first year

• You generally don't pay instalments. Instalments are triggered by tax owing in a prior year. If this is your first year with business income and you did not have prior-year net tax owing above the CRA threshold, you generally will not owe personal tax instalments yet, but a prior year of tax owing can change that, so "first year in business" is not always "first year with instalment risk." New corporations don't have to make instalment payments until their second year, though the first-year tax is still due on the balance-due day. Instalments otherwise begin the following year if your tax crosses the threshold. (Set money aside anyway — that lump sum is real.)
• Your first corporate tax year is often a "short year." It runs from the date of incorporation to your chosen fiscal year-end, which can be less than 12 months (a tax year can't exceed 53 weeks). Your 6-month filing and 2-or-3-month payment deadlines are measured from that first year-end.
• GST/HST registration timing. You may not need to register until you approach or cross $30,000 in revenue — but once you do (or if you register voluntarily), the filing clock starts.
• First filings establish the pattern. Your first return sets your reporting periods and instalment status going forward, so getting it right (ideally with an accountant) pays off for years.

Two common first-year setups

Most founders fall into one of these. Use them as templates, then adjust to your own dates.

Illustrative for a Dec 31 year-end, 2026. Your dates depend on your structure, year-end, GST/HST period, and whether you have payroll — confirm yours with the CRA or an accountant.

The fixed 2026 dates, in one place

What missing a date actually costs

• Late-filing penalty. For both personal and corporate returns, filing late when you owe tax is 5% of the balance plus 1% per month the return is late (up to 12 months) — and more for repeat offences. Filing on time even when you can't pay avoids this penalty entirely.
• Interest on unpaid tax compounds daily from the payment deadline at the CRA's prescribed rate (which changes quarterly). It's charged whether or not you filed on time.
• Instalment interest (and a possible penalty) applies if required instalments are late or short — another reason the year-one instalment break is worth understanding, since it means there's nothing to miss in year one.

When to get help

A simple rule: have an accountant set up your first return — corporate especially — because it locks in your year-end, reporting periods, and instalment status for years, and small first-year mistakes compound. Between filings, the highest-leverage habit is the cheapest: put tax money aside as you earn it, and set calendar reminders two weeks before each date above.

If you're in British Columbia

• Provincial corporate tax is filed with your federal T2. B.C. doesn't run a separate corporate return for most companies — the CRA administers it, so your T2 dates cover it.
• PST has its own calendar if you're registered for it — separate from GST/HST, with its own filing frequency. And note the announced expansion of B.C. PST to certain professional services from October 1, 2026 (covered in the GST/HST guide), which may bring new founders into PST filing.

Checked June 2026. Dates and rules change — confirm current deadlines with the CRA and the B.C. government.

Common mistakes to avoid

Official sources

Dates shift year to year and move on weekends and holidays — confirm the current ones at the CRA.