Quick answer: If CRA reassesses your TFSA activity as business income, every realized gain is added to your taxable income at full marginal rates — not the 50% capital-gains rate. Interest accrues from the original tax year, and gross-negligence penalties may apply.
What this means: A high-six-figure TFSA reassessed across three years can produce a tax bill larger than the account itself, especially in higher provinces. The taxpayer is liable, not the brokerage.
What to do next: See whether your activity sits in the high-risk zone before the next filing. Run the risk check →
If the CRA decides a TFSA was carrying on a business of trading securities, it issues a notice of reassessment to the TFSA trust under paragraph 146(4)(b) of the Income Tax Act. The trust is then liable for tax on the trading income at the top federal marginal rate plus the relevant provincial top rate. The holder, as trustee of the TFSA, receives the assessment and is generally liable for any unpaid amount under section 160. Interest accrues from the original filing deadlines.
The reassessment timeline
| Stage | What happens | Typical timing |
|---|---|---|
| 1. Initial inquiry letter | CRA requests broker statements, transaction history, the holder’s outside trading activity, and the holder’s occupation. | 30 days to respond |
| 2. Proposal letter | CRA proposes a reassessment with the figures it intends to apply, and explains the basis (the Folio S3-F9-C1 factors). | 30 days to respond |
| 3. Notice of (re)assessment | CRA issues a notice to the TFSA trust setting out tax owing, interest, and any penalties. | Issued after proposal review |
| 4. Notice of objection | The holder, as trustee, can object within 90 days of the assessment date. | 90-day window |
| 5. CRA Appeals review | An appeals officer outside the original audit reviews the file and may confirm, vary, or vacate. | Several months to over a year |
| 6. Tax Court of Canada | If still in dispute, the holder can appeal to the Tax Court within 90 days of the appeals decision (or 90 days after objection if no decision issued in 180 days). | 1 to 3 years through the General Procedure |
What the reassessment actually charges
The reassessment treats the TFSA trust as the taxpayer. Trading profits are taxed as business income at the top federal marginal rate of 33 percent and the top provincial rate, with no graduated brackets. Capital gains attributable to the business are taxable at 100 percent inclusion (because business gains are on income account, not capital account). The trust is not entitled to the lifetime capital gains exemption or to most personal credits. Interest compounds daily from the original filing deadlines for each tax year.
How CRA finds these accounts
TFSA issuers file an annual information return reporting year-end fair market value, contributions, and withdrawals. CRA’s screening picks accounts where:
- Year-over-year growth is far higher than contributions can explain.
- The holder has industry knowledge (broker, adviser, financial industry employee).
- The same name appears in audit files for similarly structured non-registered accounts.
- Trading patterns visible from third-party sources suggest active strategies.
Worked example: how the numbers shake out
A self-directed investor’s TFSA grows from $25,000 of contributions made between 2018 and 2024 to $480,000 by the end of 2025, after roughly 600 trades a year in penny stocks and small-cap names. CRA reassesses the 2022 to 2025 tax years. The trust is found to be carrying on a business.
- Net trading profits for 2022 to 2025: $360,000 (illustrative).
- Federal tax at 33 percent: $118,800.
- Provincial tax at top rate (Ontario, 13.16 percent): $47,376.
- Combined tax: roughly $166,000 before interest and penalties.
- Interest and arrears interest accrue daily from the filing deadline of each year.
The holder pays this tax personally as trustee. There is no shielding from the TFSA wrapper for business income.
What can defeat a TFSA business reassessment
A holder challenging a reassessment usually argues some combination of:
- Frequency and time spent are not at the level required to constitute a business.
- Holding periods are longer than CRA characterized them.
- The holder has no industry knowledge or financing.
- The trading strategy was passive (e.g., dollar-cost averaging) rather than active.
- CRA’s calculations of net profit are wrong (e.g., did not net losses).
Showing that the activity does not satisfy several of the Folio factors is more persuasive than disputing one. Tax Court of Canada decisions including Ahamed v The King 2023 TCC 17 have shown that the test is multifactor and fact-intensive.
What this does not cover
- Excess contribution tax of 1 percent per month.
- Non-qualified investment tax of 50 percent of FMV.
- Advantage tax of 100 percent of advantage value.
- These can stack on top of business-income tax in the same audit.
Cross-references
- CRA Notice of Objection: How to File and the 90-Day Deadline
- Taxpayer Relief: Cancelling CRA Penalties and Interest
- Voluntary Disclosures Program: Fix Past Tax Mistakes
- Can CRA Tax Your TFSA?
- How Many Trades Are Too Many in a TFSA?
Frequently asked questions
- What happens when CRA reassesses a TFSA for day trading?
- CRA issues a notice of reassessment to the TFSA trust under paragraph 146(4)(b). The trust is taxed at the top federal marginal rate plus the relevant provincial top rate. The holder is liable as trustee.
- How far back can CRA go on a TFSA reassessment?
- Generally three or four years from the original assessment date, but the period is unlimited if CRA establishes misrepresentation attributable to neglect, carelessness, wilful default, or fraud.
- What is the tax rate on TFSA business income?
- Top federal marginal rate of 33 percent plus the relevant provincial top rate. Combined rates range roughly from 44 to 54 percent depending on province.
- How long do I have to object to a TFSA reassessment?
- 90 days from the date on the notice of (re)assessment. Objections are filed using Form T400A or through CRA My Account.
- Are losses in a TFSA used to offset business income on reassessment?
- Yes, in computing net business profit for the trust. Losses are not deductible against the holder's other income outside the TFSA.
- Does the holder pay interest and penalties personally?
- The holder pays as trustee. Interest accrues daily from the original filing deadlines. Penalties may apply where CRA establishes misrepresentation.
- Can I keep contributing to my TFSA during a reassessment?
- Yes. The reassessment does not freeze contribution room. Continued day-trading patterns can extend the audit to additional tax years.