Canadian Tax Deadlines 2026: Every Date That Matters for Ottawa Filers

Missing a CRA deadline is one of the most expensive mistakes a Canadian taxpayer can make. Late-filing penalties start at five percent of the balance owing and compound monthly after that. For Ottawa filers juggling employment income, self-employment side projects, or rental properties, keeping track of every date can feel like a full-time job.

This guide lays out every deadline that matters for the 2026 tax year so you can plan ahead and avoid surprises.

TFSA Contribution Room Reset — January 1, 2026

Your Tax-Free Savings Account contribution room resets at the start of each calendar year. For 2026, the annual TFSA limit is indexed to inflation and announced by the Department of Finance in late 2025. Any unused room from previous years carries forward indefinitely.

If you over-contributed in a prior year, the penalty is one percent per month on the excess amount. Review your My Account on the CRA website in January to confirm your available room before making new contributions.

RRSP Contribution Deadline — March 2, 2026

To claim RRSP deductions on your 2025 tax return, contributions must be made by March 2, 2026 (60 days after the end of the calendar year). Your deduction limit is 18 percent of your 2024 earned income, up to the annual maximum, minus any pension adjustment.

This is the single most impactful tax-planning deadline for most employed Canadians. An RRSP contribution reduces your taxable income dollar for dollar, which can shift you into a lower marginal bracket.

T1 Filing Deadline — April 30, 2026

If you are employed or receive pension income, your personal tax return (T1) is due by April 30. This is also the balance-due date — any taxes you owe must be paid by this date to avoid interest charges.

The CRA charges compound daily interest on unpaid balances starting May 1. The prescribed interest rate is set quarterly, and recent years have seen rates climb alongside the Bank of Canada's policy rate.

Late-Filing Penalties

If you owe taxes and file after April 30, the CRA applies:

• Initial penalty: 5% of the balance owing
• Monthly addition: 1% per month, up to 12 months (maximum 17% total)
• Repeat offenders: If you were penalized in any of the three preceding years, the penalty doubles to 10% plus 2% per month for up to 20 months (maximum 50%)

Even if you cannot pay the full amount, file on time. Filing by the deadline avoids the late-filing penalty entirely — you will still owe interest on the unpaid balance, but the penalty is the larger cost.

Self-Employed Filing Deadline — June 15, 2026

If you, or your spouse or common-law partner, earned self-employment income in 2025, the filing deadline extends to June 15, 2026. However — and this catches many people off guard — the payment deadline is still April 30.

That means if you owe money and wait until June to file, you will have already accumulated six weeks of interest by the time the CRA processes your return. The best approach for self-employed filers is to estimate your balance owing, pay by April 30, and then file the completed return before June 15.

Quarterly Instalment Dates

If the CRA expects you to owe more than $3,000 in net tax for 2026 (or more than $1,800 if you are a resident of Quebec), you may be required to make quarterly instalment payments. The due dates are:

• March 15, 2026
• June 15, 2026
• September 15, 2026
• December 15, 2026

The CRA sends instalment reminders in February and August, but the obligation exists whether or not you receive a notice. You can calculate instalments using one of three methods:

1. No-calculation method: Pay the amounts shown on your CRA instalment reminder
2. Prior-year method: Base each payment on your 2025 tax owing, divided by four
3. Current-year method: Estimate your 2026 tax and divide by four

If you underpay, the CRA charges instalment interest. If you overpay, the excess is applied to your final balance. For Ottawa residents with fluctuating self-employment income, getting these estimates right can save hundreds in interest charges. Our tax compliance services include instalment calculation and planning.

Other Dates Worth Noting

Trust Returns (T3) — March 31, 2026

If you are a trustee of a testamentary or inter vivos trust, the T3 return and any balance owing are due 90 days after the trust's tax year-end. For trusts with a December 31 year-end, that means March 31.

Partnership Information Returns — March 31, 2026

Partnerships with a December 31 fiscal year-end must file their T5013 information return by March 31. Individual partners still report their share of partnership income on their personal T1.

Objections and Appeals

If you disagree with a CRA assessment, you have 90 days from the date on the notice of assessment to file a formal objection. Missing this window severely limits your options.

How to Avoid Missing a Deadline

The simplest strategy: work with a professional who manages the calendar for you. When you file with Alta, we track every relevant date — RRSP deadlines, instalment payments, and filing windows — and send reminders before each one arrives.

For Ottawa filers with straightforward returns, the April 30 deadline is the one to circle. For self-employed taxpayers and those with investment or rental income, multiple deadlines apply throughout the year, and a missed instalment can trigger interest before you even realize you owe it.

If you have already missed a deadline, it is not too late to limit the damage. Filing as soon as possible stops the monthly penalty from growing, and the CRA's Voluntary Disclosures Program may provide relief in some circumstances. You can also request a T1 adjustment to recover credits from prior years.

Ready to get ahead of the calendar?