The Tax Rate You're Using on Your Corporate Investment Account Is Probably Wrong
Most business owners run a quick mental calculation when deciding whether to leave surplus cash inside the corporation or pay it out. They compare their personal tax rate to the corporate rate, assume the lower number wins, and move on. The calculation is sensible. The rate they're using is often fictional.
The confusion starts with how passive income is taxed inside a Canadian Controlled Private Corporation. Active business income, what the company earns from operations, is taxed at around 12% federally on the first $500,000, thanks to the Small Business Deduction. Passive income, which includes interest, foreign dividends, and rental income from investments, is taxed at roughly 50% upfront before any refunds. That number shocks people when they first see it.
But the 50% figure is not the end of the story, and this is where most planning goes sideways. The high initial rate triggers a credit to something called the Refundable Dividend Tax on Hand account. When the corporation later pays dividends to shareholders, it gets a partial refund from this RDTOH pool. After the refund, the effective rate on passive income drops closer to the rate an individual would pay. The system is designed so that earning investment income inside or outside the corporation should produce roughly the same total tax. This is called tax integration, and it works, when the numbers are run correctly.
Where it breaks is in the calculation most owners actually perform. They see the 12% active rate, assume all corporate income is taxed at 12%, and conclude that leaving investment income inside the company is always the better move. It isn't. The 50% rate applies the moment the corporation earns a dollar of interest or a foreign dividend. The RDTOH refund only happens when dividends are paid out, which means the high rate sits on the balance sheet, dragging on returns, until someone remembers to trigger the refund. Many owners never track the RDTOH account closely enough to know how much is sitting there.
The SBD grind makes it worse
The system doesn't just tax passive income heavily. It punishes it. For every dollar of passive income above $50,000, the corporation loses $5 of its Small Business Deduction limit. A corporation earning $150,000 in passive income loses the entire SBD and pays the higher general corporate rate on all its active business income. That threshold is not hypothetical. A $1.5 million portfolio yielding 4% in interest crosses it.
This is where the mental math collapses entirely. The business owner who thought they were deferring tax at 12% is actually triggering a tax rate north of 26% on operations, on top of the 50% on the investments themselves. The combined effect is a marginal rate most owners would never tolerate if they could see it plainly.
Asset location solves half of it
Capital gains are taxed more lightly than interest inside a corporation. Only 50% of a capital gain is taxable, and the tax-free portion can be withdrawn through the Capital Dividend Account without personal tax. This makes growth-oriented equity portfolios more efficient than GICs or bond ladders when held corporately.
The better move for most owners is to hold fixed-income investments inside a Tax-Free Savings Account or Registered Retirement Savings Plan, where they produce no taxable income, and keep equity exposure inside the corporation where capital gains treatment applies. The same dollar of return produces a meaningfully different tax result depending on where the asset sits.
Track the refund or lose it
The RDTOH account is not automatic. It requires the corporation to actually pay dividends to shareholders to trigger the refund. Owners who reinvest all profits and never pull cash personally can recover tens of thousands of dollars by coordinating personal cash flow needs with corporate dividend payments, since the refund is $1 for every $2.61 of eligible dividends paid.
None of this is intuitive, and most of it runs against the instinct to leave money where the rate looks lowest. The rate that looks lowest is often the one that doesn't apply.
Most business owners run a quick mental calculation when deciding whether to leave surplus cash inside the corporation or pay it out. They compare their personal tax rate to the corporate rate, assume the lower number wins, and move on. The calculation is sensible. The rate they're using is often fictional.
The confusion starts with how passive income is taxed inside a Canadian Controlled Private Corporation. Active business income, what the company earns from operations, is taxed at around 12% federally on the first $500,000, thanks to the Small Business Deduction. Passive income, which includes interest, foreign dividends, and rental income from investments, is taxed at roughly 50% upfront before any refunds. That number shocks people when they first see it.
But the 50% figure is not the end of the story, and this is where most planning goes sideways. The high initial rate triggers a credit to something called the Refundable Dividend Tax on Hand account. When the corporation later pays dividends to shareholders, it gets a partial refund from this RDTOH pool. After the refund, the effective rate on passive income drops closer to the rate an individual would pay. The system is designed so that earning investment income inside or outside the corporation should produce roughly the same total tax. This is called tax integration, and it works, when the numbers are run correctly.
Where it breaks is in the calculation most owners actually perform. They see the 12% active rate, assume all corporate income is taxed at 12%, and conclude that leaving investment income inside the company is always the better move. It isn't. The 50% rate applies the moment the corporation earns a dollar of interest or a foreign dividend. The RDTOH refund only happens when dividends are paid out, which means the high rate sits on the balance sheet, dragging on returns, until someone remembers to trigger the refund. Many owners never track the RDTOH account closely enough to know how much is sitting there.
The SBD grind makes it worse
The system doesn't just tax passive income heavily. It punishes it. For every dollar of passive income above $50,000, the corporation loses $5 of its Small Business Deduction limit. A corporation earning $150,000 in passive income loses the entire SBD and pays the higher general corporate rate on all its active business income. That threshold is not hypothetical. A $1.5 million portfolio yielding 4% in interest crosses it.
This is where the mental math collapses entirely. The business owner who thought they were deferring tax at 12% is actually triggering a tax rate north of 26% on operations, on top of the 50% on the investments themselves. The combined effect is a marginal rate most owners would never tolerate if they could see it plainly.
Asset location solves half of it
Capital gains are taxed more lightly than interest inside a corporation. Only 50% of a capital gain is taxable, and the tax-free portion can be withdrawn through the Capital Dividend Account without personal tax. This makes growth-oriented equity portfolios more efficient than GICs or bond ladders when held corporately.
The better move for most owners is to hold fixed-income investments inside a Tax-Free Savings Account or Registered Retirement Savings Plan, where they produce no taxable income, and keep equity exposure inside the corporation where capital gains treatment applies. The same dollar of return produces a meaningfully different tax result depending on where the asset sits.
Track the refund or lose it
The RDTOH account is not automatic. It requires the corporation to actually pay dividends to shareholders to trigger the refund. Owners who reinvest all profits and never pull cash personally can recover tens of thousands of dollars by coordinating personal cash flow needs with corporate dividend payments, since the refund is $1 for every $2.61 of eligible dividends paid.
None of this is intuitive, and most of it runs against the instinct to leave money where the rate looks lowest. The rate that looks lowest is often the one that doesn't apply.
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