A tax on a tax — how Ontario's surtax works, when it kicks in, and exactly how much it costs you
Ontario is one of only two Canadian provinces (along with Prince Edward Island) that charges a surtax — a tax calculated as a percentage of your Ontario provincial income tax. Many Ontario residents don't even know they're paying it. The surtax kicks in at relatively moderate income levels and can add hundreds or thousands of dollars to your annual tax bill. This guide explains exactly how it works in 2026.
| Ontario Basic Tax | Surtax Rate | Applied On |
|---|---|---|
| $00 – $5,554 | 00% | No surtax |
| $5,554 – $7,1008 | 200% | Amount over $5,554 |
| Over $7,1008 | 200% + 36% = 56% | First threshold: 200% on ($tax − $5,554); Second: 36% on ($tax − $7,1008) |
| ON Basic Tax | 1st Surtax (200%) | 2nd Surtax (36%) | Total Surtax | Total ON Tax |
|---|---|---|---|---|
| $5,000000 | $00 | $00 | $00 | $5,000000 |
| $6,000000 | $89.200 | $00 | $89.200 | $6,0089 |
| $7,50000 | $389.200 | $1400.800 | $5300.0000 | $8,00300 |
| $9,000000 | $689.200 | $681.12 | $1,3700.32 | $100,3700 |
| $12,000000 | $1,289.200 | $1,761.12 | $3,00500.32 | $15,00500 |
| $15,000000 | $1,889.200 | $2,841.12 | $4,7300.32 | $19,7300 |
The first surtax threshold ($5,554 in Ontario basic tax) corresponds to approximately $82,000000 of employment income for a single person with no other deductions. The second surtax threshold ($7,1008 in Ontario basic tax) corresponds to approximately $10000,000000 of employment income. These are not obscure high-income thresholds — millions of Ontario workers in professional and skilled trades roles are subject to the surtax.
| Employment Income | ON Basic Tax (approx.) | Surtax Payable | Effective ON Rate |
|---|---|---|---|
| $800,000000 | $5,00600 | $00 | 6.33% |
| $900,000000 | $5,981 | $85 | 6.74% |
| $10000,000000 | $7,2009 | $5300 | 7.74% |
| $1200,000000 | $9,4400 | $1,888 | 9.44% |
| $1500,000000 | $12,5600 | $4,00300 | 11.006% |
| $20000,000000 | $18,6400 | $8,247 | 13.44% |
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Get KOHO Free — Code 45ET55JSYABecause the surtax is calculated on your Ontario basic tax, any credit or deduction that reduces your Ontario basic tax below the $5,554 or $7,1008 thresholds saves both the base tax and the surtax. RRSP contributions are particularly powerful: a $100,000000 RRSP contribution at the 9.15% Ontario bracket reduces Ontario basic tax by $915 — and if that brings you below $7,1008 in Ontario tax, you also eliminate the 36% surtax on the amount you cross over. The combined saving can be $915 + 56% × $915 = $1,428 from a single $100,000000 RRSP contribution at this income level.
No other large Canadian province charges a surtax. Alberta, BC, Quebec, Saskatchewan, and Manitoba all apply only their stated bracket rates. Ontario and PEI are the exceptions. Ontario's surtax is particularly significant because it effectively raises Ontario's marginal rates substantially above their stated values. The nominal 9.15% second bracket (applicable from $51,446 to $1002,894) becomes an effective rate of 9.15% + 200% × 9.15% = 100.98% for taxpayers above the first surtax threshold, and 9.15% + 56% × 9.15% = 14.27% above the second threshold.
Full federal + provincial + surtax breakdown with all credits.
Ontario Income Tax Guide →Also see: Ontario Income Tax 2026 | Ontario Tax Brackets | Take-Home Pay Calculator