Capital loss carryforward in Canada: rules, examples, and how to claim it
Published: Sep 29, 2026
Investing in capital markets may involve both gains and losses over time. In Canada, tax rules recognize that investments in capital property, such as stocks, exchange-traded funds, and certain mutual funds, may decline in value as well as increase. When an investor sells a capital asset for less than its adjusted cost base, the difference may result in a capital loss.
Canadian tax rules provide mechanisms that allow investors to use net capital losses to reduce the tax impact of capital gains. These rules include the ability to offset capital gains, apply losses to previous years, or apply them to future capital gains.
This article explains how capital loss carryforward in Canada works, including key rules, examples, and how losses may be reported to the Canada Revenue Agency (opens in a new tab) (CRA).
Understanding capital losses in Canada
A capital loss generally occurs when an investor sells capital property for less than its purchase cost.
Capital property may include:
Shares of publicly traded companies
Exchange-traded funds (ETFs)
Mutual funds
Certain investment properties
Other financial investments held for capital appreciation
To calculate a gain or loss, investors typically compare the selling price of an asset with its adjusted cost base (ACB).
Simplified example:
Purchase price of shares: $10,000
Selling price: $7,000
Capital loss: $3,000
If an asset is sold at a loss, the amount may contribute to capital losses for that tax year.
Taxable capital gains and the inclusion rate
In Canada, not all capital gains are fully taxable. Instead, tax rules apply a capital gains inclusion rate to determine the taxable portion.
Historically, the inclusion rate has been 50% for individuals. This means that only half of the capital gain is typically included in taxable income.
For example:
Total capital gain: $4,000
Inclusion rate: 50%
Taxable capital gains: $2,000
The same concept applies when calculating losses. Only the taxable portion of losses (called net capital losses) can be used to offset taxable capital gains.
Net capital losses explained
A net capital loss occurs when total capital losses for the year exceed total capital gains.
Example:
Total capital gains: $2,000
Total capital losses: $6,000
After applying the inclusion rate:
Taxable capital gains: $1,000
Allowable capital losses: $3,000
In this example, the investor would have unused net capital losses of $2,000 that may be applied to other tax years.
These unused capital losses may be used to reduce taxable capital gains from other years under CRA rules.
Capital loss carryback rules
Canadian tax rules allow investors to apply net capital losses to certain previous years through a process called capital loss carryback.
A carry back allows losses from the current tax year to be applied to taxable capital gains reported in earlier years.
Key features include:
Losses may generally be applied to the three previous years.
The process requires submitting a request to the Canada Revenue Agency.
Adjustments may appear in updated records, such as the Notice of Assessment.
This process may reduce tax that was previously paid on capital gains.
Capital loss carryforward rules
If capital losses cannot be fully applied to earlier years, they may be carried forward indefinitely.
This means that unused net capital losses may be applied to future capital gains in a future year.
There is no expiration date under current rules, so losses can remain available until they are used to offset future capital gains.
These losses are tracked by the CRA and typically appear on the investor’s Notice of Assessment.
How capital loss carryforward works
The capital loss carryforward system operates in several steps.
Step 1: calculate capital gains and losses from sales of capital property
At the end of the tax year, investors calculate total gains and losses from sales of capital property.
This calculation requires information, such as:
Selling price
Adjusted cost base
Transaction costs
Step 2: apply the inclusion rate
The inclusion rate determines the taxable portion of gains and allowable portion of losses.
Historically:
Capital gains inclusion rate: 50%
Allowable capital loss: 50% of total loss
Step 3: determine net capital losses
If allowable capital losses exceed taxable capital gains, the difference becomes net capital losses.
Step 4: apply losses to other years
The investor may then:
Carry back losses to previous years, or
Apply them to future capital gains
Example of capital loss carryforward
Consider a simplified scenario.
Year 1:
Capital gain: $8,000
Taxable capital gains (50% inclusion): $4,000
Year 2:
Capital loss: $10,000
Allowable capital loss: $5,000
In this case:
The allowable loss exceeds the previous taxable capital gain.
The investor could choose to carry back $4,000 of losses to offset the earlier taxable gain.
The remaining $1,000 could remain as unused net capital losses and be carried forward indefinitely to apply against future capital gains.
Reporting capital losses on a Canada Revenue Agency tax return
Capital gains and losses are reported on the income tax return filed with the Canada Revenue Agency.
The process generally involves:
Reporting dispositions of capital property on Schedule 3 of the tax return
Calculating taxable capital gains and allowable losses
Recording any net capital losses
The CRA then updates the taxpayer’s records and may report remaining unused capital losses on the Notice of Assessment.
This document can help investors track available losses for future use.
How the Notice of Assessment tracks losses
After a tax return is processed, the CRA issues a Notice of Assessment.
This document may include information about:
Remaining unused net capital losses
Tax balances owing or refunds
Adjustments made to the return
Because capital losses can be carried forward indefinitely, the Notice of Assessment often acts as a record showing the amount available to offset future capital gains.
Capital loss carryback process
Applying a capital loss carryback generally requires additional documentation.
Investors who want to apply losses to previous years typically submit:
Form T1A (opens in a new tab): Request for Loss Carryback
This form may be included with the current income tax return or submitted afterward.
The CRA may then reassess the earlier tax return, adjusting previously reported taxable capital gains.
If the reassessment reduces tax previously paid, a refund may be issued.
Capital losses and adjusted cost base
Accurate calculation of adjusted cost base (ACB) can affect whether a gain or loss occurs.
ACB may include:
Original purchase price
Certain transaction costs
If multiple purchases of the same security occur over time, the adjusted cost base typically reflects the average cost per share.
Because ACB affects both capital gains and capital losses, accurate record-keeping can be important when reporting transactions.
Situations where capital losses may not apply
Certain transactions may affect whether losses can be used.
For example:
Losses realized in registered accounts, such as Registered Retirement Savings Plans (opens in a new tab) (RRSPs) or Tax Free Savings Accounts (opens in a new tab) (TFSAs) generally cannot be claimed.
Transactions involving related parties may trigger superficial loss rules, which can affect whether a loss is recognized for tax purposes.
These rules are outlined by the Canada Revenue Agency and may influence whether a loss qualifies as a net capital loss.
Capital losses and long-term investing
Over time, investment portfolios may experience periods of both gains and losses.
Historically, Canadian tax rules have allowed unused capital losses to remain available to offset future capital gains without a time limit.
Because capital gains taxation applies when assets are sold, losses realized in one year may interact with gains realized in later years.
In this context, capital loss carryforward in Canada may function as a mechanism that recognizes fluctuations in investment markets over longer time horizons.
6 Common mistakes Canadians make with capital loss carryforwards
Canadian tax rules allow net capital losses to be used to offset capital gains, either in previous years or in a future year. However, the process may involve several calculations and reporting steps within the income tax return. Based on guidance from the Canada Revenue Agency, certain misunderstandings may occur when investors track and apply unused capital losses.
Below are examples of situations that have been commonly referenced in CRA documentation and tax guidance.
Mistake #1: assuming losses offset salary or employment income
Some investors assume that capital losses may reduce other types of income, such as salary or employment income. Under CRA rules, net capital losses generally apply only to taxable capital gains. As a result, losses may typically be used to offset capital gains rather than other income sources.
Mistake #2: claiming losses from registered accounts (TFSA/RRSP)
Transactions that occur inside registered accounts may follow different tax treatment. Historically, capital losses generated within accounts, such as a TFSA or RRSP have not been deductible on a personal tax return, because gains in these accounts are generally not taxable.
Mistake #3: ignoring the superficial loss rule
The superficial loss rule may apply if an investor sells a security at a loss and repurchases the same or identical property within a defined time period. In such cases, the loss may not immediately qualify as a capital loss for tax purposes.
Mistake #4: miscalculating adjusted cost base (ACB)
Accurate adjusted cost base (ACB) calculations affect both capital gains and capital losses. Multiple purchases of the same security may change the average cost per share. Inaccurate ACB calculations could affect the amount of taxable capital gains or allowable losses reported.
Mistake #5: missing the 3-year carryback window
CRA rules allow capital loss carryback to apply losses to the three previous years. If a request is not made within the allowable timeframe, investors may rely on applying losses to future capital gains instead.
Mistake #6: claiming more losses than capital gains allow
Under Canadian tax rules, only allowable capital losses may be used against taxable income from capital gains, reflecting the inclusion rate applied to gains and losses. Because of this rule, reported losses may not exceed the amount of gains being offset in a given year.
Summary of capital loss carryforward Canada
Understanding capital loss carryforward in Canada may help investors interpret how losses from capital property interact with capital gains reported on an income tax return. Under current Canada Revenue Agency rules, net capital losses may be applied to taxable income from capital gains in previous years through a carryback or carried forward indefinitely to offset future capital gains.
Because the calculation involves elements, such as the adjusted cost base, the inclusion rate, and records from documents like the Notice of Assessment, outcomes may vary depending on individual tax situations and reporting details.
