Corporate Tax Rates in Ontario

Canadian corporations pay income tax at two levels: federal (administered by the Canada Revenue Agency under the Income Tax Act, R.S.C. 1985, c. 1 (5th Supp.)) and provincial (Ontario's portion, administered through a coordinated system). The rates are added together to determine the corporation's total tax liability.

The combined rates (as of 2025/2026 tax years):

| Type of Income | Federal Rate | Ontario Rate | Combined Rate | |---|---|---|---| | Active business income (CCPC with SBD) | 9% | 3.2% | 12.2% | | Active business income (no SBD) | 15% | 11.5% | 26.5% | | Investment income (CCPC — RDTOH) | ~38.67%* | ~11.5% | ~50.17% | | Capital gains (CCPC) | ~19.33%* | ~5.75% | ~25.08% |

*Investment income rates include a refundable tax component (RDTOH/GRIP) that is partially recovered when dividends are paid. The effective rates on investment income in a corporation are deliberately high to approximate personal tax rates and prevent income 'parking.'

Why Ontario rates differ from other provinces: Each province sets its own corporate tax rate. Ontario's general rate (11.5%) and small business rate (3.2%) are Ontario-specific. Alberta has no provincial sales tax and lower corporate rates; Quebec and British Columbia have their own rate structures. National corporate planning must account for these differences.

The small business deduction is the most important tax rate reduction available to Ontario small businesses operating through corporations. It reduces the federal corporate tax rate from 15% to 9% on the first $500,000 of 'active business income' earned by a qualifying Canadian-Controlled Private Corporation (CCPC).

What is a CCPC? A Canadian-Controlled Private Corporation (ITA s. 125) is a private corporation (not publicly traded) that is not controlled by non-residents or by public corporations. Most small Ontario businesses will qualify as CCPCs provided: - The corporation is incorporated in Canada - Non-residents do not hold more than 50% of the voting shares - The corporation is not publicly traded

The $500,000 business limit: The SBD applies to the first $500,000 of 'active business income' earned in Canada. Active business income is generally income from a business that is not a 'specified investment business' (whose principal purpose is earning income from property) or a 'personal services business' (where a corporation provides services through an incorporated employee — see the entry on Independent Contractor vs. Corporation).

The passive income grind on the SBD: Under ITA s. 125(5.1), the $500,000 business limit is reduced when a corporation earns more than $50,000 in 'adjusted aggregate investment income' (AAII — investment income net of capital losses) in the prior year. The business limit is reduced by $5 for every $1 of AAII above $50,000. When AAII reaches $150,000, the business limit is fully eliminated and the SBD is no longer available.

Example of the passive income grind: An Ontario software company earns $350,000 in active business income and $80,000 in investment income (dividends, interest, crypto gains). The $80,000 exceeds the $50,000 threshold by $30,000. The business limit is reduced by $150,000 (5 × $30,000). The SBD is now available only on $350,000 of active income (the full $350,000 is within the reduced $350,000 limit, so no SBD is lost in this example — but if active income were $450,000 and AAII were $120,000, the reduction of $350,000 would eliminate $350,000 of SBD access).

The distinction between active business income (taxed at 12.2% with the SBD) and passive investment income (taxed at ~50.17% before refunds) is critical for Ontario corporations.

Active business income includes: - Revenue from providing goods or services in the ordinary course of business - Service fees - Manufacturing or sales revenue - Professional fees (subject to professional corporation rules)

Passive investment income includes: - Interest income (bank interest, bond interest) - Rental income (if the corporation is not in the active business of real estate management) - Dividends from portfolio investments (most dividends received from non-connected corporations) - Capital gains from investment portfolio sales

Why passive income is taxed at ~50% in a corporation: The high rate on passive investment income inside a corporation is deliberately designed to 'integrate' with personal tax rates. The CRA's intent is that earning passive income inside a corporation should not provide a permanent tax advantage over earning it personally. The mechanism for this integration is the Refundable Dividend Tax on Hand (RDTOH) account, which allows a portion of corporate tax on investment income to be refunded when the corporation pays dividends to shareholders.

Inter-corporate dividends: Dividends received by one corporation from another Canadian corporation in which it has a significant interest are typically received tax-free under ITA s. 112 (the inter-corporate dividend deduction). This allows a holding company to receive dividends from an operating company without a second layer of corporate tax.

Tax integration is the foundational principle of Canadian corporate tax design: ideally, the combined corporate and personal tax on income earned through a corporation should be approximately equal to the personal tax that would have been paid if the income had been earned directly.

How integration works in theory: When a CCPC earns active business income: 1. Corporate income tax is paid at 12.2% (with SBD in Ontario) 2. The after-tax income is paid to shareholders as dividends 3. Shareholders pay personal tax on the dividends, but receive a dividend tax credit that accounts for the corporate tax already paid 4. The total combined tax should approximate the personal marginal rate

Integration is imperfect in practice: The dividend tax credit mechanism was calibrated against specific corporate tax rates. When the federal corporate tax rate changes, the integration calculation shifts. Ontario-specific rates create additional nuances. As a general rule: - At the lower SBD rate (12.2%), there is a moderate 'deferral advantage' — tax is paid at a lower rate inside the corporation than it would be personally, and personal tax is only paid when dividends are declared - At the general rate (26.5%), the deferral advantage is smaller - The deferral advantage is valuable if retained earnings are reinvested in the business before eventually being paid out as dividends or triggering the Capital Gains Exemption on the sale of qualifying shares

Comparison to personal rates: Ontario's top combined federal/provincial marginal rate on employment or business income is approximately 53.53% (for income above $246,752 in 2025). The 12.2% corporate SBD rate, compared to 53.53% personal, represents a substantial deferral — paying 12.2% now vs. 53.53% if paid personally. However, when the after-tax corporate income is eventually paid to the shareholder as a dividend, the total tax converges toward the personal rate due to the dividend gross-up and tax credit mechanism.

For Ontario business owners deciding between incorporating and operating as a sole proprietor (or partnership), the tax rate comparison is a primary factor.

Personal marginal tax rates in Ontario (2025):

| Income Level | Combined Federal + Ontario Rate | |---|---| | Up to $57,375 | ~20.05% | | $57,375 to $116,550 | ~29.65% | | $116,550 to $158,779 | ~37.91% | | $158,779 to $246,752 | ~43.41% | | Above $246,752 | 53.53% |

Corporate rates (Ontario CCPC): - With SBD: 12.2% on first $500,000 of active business income - Without SBD: 26.5% on active business income

The deferral advantage: A business earning $300,000 of annual profit pays: - As sole proprietor: ~$130,000+ in personal tax (at marginal rates) - As corporation with SBD: ~$36,600 in corporate tax ($300,000 × 12.2%)

The $93,400+ difference is not a permanent savings — it is a deferral. The corporate tax is paid now; personal tax is owed later when the after-tax profits are paid out as dividends. However, the deferral allows the retained earnings to be reinvested in the business, generating compound growth on the pre-personal-tax amount.

When the math favours personal over corporate: For businesses with very low retained profits (owners who draw virtually all earnings as salary), the deferral benefit is minimal and the administrative cost of running a corporation (accounting, legal, compliance) may outweigh the benefit. Generally, incorporation for tax purposes starts to make significant sense when consistent annual retained earnings exceed $50,000-$100,000.

Ontario corporations enjoy significant tax rate advantages over individuals on active business income — particularly through the small business deduction, which reduces the combined rate to 12.2% on the first $500,000 of CCPC active business income. However, the passive income grind, the investment income integration mechanism, and the eventual personal tax on dividends mean that incorporation is not a tax elimination strategy but a tax deferral strategy.

For most Ontario small businesses earning consistent annual profits above $50,000-$100,000 that are not immediately needed for personal expenses, incorporation and retention of earnings inside the corporation provides a meaningful tax deferral advantage that accelerates business growth.