Many incorporated Canadian business owners and professionals accumulate investment assets inside their corporations over time. Understanding how passive income is taxed inside a corporation — and how it interacts with the Small Business Deduction — is essential for anyone with significant retained earnings invested corporately.
This guide covers how investment income is taxed inside a CCPC, the RDTOH refund mechanism, the passive income grind-down rule, and strategies to manage passive income efficiently.
Passive income (also called "investment income" in the corporate context) is income earned from sources other than the active business — primarily:
Canadian dividends received from connected corporations are generally excluded from the passive income definition for the SBD grind-down calculation (though they may still affect RDTOH).
Investment income earned inside a Canadian-controlled private corporation is taxed at a high "top-up" rate designed to eliminate the deferral advantage from earning passive income corporately versus personally. The combined federal-provincial rate on corporate investment income is approximately:
The Refundable Dividend Tax on Hand (RDTOH) is a notional account that tracks refundable corporate tax. When a CCPC pays certain types of dividends, it receives a refund from its RDTOH balance at a rate of $1 refunded for every $2.61 of taxable dividends paid.
There are two RDTOH accounts:
The refund mechanism means that while the corporation pays high rates on investment income upfront, a substantial portion of that tax is recovered when the corporation eventually distributes dividends. The system is designed so total tax on investment income earned inside a corporation and paid out as dividends equals (approximately) what an individual would have paid on the same income directly.
Since 2018, a CCPC's Small Business Deduction is reduced when the associated group earns more than $50,000 of passive income annually:
The $50,000 threshold applies to "adjusted aggregate investment income" (AAII) — a specific calculation based on total investment income of the corporate group.
A corporation with $2 million invested at 5% earns $100,000 in investment income — already above the $50,000 threshold, causing a partial SBD grind-down. A corporation with $3 million earning 5% generates $150,000 in investment income — completely eliminating the SBD. For mature professional corporations with substantial retained earnings, this is a live planning issue.
Permanent life insurance (whole life, universal life) with an exempt policy designation accumulates investment growth tax-free inside the policy. Crucially, the growth does not count as passive investment income for purposes of the SBD grind-down calculation. Corporate-owned insurance is the most powerful tool for sheltering investment growth from both tax and the passive income threshold.
Capital gains are only included in passive income (AAII) at 50% — i.e., only the taxable portion of capital gains counts. A portfolio focused on capital-appreciation equities (rather than interest-bearing fixed income) generates less AAII per dollar of return compared to a bond portfolio. ETFs and growth-oriented equities held to minimize realized gains can reduce AAII.
The simplest approach: extract retained earnings from the corporation before they generate significant passive income. This means accepting the personal tax on extraction earlier rather than accumulating corporately. For owners approaching the passive income threshold, this may be the most straightforward path.
If the corporation is actively managing rental properties (rather than passively holding them), rental income may qualify as active business income rather than passive income. The threshold between active and passive rental activity is fact-specific and requires advice from a tax accountant.
Shifting investment activity to a separate holding company can sometimes isolate passive income from the operating company. However, associated corporation rules mean investment income in a holding company associated with the opco still counts for the AAII calculation. Independent holding companies without association may provide some relief, but the rules are complex.
The 2024 federal budget increased the capital gains inclusion rate from 50% to 66.67% for corporations (and trusts) — no $250,000 threshold applies to corporations. All capital gains in a corporation are now included at 66.67%, increasing the effective tax rate on corporate capital gains from approximately 25% to approximately 33.3% (before RDTOH refunds).
This makes the timing and management of capital gains inside a corporation more important. Tax-loss harvesting, deferring realizations, and strategic use of the Capital Dividend Account (CDA) — which still captures 33.33% of capital gains as tax-free for future dividend extraction — all require annual review.
Passive income in a corporation is not inherently problematic — the RDTOH system largely neutralizes the permanent tax advantage. The key issues are the SBD grind-down (affecting future active income tax rates) and the 2024 capital gains rate change (affecting the cost of realizing gains inside the corporation). Both require active management as your corporate investment portfolio grows.
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