Every investor wants to pay less tax — and tax-loss harvesting is one of the few legal strategies that lets you turn a losing investment into a genuine tax advantage. Used correctly, it reduces the capital gains tax you owe in the current year, recovers tax paid in prior years, or builds a loss reserve you can draw on for years to come. This guide covers exactly how tax-loss harvesting works in Canada, the rules you must follow to avoid a denied loss, and the practical steps to execute the strategy before year-end.
Tax-loss harvesting is the deliberate sale of an investment held in a non-registered account that is currently worth less than you paid for it. By selling the position, you crystallise a capital loss. That capital loss can then be applied against capital gains you have realised in the same year, reducing the net taxable amount included in your income. The investment itself may still have a place in your portfolio — the goal is to capture the tax value of the loss, not necessarily to exit the position permanently.
The key phrase is non-registered account. Tax-loss harvesting has no effect inside a TFSA or RRSP. Losses realised within registered accounts are simply absorbed by the account with no deduction available to you — more on that below.
Under the Income Tax Act, capital losses can only offset capital gains. They cannot reduce employment income, rental income, business income, or any other source. This is the single most important constraint of the strategy: if you have no capital gains to offset, the loss still has value, but you cannot apply it immediately against other income.
When you realise a capital loss, only 50% of the loss is included in the calculation — the same inclusion rate that applies to capital gains. So a $2,000 capital loss produces a $1,000 allowable capital loss that reduces your taxable income. Crucially, the inclusion rate on losses always mirrors the rate on gains: if Parliament ever changes the capital gains inclusion rate, both sides move together, preserving the offset.
If your allowable capital losses exceed your allowable capital gains in a given year, you have a net capital loss. You have two choices:
Canada's superficial loss rule exists to prevent investors from selling an investment purely for the tax loss while immediately repurchasing the same position. If the rule applies, your loss is denied — not permanently, but it is added to the adjusted cost base (ACB) of the replacement asset, deferring the benefit until that asset is eventually sold.
The rule triggers when you, or an affiliated person, acquires the same or identical property within the period starting 30 days before the sale and ending 30 days after the sale, and you or an affiliated person still holds the property at the end of that 30-day window after the sale.
Affiliated persons include:
Note that the CRA does not currently consider a TFSA an affiliated person for the superficial loss rule. That said, caution is warranted: repurchasing inside a TFSA immediately after selling at a loss in a non-registered account is a grey area, and the CRA has expressed concern about the practice in certain contexts. Waiting out the 31-day window remains the cleanest approach.
You have two practical ways to sidestep the rule without abandoning your market exposure:
The simplest approach is to wait at least 31 calendar days after the sale before repurchasing the same investment. During that window, you are exposed to market movements — the stock or ETF could recover, and you would miss that gain. That is the real cost of tax-loss harvesting: temporary loss of the exact position.
A more common technique is to immediately purchase a similar investment that gives you comparable market exposure without being "identical property." For example, if you sell iShares Core S&P/TSX Capped Composite Index ETF (XIC) at a loss, you could immediately purchase iShares S&P/TSX 60 Index ETF (XIU). Both track broad Canadian equity markets, but they are not the same fund with the same underlying index. You maintain equity exposure, realise the capital loss, and avoid the superficial loss rule. Work with an advisor to identify suitable swap pairs for your specific holdings.
Suppose you purchased 100 shares of a Canadian mining company for a total adjusted cost base of $5,000. Today those shares are worth $3,000 — a paper loss of $2,000. You also realised a $4,000 capital gain earlier in the year from selling a different stock.
By selling the mining shares before December 31, you crystallise a $2,000 capital loss. The allowable capital loss (50%) is $1,000, which offsets $1,000 of your $2,000 allowable capital gain (50% of $4,000). Your net taxable capital gain for the year drops from $2,000 to $1,000 — saving you real tax dollars depending on your marginal rate.
If you still believe in the long-term thesis for that mining company, wait 31 days and repurchase. Your new ACB will be $3,000 (the repurchase price), so future gains or losses will be calculated from that new base.
A capital loss is realised on the trade date, not the settlement date, for tax purposes in Canada. However, the trade must actually settle within the tax year for the loss to count. With Canadian equities now settling on a T+1 basis (one business day after the trade), you need to execute your sell orders by December 30 to ensure settlement by December 31 for the 2025 tax year. If December 30 falls on a weekend or holiday, move your deadline earlier. Missing this window by a single day pushes the loss into the following tax year.
Capital losses realised inside a TFSA or RRSP are entirely useless from a tax-loss harvesting perspective. The loss is not deductible, it does not reduce your contribution room, and it cannot be carried anywhere. Tax-loss harvesting is strictly a non-registered account strategy. If you hold a depreciated investment inside a registered account, the correct move from a tax perspective is to simply hold it and wait for a recovery — selling it accomplishes nothing on the tax front.
If you invest through a Canadian-controlled private corporation (CCPC), the same basic principle applies: capital losses inside the corporation can only offset capital gains inside the corporation. You cannot flow a corporate capital loss through to your personal return. The corporation carries the loss back three years or forward indefinitely against its own capital gains. There is no mechanism to extract the tax value of a corporate capital loss for personal use.
Shareholders of professional or holding corporations often overlook this limitation. If your investment portfolio sits inside a corporation, tax-loss harvesting still makes sense at the corporate level — just do not expect any personal tax relief from it.
Tax-loss harvesting sounds straightforward but involves ACB tracking, wash sale analysis across multiple account holders and entities, T1A carryback filings, and coordination with your investment advisor. Errors in ACB calculations compound over time and can lead to either over-reporting or under-reporting gains at disposition. The team at Swift Accounting Calgary works with individual investors and business owners to identify harvesting opportunities, calculate accurate ACBs, and file carryback adjustments where prior-year gains can be recovered. If you hold significant non-registered investments, a year-end review is worth scheduling before December 30.
Reaching out to Swift Accounting early — ideally in October or November — gives you time to identify loss positions, choose appropriate replacement securities with your investment advisor, and execute trades before the settlement deadline.
No. Under the Income Tax Act, capital losses can only be applied against capital gains. If you have no capital gains in the current year, the net capital loss must be carried back (up to three years) against prior capital gains, or carried forward indefinitely against future capital gains. It cannot reduce salary, rental income, or self-employment income.
No — your spouse is an affiliated person under the superficial loss rule. If your spouse repurchases the same or identical property within the 30-day window before or after your sale, the loss will be denied and added to the ACB of the shares your spouse now holds. To preserve the loss, both you and your spouse must refrain from repurchasing the identical investment for 31 days, or you must switch to a similar but non-identical security.
You file a T1A — Request for Loss Carryback with the CRA. This form adjusts your taxable income in the prior year, and the CRA issues a refund of the tax you overpaid on capital gains in that year. You can go back up to three tax years. The T1A is filed for the year in which the loss arose, and it does not require you to refile your prior-year return from scratch.
It depends. If your marginal tax rate is low, the immediate dollar savings are smaller, but losses carried forward can be applied in future years when your income — and marginal rate — may be higher. If you anticipate higher income from a business sale, property sale, or RRSP/RRIF withdrawals in retirement, preserving capital losses now can provide meaningful future tax savings. A tax advisor can model out the present value of the benefit given your specific projected income.
Tax-loss harvesting is one of the most accessible year-end tax strategies available to Canadian investors — but timing, the superficial loss rule, and accurate ACB records make execution details matter. Whether you are managing a personal non-registered account or a corporate investment portfolio, getting the mechanics right is essential to actually realising the benefit. Contact Swift Accounting to schedule a year-end tax planning review and make sure your investment losses are working as hard as possible before December 31.
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