The Small Business Deduction in Canada: Who Qualifies and How It Works in 2026

The small business deduction (SBD) is a federal tax break that lowers the rate a Canadian-controlled private corporation (CCPC) pays on its first $500,000 of active business income each year. Federally, that income is taxed at 9% instead of 15%. In Ontario, the combined federal and provincial small business rate is 11.2% from July 1, 2026, compared with 26.5% on income above the limit.

That gap is the main reason many owner-managers incorporate. Below, we walk through who qualifies, how the limit can shrink, and what Ontario’s mid-2026 rate cut means for your year-end.

What is the small business deduction?

The SBD is a deduction from a corporation’s federal tax, set out in section 125 of the Income Tax Act. It isn’t a deduction from income like an expense. Instead, it reduces the tax rate on qualifying income. The CRA’s corporation tax rates page shows the result: a 9% net federal rate on income eligible for the SBD, versus 15% for the general rate.

Ontario has its own parallel deduction that lowers the provincial rate on the same first $500,000. The two together produce the “small business rate” you hear accountants talk about.

Who qualifies for the small business deduction?

Three conditions have to line up.

1. The corporation must be a CCPC all year

A CCPC is, broadly, a private corporation resident in Canada that isn’t controlled by non-residents, public corporations, or a combination of them. The T2 guide is clear that the corporation must have been a CCPC throughout the tax year. A change of control partway through the year can cost you the deduction for that year.

2. The income must be active business income

The SBD only applies to income from an active business carried on in Canada. Two kinds of income are carved out:

• Specified investment business income. This is a business whose main purpose is earning property income, such as interest, dividends, rent or royalties. It only qualifies if the corporation has more than five full-time employees throughout the year.
• Personal services business income. This is the “incorporated employee” situation, where you would reasonably be considered an employee of your client if the corporation didn’t exist. It also gets no SBD and faces a higher rate. Our post on employee vs. independent contractor status covers the warning signs.

3. The income must not be “specified corporate income”

If your corporation earns income by providing services or property to another private corporation that you (or someone not at arm’s length with you) have an interest in, that income is generally not eligible. The exception is when the other corporation assigns part of its own business limit to yours under subsection 125(3.2). This rule targets structures that multiply the $500,000 limit through related companies. It often catches professionals who bill a related operating company through their own holding company.

What are the 2026 small business rates in Ontario?

Ontario cut its small business rate from 3.2% to 2.2% effective July 1, 2026, according to the Ontario Ministry of Finance. The federal rates didn’t change.

If your tax year straddles July 1, 2026, the Ontario rate is prorated by the number of days before and after the change. A corporation with a December 31, 2026 year-end ends up with a combined small business rate of about 11.7% for 2026. From 2027 onward, a calendar-year corporation pays 11.2% for the full year.

One knock-on effect: Ontario is also cutting the tax credit on non-eligible dividends on January 1, 2027. Paying out low-rate corporate income as dividends will cost a little more personally, so the rate cut isn’t pure savings once you take money out. Our guide to salary vs. dividends in Ontario explains how the two changes interact.

How much does the small business deduction save?

The savings are easiest to see with round numbers.

You can model your own numbers with our corporate tax calculator.

How do associated corporations share the business limit?

The $500,000 limit isn’t per corporation. It belongs to the associated group. If you control two corporations, or you and your spouse together control companies in certain ways, the association rules in the Income Tax Act usually treat them as associated. The group then shares one $500,000 limit, allocated on Schedule 23. The T2 guide notes that the total of all percentages can’t exceed 100%.

A few practical points:

• Short tax years. If a tax year is shorter than 51 weeks, the business limit is prorated by the number of days in the year divided by 365. This often affects a corporation’s first year.
• Ontario follows the allocation. If a corporation assigns part of its federal business limit to another corporation, its Ontario limit drops by the same amount.
• Association is a technical test. Shares held by minor children, options and rights, and cross-ownership can all create association you didn’t expect. It’s worth reviewing before you set up a second company.

How does passive investment income reduce the small business deduction?

Many owners leave surplus profits in the corporation and invest them. That’s a sensible strategy, but it can shrink the federal SBD.

The rule looks at the group’s adjusted aggregate investment income (AAII) in the previous tax year. When AAII is between $50,000 and $150,000, the federal business limit drops by $5 for every $1 of AAII above $50,000. Once AAII passes $150,000, the federal limit is nil.

The good news for Ontario corporations: the Ontario Ministry of Finance states that Ontario does not parallel this federal measure. You keep the Ontario small business rate even if you lose the federal one.

Planning ideas include timing the sale of investments that produce capital gains, holding growth-oriented rather than income-producing assets, or using an individual pension plan. None of these are one-size-fits-all, so run the numbers first.

What is the taxable capital grind?

Larger CCPCs face a second reduction. When the associated group’s taxable capital employed in Canada in the previous year is between $10 million and $50 million, the business limit is reduced on a straight-line basis. At $50 million or more, there’s no SBD at all. This range applies to tax years beginning on or after April 7, 2022; before that, it was $10 million to $15 million. Ontario parallels this rule.

The passive income grind and the taxable capital grind don’t stack. Your business limit is reduced by whichever of the two produces the larger reduction. Most small owner-managed businesses never come close to $10 million of taxable capital, but growing groups with significant real estate or equipment should monitor it.

How do you claim the small business deduction?

There’s no separate application. The SBD is calculated on the T2 corporation income tax return. The deduction is based on the lowest of the corporation’s active business income, its taxable income and its business limit (after any assignments and grinds). Associated corporations file Schedule 23 to allocate the limit, and the Ontario deduction is calculated on the Ontario schedules filed with the T2.

Claiming the SBD also affects when your tax is due. A CCPC that claimed the SBD in the current or previous year, and whose previous-year taxable income (combined with associated corporations) didn’t exceed its business limit, generally gets three months after year-end to pay its balance instead of two. If you’re weighing whether incorporating makes sense at all, start with our guide on whether you should incorporate in Ontario.

How MNJ CPA can help

We prepare T2 returns for Ontario CCPCs and review association, specified corporate income and passive income issues before they cost you the deduction. If you’d like a second look at your structure or year-end, see our corporate tax services or contact us to set up a conversation.