Who pays it and where it appears
The premium is worked out on Form ON428, Ontario Tax, as part of your personal return. You pay it if you were a resident of Ontario at the end of the year and the taxable income on line 26000 of your return is more than $20,000. The end of the year is December 31, the date you left Canada if you emigrated, or the date of death on a final return.
The premium is added to your Ontario tax and flows into the Ontario tax amount you report on line 42800. You will not see a separate premium invoice. It simply raises the total income tax payable for the year, which is why it is easy to overlook when you estimate tax from bracket rates alone.
How the amount steps up
On the 2025 form the premium is nothing at $20,000 or less. Between $20,000 and $25,000 it is 6% of the amount over $20,000, reaching $300. It stays at $300 up to $36,000, then climbs to $450 by $38,500, stays at $450 up to $48,000, and rises to $600 by $48,600.
It holds at $600 up to $72,000, rises to $750 by $72,600, holds there up to $200,000, and reaches $900 by $200,600. Above that the premium stays at $900. These figures come from the 2025 form, so check the form for the year you are filing before relying on them.
An illustrative example
Take three people with taxable income of $22,000, $45,000 and $100,000, using the 2025 chart. The first pays 6% of $2,000, which is $120. The second falls in the $38,500 to $48,000 range and pays $450. The third pays $750. These figures are illustrative and ignore every other part of the return.
Credits do not reduce the premium. On Form ON428 the premium is added after the non-refundable credits and the Ontario tax reduction have been applied, so a large medical or donation claim lowers your bracket-based Ontario tax but leaves the premium unchanged. A deduction that lowers taxable income can change the premium only if it moves you across one of the steps.
What to discuss with your accountant
Ask whether the premium is built into your estimate of tax owing, especially if you are self-employed and setting money aside during the year. Bring an estimate of this year’s taxable income, not just your salary or gross revenue, because the chart works from the line 26000 figure.
If your income sits close to a step, ask whether timing a deduction or income item into a different year makes a meaningful difference. For how this sits beside the other Ontario amounts, see the Ontario surtax and the Ontario tax reduction.
Sources & editorial notes
Sources checked October 24, 2026. The examples are illustrative and provide general information. Discuss how the guidance applies to your circumstances with your accountant.
- Ontario tax information for 2025Canada Revenue Agency
- Form ON428, Ontario Tax (2025)Canada Revenue Agency
Rules and guidance can change. Use the current official source and confirm the treatment for your facts. To flag an error, contact Sora.