T1 filing deadline 2026: file and pay April 30, June 15 for business

Every T1 due date for the 2025 and 2026 tax years

For 2025, the CRA's dates are April 30, 2026 to file and pay, and June 15, 2026 to file if you or your spouse or common law partner are self employed canada.ca. The 2026 column applies the same Income Tax Act dates to 2027. As of October 2026 the CRA's filing dates page still covers only the 2025 return.

The dates come from paragraph 150(1)(d) of the Income Tax Act: April 30 of the following year for an individual, or June 15 for an individual who carried on a business (unless its spending was primarily the cost of tax shelter investments) and for anyone who was a cohabiting spouse or common law partner of that individual at any time in the year laws-lois.justice.gc.ca. The June 15 date moves the filing only. The CRA is explicit that a 2025 balance owing had to be paid on or before April 30, 2026 canada.ca. The sole proprietor side, including instalments and the GST/HST annual return, is on our self employed deadline page.

What filing late costs: a worked example

If your client owes tax and files late, the penalty is 5% of the 2025 balance owing plus 1% for each full month late, up to 12 months. A client who was penalized for 2022, 2023 or 2024 and got a demand to file pays 10% plus 2% a month, up to 20 months canada.ca. Interest on the unpaid tax compounds daily from the day after the due date canada.ca, and interest on the penalty runs from the day the return was due under subsection 161(11) laws-lois.justice.gc.ca.

The rate on overdue taxes was 7% for April to June 2026 canada.ca, 7% for July to September canada.ca and is 7% for October to December, as of October 2026 canada.ca.

Worked example: your client owes $5,000 on the 2025 return, due April 30, 2026, and pays it on September 10, 2026. Interest is $5,000 × ((1 + 0.07 ÷ 365)^133 − 1). Four full months have passed since April 30, so the regular penalty is 5% + 4% = 9%.

Filing on time and paying late saved $461.62. For a client caught by the repeat penalty, the same four months cost 10% + 8% = 18%, or $900 before interest. The rate itself is covered on our overdue interest page.

Refund clients and clients who cannot pay

The late filing penalty is a percentage of the balance owing canada.ca, so a client with a refund or a nil balance owes no penalty for filing late. Late still costs them: the CRA warns that filing late can delay benefit and credit payments canada.ca. For a family that includes the Canada child benefit, which needs a return from both spouses every year.

A client who can't pay should still file by the deadline. The CRA's advice is to file on time even if you can't pay, to avoid the late filing penalty canada.ca. Interest still runs on the unpaid balance; a payment arrangement deals with the debt.

Form T1135 is the exception to the no balance logic. It must be filed on or before the due date of the income tax return, even if the return itself isn't required canada.ca, and its penalty doesn't depend on tax owing. The amounts are on our T1135 penalty page.

When a deadline falls on a weekend or holiday

If a due date falls on a Saturday, Sunday or a public holiday the CRA recognizes, the return is on time if the CRA receives it, or it's postmarked, on or before the next business day. A payment is on time if the CRA receives it on the first business day after the due date canada.ca.

None of the 2026 or 2027 T1 dates in the table above lands on a weekend. June 15, 2025 was a Sunday, so 2024 returns from sole proprietors and their spouses were on time on Monday, June 16, 2025.

The same shift shows up in the RRSP deadline. The CRA lists March 2, 2026 as the last day to contribute for 2025 canada.ca, because March 1, 2026 was a Sunday.

Due dates when a client dies

The final return for a deceased client follows the date of death, not the usual April 30 canada.ca.

The prior year return is the trap. When a client dies after October and on or before their filing due date, paragraph 150(1)(b) makes that return due on the later of the normal due date and 6 months after death laws-lois.justice.gc.ca. A client who died on March 10, 2026 without filing for 2025 therefore has a 2025 return due September 10, 2026.

The surviving spouse or common law partner gets the same extended filing date under subparagraph 150(1)(d)(iii) laws-lois.justice.gc.ca, but the CRA says the survivor's own balance must still be paid by April 30, 2026 to avoid interest canada.ca. Returns for earlier years that were already due keep their original deadlines. The final return itself is covered on our final return page, and the optional return is on the rights or things page.