Understanding corporate tax rates is essential for any business operating in Ontario. With both federal and provincial tax rates to consider, navigating the tax landscape can feel overwhelming. However, having a clear grasp of these rates and how they apply to your business can help you plan effectively, minimize liabilities, and maximize profits. In this blog, we’ll break down the corporate tax rates in Ontario, explain key deductions and credits, and provide tips to ensure your business stays compliant and financially healthy.
Ontario Corporate Tax Rates
Corporate taxes are levied at two levels in Canada: Federal and Provincial. Here’s how it works for businesses in Ontario:
Federal Corporate Tax Rate:
- The Small Business Deduction (SBD) Rate is 9% on the first $500,000 of active business income.
- The General Corporate Tax Rate is 15% on income above the SBD threshold.
Ontario Provincial Corporate Tax Rate:
- The Small Business Deduction (SBD) Rate is 3.2% on the first $500,000 of active business income.
- The General Corporate Tax Rate is 11.5% on income above the SBD threshold.
Combined Tax Rates in Ontario:
- Small Businesses: 12.2% (9% federal + 3.2% provincial).
- General Corporations: 26.5% (15% federal + 11.5% provincial).
These rates make Ontario an attractive place for businesses, especially small businesses, which benefit from lower tax rates on their first $500,000 of income.
Key Deductions and Credits
The Small Business Deduction (SBD) is one of the most significant tax breaks for CCPCs ( Canadian-controlled private corporations). This deduction reduces the tax rate on the first $500,000 of active business income.
Another valuable incentive is the Scientific Research and Experimental Development (SR&ED) tax credit, encourages a business to invest in innovation by offering tax relief for eligible R&D expenses.
In Ontario, the Ontario Innovation Tax Credit (OITC) offers additional support for small and medium-sized businesses engaged in research and development. Additionally, businesses can claim the Capital Cost Allowance (CCA), which allows them to deduct the cost of capital assets, such as equipment and machinery, over time.
By leveraging these deductions and credits, businesses can significantly lower their taxable income and improve their ultimate outcome.

Tips for Managing Corporate Taxes in Ontario
Effectively managing corporate taxes requires careful planning and attention to detail. Start by working with a tax professional to forecast your tax liabilities and identify opportunities to minimize your tax burden. Accurate and organized financial records ensure compliance and simplify the filing process.
Be sure to file your T2 corporate tax return on time—within six months of your fiscal year-end—to avoid penalties and interest charges. Additionally, explore Ontario-specific programs, such as the Ontario Small Business Support Grant or the Regional Opportunities Investment Tax Credit, which can provide financial relief and incentives for businesses operating in certain regions. By staying proactive and informed, you can confidently navigate corporate taxation’s complexities.
Common Mistakes to Avoid
Even small mistakes can lead to significant consequences when it comes to corporate taxes. One standard error is missing filing deadlines, which can result in hefty penalties and interest charges.
Another pitfall is overlooking eligible deductions, such as the Small Business Deduction or SR&ED credits, which can unnecessarily increase your tax bill. Miscalculating income or failing to report it accurately can trigger audits or reassessments by the Canada Revenue Agency (CRA).
It is imperative to double-check your calculations, maintain thorough records, and consult a tax professional if you’re unsure about any aspect of your tax obligations. Taking these precautions can save your business time, money, and stress in the long run.
Navigating corporate tax rates in Ontario doesn’t have to be complicated. By understanding the federal and provincial tax structures, leveraging deductions and credits, and staying compliant, your business can thrive while minimizing its tax burden.
If you’re unsure about your tax obligations, consider consulting A.M.I. CPA Professional Corporation to ensure your business is on the right track. Stay informed, plan strategically, and make the most of Ontario’s business-friendly tax environment!