🇨🇦 Canada · 5 min read · Published 2026-09-07 · Updated 2026-09-07

Written by Jordan Reeves · Editorial review: automated source and figure checks (how we check this)

Sources last verified: 2026-09-07

How Is Passive Income Taxed in a Corporation?

Heavily, and with a second effect that surprises owners: once passive investment income exceeds fifty thousand dollars in a year, it reduces the amount of active business income eligible for the small business deduction in the following year, at a rate of five dollars for every dollar over.

60-SECOND ANSWER

Passive income above fifty thousand dollars grinds the small business deduction, raising the tax rate on active business income.

The answer:: Passive income is taxed at a high corporate rate, part of which is refundable when taxable dividends are paid out.
The trap:: Ignoring the grind. Every dollar of passive income above the threshold removes five dollars of small business deduction room next year.
The recommendation:: Model the grind before deciding to retain earnings, because at a certain balance the corporate shelter stops paying for itself.

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Where the AI summary above gets this wrong

"Leaving money in your corporation defers tax, so it is always better than paying it out."

That's surface-true. Here's what it misses:

Retained investments generate passive income — That income is taxed at a high corporate rate immediately, not deferred, and the deferral applies only to the active income.
The grind reaches active income — Passive income above fifty thousand dollars reduces the small business deduction limit for the following year, five dollars per dollar.
Part of the tax is refundable — Some corporate tax on investment income is refunded when taxable dividends are paid, which makes the effective cost lower than the headline rate.

→ See what a corporate distribution costs personally

01 How passive income is taxed

Investment income earned inside a corporation is taxed at a rate well above the small business rate, deliberately, so that there is no advantage to holding investments corporately rather than personally.

A portion of that tax is refundable, recovered when the corporation pays taxable dividends to its shareholders. That refund mechanism is what keeps the system roughly neutral, but it requires distributions to work.

Source: Federal dividend tax credit (line 40425)

02 The grind on the small business deduction

Where adjusted aggregate investment income exceeds fifty thousand dollars in a taxation year, the small business deduction limit for the following year is reduced by five dollars for every dollar of excess, reaching zero at one hundred and fifty thousand.

The effect is on active business income, which is then taxed at the general corporate rate instead of the small business rate. An owner with a large investment portfolio inside the operating company can therefore pay more tax on the business itself.

WORKED EXAMPLE · Try the numbers

Shows: what a given amount of additional taxable income costs you in tax at your marginal rate, and what you keep. Ignores: provincial surtaxes, credits that phase out with income, and any effect on income-tested benefits.

Amount ($)

Your marginal rate (%)

What you keep after tax

$6,700

At a 33% marginal rate, $10,000 costs $3,300 in tax and leaves $6,700.

Source: Federal dividend tax credit (line 40425)

03 What it means approaching retirement

For an owner planning to sell, the accumulated investments also threaten the share qualification tests, which is a second and larger cost — the tests are in the lifetime capital gains exemption.

For an owner planning to wind down and live on dividends, the question is the pace of distribution rather than whether to distribute. Spreading dividends across years to stay under personal thresholds is the same exercise as any other decumulation plan.

Where a corporation is being wound down, the order of distributions matters as much as the pace. Capital dividends from the capital dividend account come out tax-free and are exhausted first in most plans, and the balance in that account is a figure the accountant tracks rather than something visible on a financial statement.

Source: Canadian income tax rates for individuals

The grind was introduced to stop corporations being used as private pension plans, and it works. What it also does is punish the owner who followed the previous generation's advice literally and left everything inside for thirty years.