- An ordinary allowable capital loss can only be deducted against allowable capital gains for the year, with any unused amount subject to the general capital loss carryback and…
- An ABIL generally arises from a loss on shares or debt of a small business corporation — broadly, a Canadian-controlled private corporation that uses substantially all of its assets in…
- An ABIL doesn't require you to find a buyer and sell your shares outright.
Most capital losses live in a narrow lane: they can only offset capital gains, with the excess carried back or forward for later years. If you lose money on shares or a loan to a small Canadian business — your own startup, or one you invested in personally — the Income Tax Act offers a meaningfully better result through the Allowable Business Investment Loss, or ABIL: a loss that can reduce almost any source of income, not just capital gains.
This article explains what makes an ABIL different, what has to happen before you can claim one, and where the extra benefit comes with a trade-off.
What Makes an ABIL Different From an Ordinary Capital Loss
An ordinary allowable capital loss can only be deducted against allowable capital gains for the year, with any unused amount subject to the general capital loss carryback and carryforward rules. An ABIL is different in one important respect: it can be deducted against any source of income in the year it arises — employment income, business income, other investment income, or capital gains. For a taxpayer without offsetting capital gains that year, that difference can be worth a great deal.
What Has to Be True Before an ABIL Is Available
An ABIL generally arises from a loss on shares or debt of a small business corporation — broadly, a Canadian-controlled private corporation that uses substantially all of its assets in an active business carried on primarily in Canada. Before assuming a loss qualifies, confirm each of the following, ideally with a tax professional:
- [ ] The corporation is a Canadian-controlled private corporation.
- [ ] The corporation's assets are used primarily in an active business, not passive investments like real estate holdings or a securities portfolio.
- [ ] You personally held shares of the corporation, or the corporation — or a party related to it — owes you a debt.
- [ ] The loss has actually crystallized, through an arm's-length sale, the corporation's bankruptcy or insolvency, or a debt properly established as uncollectible, rather than simply reflecting a drop in value.
- [ ] You are an individual, or in some cases a trust; corporations have their own, different rules for investment losses of this kind.
How the Loss Gets Established
An ABIL doesn't require you to find a buyer and sell your shares outright. It can also arise where:
- The corporation becomes bankrupt during the year;
- The corporation is insolvent and a winding-up order has been made, or it is otherwise clear the corporation will be dissolved and its shares are worthless; or
- A debt owed to you by the corporation becomes a bad debt that has been properly established as uncollectible.
Each route carries its own conditions and its own documentation expectations. Claiming the loss too early, or without the paperwork to support the corporation's financial condition, is one of the more common reasons the CRA denies or delays an ABIL claim on review.
How Much of the Loss You Can Deduct
An ABIL is calculated the same way as an ordinary capital loss and then reduced by the same fraction that applies to capital gains generally — currently one-half, as of mid-2026 (verify the current inclusion rate before you file, since this figure has been the subject of proposed changes in recent years). The result is your Allowable Business Investment Loss: deductible against income generally, rather than restricted to capital gains the way an ordinary allowable capital loss is.
ABIL vs. Ordinary Capital Loss at a Glance
| Ordinary allowable capital loss | Allowable Business Investment Loss (ABIL) | |
|---|---|---|
| What it offsets | Capital gains only | Any source of income |
| Typical source | Sale of capital property generally | Shares or debt of a qualifying small business corporation |
| Trigger events | Usually a straightforward sale | Sale, bankruptcy, insolvency and winding-up, or an established bad debt |
| Other effects | Generally none beyond the capital loss rules | Can affect your future access to the Lifetime Capital Gains Exemption |
The Trade-Off: Your Lifetime Capital Gains Exemption
Claiming an ABIL is not free of consequences elsewhere on your return. It can interact with other calculations that affect your future access to the Lifetime Capital Gains Exemption on qualifying small business shares, or farm or fishing property, in later years. This interaction is technical, easy to get wrong, and depends heavily on your other investment activity — get advice before claiming a large ABIL if you expect to rely on the exemption down the road.
Frequently asked questions
My private company shares have dropped sharply in value. Can I claim an ABIL now?
Not on that basis alone. A drop in value isn't enough by itself — the loss generally needs to have crystallized through a sale, the corporation's bankruptcy or insolvency, or a debt properly established as uncollectible.
I lent money personally to a friend's small corporation, and it folded. Does that qualify?
Possibly, if the corporation meets the small business corporation conditions and the debt is properly established as uncollectible under the applicable rules. Loans to unincorporated businesses or sole proprietors are treated differently, so get specific advice on how the loan was structured.
Does an unused ABIL expire if I don't use it right away?
Unused amounts follow their own carryback and carryforward treatment, which can differ from an ordinary capital loss and can change in character over time if it remains unused. Confirm the current rules with a tax professional rather than assuming an unlimited window.
Do I need the corporation to be completely wound up before I can claim the loss?
Not necessarily. Bankruptcy, a clear insolvency and winding-up situation, or an arm's-length sale can each support a claim on their own, depending on the facts — full dissolution of the corporation isn't always required first.
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