The short answer
A policy's adjusted cost basis starts with premiums paid but is reduced every year by the net cost of pure insurance, so it typically rises, peaks, and falls toward zero on permanent policies. It sets the taxable gain on surrender or withdrawal and the capital dividend account credit at death, in opposite directions.
corporate-life-insuranceAsk an owner what their corporate policy's tax cost is and the usual answer is the premiums paid so far. The Income Tax Act computes something different, called the adjusted cost basis, and the gap between the two numbers is not a technicality: it decides how much tax a surrender or withdrawal triggers while you hold the policy, and how much of the death benefit the capital dividend account receives at the end. This post explains what actually goes into the ACB, why it falls over time, and where the number bites.
The direct answer: a running total defined in subsection 148(9), premiums in, the annual net cost of pure insurance out, adjusted for policy loans, dividends, and prior dispositions, tracked by the insurer, not by you.
The adjusted cost basis starts intuitively enough: premiums paid are the main addition. But the definition then subtracts, every year, the net cost of pure insurance, along with adjustments for policy dividends received in cash, policy loans, and the ACB already consumed by earlier partial dispositions. The result is a number that only coincidentally resembles cumulative premiums, and the insurer computes it, because no policyholder reasonably could. It is reported on annual statements or on request, and every figure in this post ultimately comes from that insurer-confirmed calculation.
The direct answer: the net cost of pure insurance is the year's mortality charge, prescribed by Regulation 308, and on many permanent policies held to older ages its cumulative total overtakes cumulative premiums.
The net cost of pure insurance is the prescribed mortality rate for the insured's age applied to the policy's net amount at risk, the gap between the death benefit and the values already accumulated. It is policy-specific and not a simple curve, because the amount at risk shrinks as values grow while the mortality rate rises with age; the carrier illustration is the only reliable source for a given contract, a point covered in the deductibility post, where the same NCPI concept caps the collateral-loan deduction. What matters here is the direction: every year's NCPI is subtracted from the ACB. Early on, premiums exceed NCPI and the ACB rises. Later the relationship commonly flips, the ACB peaks and declines, and on many permanent policies held to advanced ages it may reach zero and stay there. The path is design-specific, not guaranteed, which is one more reason to read the carrier's own figures rather than assume the pattern.
The direct answer: policy dividends and policy loans also move the ACB, mostly downward, which is why the running total belongs with the insurer rather than a spreadsheet.
On a participating policy, dividends the insurer declares reduce the ACB, and once the ACB reaches zero further cash dividends are taxable income in the year received. Dividends automatically applied to paid-up additional coverage are generally handled differently: excluded on both sides of the computation rather than run through it as a reduction and a matching premium, so the standard paid-up-additions election tends to leave the ACB where the premiums and NCPI put it. The precise handling is design-specific. A policy loan reduces the ACB too, and repaying one restores it in part. None of these entries appear anywhere except the insurer's administration system, which is the practical point: the ACB is a number you request, not one you reconstruct.
The direct answer: the capital dividend account credit is the death benefit minus the ACB immediately before death, so every dollar of ACB the NCPI has drained is a dollar more that can exit the corporation tax-free.
When the corporation receives the death benefit, the amount above the policy's ACB at that moment credits the CDA, and the CDA pays out to shareholders tax-free by election. A policy whose ACB has declined to zero credits the entire benefit. This is the one place the drain works in your favour, and it is central to why corporately owned permanent insurance is an estate instrument: the tax attribute that erodes over the decades is exactly the one you want eroded at the end. The full architecture is in the corporately-owned life insurance guide.
The direct answer: surrenders, withdrawals, and policy loans are all measured against the ACB, and the excess is fully taxable income, not a half-taxed capital gain.
Surrender the policy and the cash surrender value above the ACB is a policy gain, fully taxable to the corporation in that year. The contrast with a portfolio matters: a stock sold at a profit is taxed on half the gain, as covered in capital gains inside a CCPC, while a policy gain has no inclusion-rate discount at all. A partial withdrawal is a partial disposition measured against a prorated slice of the ACB under subsection 148(4), so even modest access can be partly taxable once the ACB is low. And a policy loan from the insurer, unlike a bank loan secured by the policy, is itself a disposition taxable to the extent it exceeds the ACB. The pattern across all three: the lower the ACB has drifted, the more taxable every living-access route becomes.
The direct answer: a policy gain is investment income, taxed for an Ontario CCPC at the 50.17 percent passive rate, and section 125 expressly counts it in adjusted aggregate investment income in the surrender year.
For an incorporated professional managing the passive income grind, a surrender has a second cost beyond the gain itself. Section 125's definition of adjusted aggregate investment income expressly adds amounts in respect of life insurance policies included in the corporation's income, to the extent not already counted, so the gain lands in adjusted aggregate investment income on top of being taxed, for an Ontario CCPC, at the 50.17 percent passive rate rather than active-income rates, and a large one-year spike can grind the following year's small business limit. A decades-old policy with a large gain and a near-zero ACB can therefore be one of the most expensive assets in the corporation to liquidate. That is not an argument that surrender is never right; it is the reason the exit comparison belongs in a planning conversation, the kind described in financial planning for physicians, before the surrender form.
The direct answer: one illustrative policy, an $80,000 ACB, a $600,000 cash surrender value, and a $1,500,000 death benefit, shows the two exits pointing opposite ways.
Take a corporately owned policy, decades in, with those three figures, all illustrative and all obtainable from the insurer on request. Surrender it and the policy gain is $600,000 minus $80,000, a fully taxable $520,000 that costs an Ontario CCPC $260,884 at the 50.17 percent passive rate before any refundable recovery, and drops the same $520,000 into AAII for the grind arithmetic. Hold it to death instead and the capital dividend account credit is $1,500,000 minus the same $80,000: $1,420,000 that can be paid to the estate tax-free by election, with only the $80,000 remainder exiting as an ordinary taxable dividend. The identical ACB drives both results, in opposite directions, and the CDA estimator runs this arithmetic for any set of inputs.
The direct answer: moving a policy between a shareholder and the corporation is a disposition at the greatest of cash surrender value, the fair market value of the consideration, and the ACB, which is why ownership should be right at issue.
A policy transferred in a non-arm's-length transaction, the shareholder selling a personal policy to the corporation or the corporation distributing one out, is deemed disposed of under subsection 148(7) at the greatest of the policy's cash surrender value, the fair market value of any consideration given, and its ACB. The rule closed an old planning gap and makes late restructuring expensive: a gain can be triggered on the way in or out, on top of any shareholder benefit analysis. The cheap version of getting ownership right is the application form; the expensive version is a transfer years later measured by this rule.
The direct answer: get the current ACB from the insurer once a year, keep the issue illustration as a reference only, and price any surrender, withdrawal, loan, or transfer against the insurer-confirmed figure before signing anything.
The ACB is not a number to manage so much as a number to know. It typically rises, peaks, and falls on a schedule the contract set in motion at issue, and the planning consequences flow from where it sits today: high early ACB softens the tax on access if plans change, low late ACB maximizes the CDA credit the structure was built for. The one habit that captures all of it is asking the insurer for the current figure before any policy decision, because every rule in this post keys off the ACB computed at that moment, not the projection made at issue.
No. Premiums are the main addition, but the adjusted cost basis is reduced every year by the net cost of pure insurance, the mortality charge computed under Regulation 308. On a permanent policy held for decades the deductions commonly overtake the additions, which is why an old policy's ACB is often far below cumulative premiums, and on many designs may reach zero.
The capital dividend account credit is the death benefit minus the ACB immediately before death, so a low ACB means more of the benefit can leave the corporation tax-free. Before death the arithmetic points the other way: surrender proceeds are taxed on the excess over the ACB, and withdrawals on the excess over a prorated portion of it, so a low ACB means a larger fully taxable gain.
The excess of the cash surrender value over the adjusted cost basis is fully taxable income to the corporation in the year of surrender. It is a policy gain, not a capital gain, so no half inclusion applies, and as investment income of an Ontario CCPC it is taxed at the 50.17 percent passive rate before any refundable mechanics.
From the insurer. Carriers track the adjusted cost basis and report it on annual statements or on request, and any transaction decision should use that insurer-confirmed figure rather than the projected column in the original illustration. The illustration is a reference document; the ACB that matters is the one computed as of the transaction date.
