Small Business Deduction

Who gets it, and on what income

The SBD belongs to the Canadian-controlled private corporation (CCPC): in one plain sentence, a private corporation resident in Canada that is not controlled by non-residents or by public companies. Public corporations and foreign-controlled companies pay the general corporate rate on everything.

It also only applies to active business income: profit from actually carrying on a business, selling goods, billing clients, running operations. Passive income, meaning interest, rents, portfolio dividends and gains earned on investments the corporation holds, is deliberately taxed at high corporate rates instead, so that a corporation cannot double as a cheap personal investment account. The deduction reduces the federal rate to 9% on the first $500,000 of active business income in the corporation's taxable income each year; active income above the limit pays the general rate. One soft caution: associated corporations must share a single $500,000 limit, so splitting one business into several companies does not multiply the deduction.

The rate in practice

Provinces layer their own small business rates on top of the federal 9%. The combined federal and provincial rate lands roughly between 9% and 12.2% depending on the province. Set that against general corporate rates in the high twenties and top personal rates above 50% in most provinces, and the appeal is obvious: a dollar of small-business profit keeps close to 90 cents working inside the company.

The passive income grind

Since profits left inside are often invested, many corporations gradually build investment portfolios, and this is where the rules push back. When a CCPC's investment income (together with associated corporations) exceeds $50,000 in a year, the $500,000 SBD limit for the next year shrinks by $5 for every $1 over the threshold, disappearing entirely at $150,000 of investment income.

What the grind means for planning

The consequence is that a large investment portfolio inside the corporation quietly erodes the very deduction that made the money accumulate. A portfolio of a few million dollars can throw off enough interest and dividends to grind the limit substantially. This is why advisors to incorporated professionals talk about strategies whose returns do not count as passive investment income, corporate-owned life insurance being the one most often raised, alongside choices about what to hold inside versus outside the company. These are individual planning decisions with their own trade-offs, not automatic answers.

A separate ceiling applies to genuinely large companies: the $500,000 limit also phases out as taxable capital employed in Canada rises between $10 million and $50 million.

What the SBD is really for: deferral, not avoidance

The low rate looks like a gift, but it is better understood as a deferral. Money taxed at 9% to 12.2% inside the corporation must eventually come out to be spent, as salary or as dividends, and it is taxed personally at that point. The system's integration design aims to make the combined corporate-plus-personal bill land close to what you would have paid earning the income directly. Because SBD-rate income bore so little corporate tax, it comes out as non-eligible dividends, which carry a smaller dividend tax credit than eligible dividends do, squaring the account.

Deferral is still genuinely valuable. Profit reinvested inside the corporation compounds on a nearly full pre-tax dollar rather than the roughly half-dollar left after top personal rates, and over a decade or two that difference in the compounding base is substantial. The SBD rewards owners who leave money working in the business; it hands little lasting advantage to owners who pull every dollar out each year.