What it actually costs to leave cash sitting in your corporation

Most incorporated professionals reach the same point: the corporation is earning more than the household spends, so cash accumulates. Leaving it invested inside the company feels efficient — the money was taxed at the small business rate, so there is more of it to invest.

That works until the investment income itself becomes the problem.

Two separate taxes are at work

First, passive investment income inside a CCPC is taxed at a high rate up front — roughly 50% in Ontario. A portion is refundable to the corporation later when taxable dividends are paid out, through the refundable dividend tax on hand (RDTOH) mechanism, so it is not permanently lost. But it is a real drag on compounding in the meantime.

Second, and less well understood: passive income reduces access to the small business deduction.

This is the part that surprises owner-managers. A portfolio inside the company yielding $150,000 does not just get taxed heavily itself — it re-rates your operating profit too.

Rough sense of scale

A corporation holding a $3,000,000 portfolio yielding 5% is generating $150,000 — enough to wipe out the deduction on its own. Plenty of successful practices get there without ever making an explicit decision to.

The options, honestly compared

• Pay more out personally. Unglamorous, but salary creates RRSP room ($33,810 of contribution room requires roughly $187,833 of earned income in 2026) and gets capital into TFSAs, where growth is genuinely tax-free.
• Individual Pension Plan (IPP). For owner-managers over roughly 45 with steady T4 income, an IPP often allows larger deductible contributions than an RRSP, and the assets sit outside the corporation. Setup and actuarial costs are real, so it needs scale.
• Corporate-owned permanent insurance. Growth inside an exempt policy is not passive investment income for the SBD grind, and on death the benefit less the policy's adjusted cost basis credits the capital dividend account — allowing a tax-free dividend to shareholders. Powerful for estate liquidity and share redemption funding.
• Holding company. Does not solve the grind on its own — associated corporations share the $50,000 threshold — but can help separate risk and clean up a share sale.

Where insurance genuinely fits, and where it does not

Corporate-owned permanent insurance is frequently oversold to this exact audience, so it is worth being blunt about the trade-off. It is a long-horizon estate and tax-structure tool, not an investment that competes with a portfolio on returns. Cash surrender value in the early years is well below premiums paid, and the CDA benefit is realised at death.

If the corporation might need that capital for the business in the next decade, or the shareholder's estate has no meaningful tax liability to fund, the case is weak. If there is a permanent tax bill coming at death — appreciated shares, a rental portfolio, a family cottage — and the corporation is going to hold surplus regardless, the case is strong.

The question to start from

Not 'what should the corporation invest in', but 'how much of this surplus will the family actually need to spend, and when'. The answer determines whether the right structure is personal, registered, corporate, insured, or some combination — and it is a very different answer at 40 than at 60.

Corporate tax tiers and the passive investment income grind depend on associated corporation limits and provincial tax brackets. A collaborative review with your corporate accountant and wealth planner helps ensure surplus capital is deployed in the most tax-efficient structure.