Updated Checked by the Tax-Services.ca editorial team How we check
Most Ontario residents had until April 30, 2026 to file their 2025 tax return and pay what they owed. If you were self-employed, the filing date moved to June 15, 2026, but the payment date stayed at April 30. The 2026 return dates weren’t on the CRA site yet when this was checked, so treat those as unpublished until the CRA posts them.
What does an Ontario tax return actually include?
There’s no separate Ontario return. You file one federal return (the T1), and the province’s share is worked out on Form ON428 as part of it. Ontario tax is then added to your federal tax on the same notice of assessment, so whatever you owe or get back arrives as one figure, and you never deal with a second provincial bill or a second deadline.
That’s why a single mistake on the federal side, such as a missed slip, changes both bills at once. It also means one filing opens the door to Ontario benefits. You apply for the Ontario Trillium Benefit through your return, on Form ON-BEN, and Ontario’s benefit page says you need to file even if you had no income. How the money arrives depends on the size of the payment. If your 2026 benefit is more than $500, you can choose monthly payments starting in July 2026 or one lump sum in June 2027. If it’s $500 or less, you get a single payment in July 2026.
Which dates and penalties matter?
Missing the date is the costly mistake, so start here. These are the 2025-return figures from the CRA.
| Item | What the CRA says |
|---|---|
| Most people, file and pay | April 30, 2026 |
| Self-employed, file | June 15, 2026 |
| Self-employed, pay | April 30, 2026 |
| First late-filing penalty | 5% of what you owe, then 1% more for every full month late, capped at 12 months |
| Repeat late-filing penalty | 10% of what you owe, then 2% more for every full month late, capped at 20 months |
| Interest on unpaid tax | Compounded daily from the day after the due date |
The repeat penalty applies if you were charged one and asked to file on an earlier return. If a date lands on a weekend or a holiday, the next business day counts.
Can’t pay? File anyway. The CRA states that filing on time avoids the late-filing penalty, and you can sort out the payment afterwards, with interest running in the meantime.
How do you actually file it?
You have three realistic routes. Most people use CRA-certified software and send the return over NETFILE, which the CRA lists on its tax software page. Some hand their slips to a preparer who files for them. A paper return still works too, though it’s the slowest of the three. Whichever you pick, have the same pile ready: every T4, T5 and T4A, receipts for donations, medical costs and child care, RRSP slips, and last year’s notice of assessment. The Ontario part takes care of itself once you’ve entered your province of residence on December 31.
What will an Ontario return look like on $90,000?
We ran a $90,000 salary through the income tax calculator for Ontario with no other claims. Federal tax comes to $11,251.60 and Ontario tax to $5,781.96, so $17,033.55 in all. That’s an average of 18.9%. CPP and EI are extra, at $5,769.52.
Now add a $5,000 RRSP deduction. Taxable income falls, and total tax drops to $15,551.05, so the deduction saves $1,482.50. That’s about 29.65 cents on each dollar, the federal 20.5% plus the Ontario 9.15%. Try your own figure in the RRSP calculator.
The calculator uses a basic set of credits and leaves out benefits, so your assessed return will differ a little.
Is a refund likely for you?
That comes down to how much your employer held back. Suppose you earn $60,000 in Ontario and $9,000 was withheld during the year. The tax refund calculator puts your tax at $8,320.50, so you’d get back $679.50.
Small refunds are common at tax time, and they don’t mean you did anything clever. A big one only means you lent the government money for a year, interest free, while your own bills waited. If you want to see what tuition, medical costs or donations add, the tax credits calculator shows the federal side. It doesn’t include Ontario’s own credit amounts, so your true saving is somewhat higher.
What if you realise you got it wrong after filing?
It happens to plenty of people. You find a slip in a coat pocket in June, or a receipt turns up in a drawer. You don’t need to panic and you don’t need to refile from scratch. The CRA lets you ask for a change to a return you’ve already sent, through your CRA account or by mail, and it’s far better to fix it yourself than to wait for the CRA to notice. Keep a note of what you changed and why, because the reassessment will arrive as a new notice.
What trips people up when they file?
A few slips show up again and again.
- Forgetting a slip, such as a T5 for interest or a T4A for side income, which the CRA already has on file.
- Assuming that the extended June date for self-employed people also delays payment. It doesn’t.
- Skipping the return because you earned little. You lose benefit payments like the Ontario Trillium Benefit.
- Claiming an amount without receipts. Keep them in case the CRA asks.
Also, gross negligence is different from an honest error. The CRA’s penalty for knowingly or recklessly making a false statement is the greater of $100 or half the tax you understated. An honest mistake you fix quickly is a different matter.
Where the numbers come from
Dates and penalties are from the Canada Revenue Agency‘s pages for the 2025 tax return, last updated in January 2026. Ontario benefit details are from the Ontario government’s Trillium Benefit page and the CRA’s Ontario tax information. Calculator figures use the 2026 federal and Ontario rates held in our data files, checked against government pages in September 2026. This site isn’t connected to the CRA or the Government of Ontario.
Frequently asked questions
Do I file a separate Ontario tax return?
No. You file one federal T1 return, and Ontario tax is worked out on Form ON428 as part of it.
When was the deadline for the 2025 return?
April 30, 2026 for most people, and June 15, 2026 for the self-employed. Any balance owing was still due April 30. We couldn't find 2026 return dates on the CRA site yet.
What is the penalty for filing late?
The CRA charges 5% of what you owe plus 1% for each full month you're late, capped at 12 months. A repeat penalty is 10% plus 2% a month, capped at 20 months.
Do I need to file if I had no income?
Yes, if you want the Ontario Trillium Benefit. The CRA says you apply through your return with Form ON-BEN, even with no income to report.
How much does a $5,000 RRSP deduction save in Ontario?
On a $90,000 salary it saves $1,482.50, according to our income tax calculator. That's the combined 20.5% federal and 9.15% Ontario steps.
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