GAAR changes 2024: main purpose test, 25% penalty, 3 more years

What changed in the GAAR in 2024, and when each change applies

The amendments came in the Fall Economic Statement Implementation Act, 2023, which received royal assent on June 20, 2024 laws-lois.justice.gc.ca. The changes don't share one start date, so check the transaction date against each row.

The penalty date is the one people miss. The Act applies the penalty to transactions on or after the later of January 1, 2024 and royal assent, which is June 20, 2024 laws-lois.justice.gc.ca. A transaction your client closed in March 2024 faces the new purpose and substance tests but no GAAR penalty.

The main purpose test and the economic substance rule

For transactions before January 1, 2024, subsection 245(3) caught a transaction unless it "may reasonably be considered to have been undertaken or arranged primarily for bona fide purposes" other than getting the tax benefit laws-lois.justice.gc.ca. The new wording reverses the starting point. A transaction that produces a tax benefit is an avoidance transaction unless it "may reasonably be considered that obtaining the tax benefit is not one of the main purposes" laws-lois.justice.gc.ca. A strong commercial reason no longer settles it if the tax saving was also a main purpose.

Being an avoidance transaction still isn't enough. Subsection 245(4) still requires misuse of a provision or abuse of the Act read as a whole. The new 245(4.1) feeds into that step: if the transaction or its series is significantly lacking in economic substance, that is "an important consideration that tends to indicate" misuse or abuse laws-lois.justice.gc.ca. It is a weighting rule, not an automatic result.

The list in 245(4.2) is open ("may include, but are not limited to"), so a planning file should address all three factors in writing, not just the ones that look weak.

How the 25% GAAR penalty is calculated

Subsection 245(5.1) applies when GAAR is used on a transaction your client did not disclose under section 237.3 or 237.4. The penalty is (A + B) × 25%, minus C laws-lois.justice.gc.ca. A is the extra tax payable because GAAR applied. B is any amount that would have been deemed paid on account of Part I tax without GAAR but now isn't, such as a refundable credit the plan produced. C is any gross negligence penalty under 163(2) for the same transaction or series.

Worked example: a CCPC completes an undisclosed series in March 2025. The CRA applies GAAR and reassesses. Part I tax goes up $120,000, and a $10,000 amount the series would have had deemed paid on account of tax is denied.

The C offset stops the two penalties stacking in full; the gross negligence penalty page covers how that one is computed. Arrears interest on the extra tax runs separately at the CRA overdue interest rate. Subsection 245(5.3) brings the assessment, objection and collection rules of sections 152, 158, 159, 160.1 and 164 to 167 and Division J to the penalty laws-lois.justice.gc.ca, so it is assessed and disputed like tax.

The one exception to the penalty

Subsection 245(5.2) removes the penalty only if your client shows that, when the transaction was entered into, it was reasonable to conclude GAAR would not apply because the transaction or series was identical or almost identical to one that was the subject of published administrative guidance or statements by the Minister or another relevant government authority, or of one or more court decisions laws-lois.justice.gc.ca.

That is narrow. A favourable opinion letter, an aggressive reading of a case with different facts, or "everyone does this" doesn't meet it. In practice, disclosure is the reliable route: a transaction disclosed under 237.3 or 237.4 is outside 245(5.1) altogether.

Three more years to reassess, and how an RC312 removes them

Subparagraph 152(4)(b)(viii) lets the CRA reassess up to three years after the normal reassessment period when the reassessment gives effect to section 245, unless the transaction was disclosed under 237.3 or 237.4 laws-lois.justice.gc.ca. The normal period is three years from the original notice of assessment, or four for a mutual fund trust or a corporation other than a CCPC. The full list of extensions is on the CRA reassessment period page.

A transaction that isn't reportable or notifiable can still be disclosed. Under 237.3(12.1) your client may file an information return by its filing due date for the year the transaction occurs, and under 237.3(12.2) it may file up to one year late. A late filing still counts as on time for the penalty, but the extra reassessment window becomes one year instead of three laws-lois.justice.gc.ca. The prescribed form is RC312, which the CRA says covers "an optional filing under subsection 237.3(12.1)" canada.ca.

Worked dates for a CCPC with a December 31, 2025 year end and an original notice of assessment dated August 14, 2026:

If the transaction was reportable and the required RC312 was never filed, the exposure is worse. While the filing duty is unmet and the 237.3(8) penalty is unpaid, section 245 is read without subsection (4) for that transaction laws-lois.justice.gc.ca, so the CRA doesn't have to show misuse or abuse at all. The mandatory disclosure rules page has the filing deadlines.

What the preamble does, and what did not change

The new 245(0.1) says GAAR denies the tax benefit of avoidance transactions that misuse provisions or abuse the Act read as a whole, "while not preventing taxpayers from obtaining tax benefits contemplated by Parliament", and that it balances protecting the tax base against taxpayers' need for certainty laws-lois.justice.gc.ca. It doesn't create a new test. It tells a court how to read the rule.

Some things people file under 2024 are older. The tax benefit definition already covered a "reduction, increase or preservation of an amount" usable later, such as a loss pool, in the version in force from December 15, 2022 laws-lois.justice.gc.ca. And 245(7) still says GAAR tax consequences arise only through an assessment, reassessment or determination that applies the section laws-lois.justice.gc.ca.