How long does the CRA have to reassess my client's return, and when does it get longer?
In 2026, the CRA reassessment period is three years from the date on the original notice of assessment for individuals and CCPCs, and four years for other corporations, under ITA s.152(3.1). Certain cases add three years, fraud or careless misrepresentation removes the limit, and GST/HST gets four years from the later of the due date and filing date.
The normal reassessment period by taxpayer type
Subsection 152(3.1) sets the normal reassessment period: four years for a mutual fund trust or a corporation that isn't a CCPC, and three years for everyone else laws-lois.justice.gc.ca. GST/HST runs on its own clock under the Excise Tax Act
laws-lois.justice.gc.ca.
| Taxpayer | Normal period | Clock starts on | Rule |
|---|---|---|---|
| Individual (T1) | 3 years | Date the CRA sent the original notice of assessment | ITA 152(3.1)(b) |
| CCPC (T2) | 3 years | Date the CRA sent the original notice of assessment | ITA 152(3.1)(b) |
| Corporation that is not a CCPC at year end | 4 years | Date the CRA sent the original notice of assessment | ITA 152(3.1)(a) |
| Mutual fund trust | 4 years | Date the CRA sent the original notice of assessment | ITA 152(3.1)(a) |
| Other trusts (T3) | 3 years | Date the CRA sent the original notice of assessment | ITA 152(3.1)(b) |
| GST/HST registrant (net tax) | 4 years | Later of the return due date and the date the return was filed | ETA 298(1)(a) |
The income tax clock starts on the date the CRA sends the original notice of assessment, or an original notice that no tax is payable if that came first. It doesn't start at year end or on the filing date. The CRA's T2 page says the same thing in plain words: three years from the date it sent the original notice for a CCPC, four years if the corporation wasn't a CCPC at the end of the year canada.ca.
Two consequences catch people. A reassessment doesn't restart the clock, because the period is tied to the original notice. And a return that was never filed has no period running at all, since there is no original notice to count from.
Worked example: when the year actually closes
Your client filed a 2022 T1 on April 28, 2023, and the notice of assessment is dated May 15, 2023. The filing date doesn't matter. The normal period ends three years after May 15, 2023.
| Return | Notice of assessment | Normal period | Normal period ends | If an extended case applies |
|---|---|---|---|---|
| 2022 T1, individual | May 15, 2023 | 3 years | May 15, 2026 | May 15, 2029 |
| 2022 T2, CCPC | August 10, 2023 | 3 years | August 10, 2026 | August 10, 2029 |
| 2022 T2, corporation that is not a CCPC | August 10, 2023 | 4 years | August 10, 2027 | August 10, 2030 |
So as of October 2026, the individual's 2022 year and the CCPC's 2022 year are past the normal period. The CRA can still reach them only through one of the exceptions in 152(4). The corporation that isn't a CCPC stays fully open until August 2027.
When the CRA gets three more years
Paragraph 152(4)(b) lets the CRA reassess within three years after the normal period ends, but only for listed reasons laws-lois.justice.gc.ca. The CRA's T2 page lists the same cases
canada.ca.
| Situation | Extra time | Rule |
|---|---|---|
| Loss or credit carried back from a later year | 3 years | ITA 152(4)(b)(i) |
| Result of reassessing another taxpayer under 152(4)(b) or 152(6) | 3 years | ITA 152(4)(b)(ii) |
| Transaction with a nonresident the taxpayer does not deal with at arm's length, or foreign affiliate income | 3 years | ITA 152(4)(b)(iii) |
| Foreign income or profits tax paid or refunded | 3 years | ITA 152(4)(b)(iv) |
| Nonresident trust and foreign investment entity rules (sections 94, 94.1, 94.2) | 3 years | ITA 152(4)(b)(vii) |
| GAAR applied to a transaction not disclosed under 237.3 or 237.4 | 3 years | ITA 152(4)(b)(viii) |
| T1135 not filed or wrong, and foreign property income not reported | 3 years | ITA 152(4)(b.2) |
| Carryback year whose loss shrinks from a transaction with a related nonresident | 6 years | ITA 152(4)(b.4) |
The T1135 extension needs both conditions. Your client failed to report income from specified foreign property, and Form T1135 was not filed, filed late or filed inaccurately canada.ca. A late T1135 on its own, with the income reported, doesn't trigger it. The filing rules are on the T1135 filing requirements page.
Subsection 152(4.01) limits most extended reassessments to amounts that can reasonably be regarded as relating to the reason for the extension. Its list skips paragraph (b.2), so the T1135 extension is not confined to the foreign property income in the same way.
When there is no time limit
Subsection 152(4) opens with "at any time", and paragraph (a) has no end date. The CRA can reassess past the normal period where the taxpayer or the person who filed the return made a misrepresentation attributable to neglect, carelessness or wilful default, or committed fraud, or where the taxpayer filed a waiver within the normal period laws-lois.justice.gc.ca.
Even then, 152(4.01) limits the reassessment to what relates to the misrepresentation or to the matter named in the waiver. An error in rental expenses doesn't open the employment income on the same return.
Unreported real estate is the other open door. Under 152(4)(b.3), a disposition of real or immovable property that isn't reported on the return can be reassessed past the normal period, and the clock only starts when your client files an amended form reporting it: the CRA then has three years from that filing laws-lois.justice.gc.ca. The CRA's Schedule 3 page applies this to any sale of real estate left off the return
canada.ca, and nothing in 152(4)(b.3) carves out a principal residence.
If a client is sitting on an unreported year that the normal period hasn't protected, the Voluntary Disclosures Program is the route to look at before the CRA calls.
Waivers: Form T2029 and revoking with T652
A waiver keeps a year open for a named matter. The form is T2029, "Waiver in respect of the normal reassessment period or extended reassessment period" canada.ca. The CRA says to file it before the normal period expires, or within the extra three years for matters covered by the extended period
canada.ca.
A signed waiver gives the CRA more time on whatever it names. Describe the matter narrowly (one issue, one year), because 152(4.01) limits the reassessment to that matter and a broad description opens more of the return.
To end a waiver, file Form T652, Notice of Revocation of Waiver canada.ca. Under 152(4.1), the CRA can't reassess on the strength of the waiver after six months from the day the revocation is filed
laws-lois.justice.gc.ca.
The clock already stops while a taxpayer contests an information requirement or a compliance order in court: section 231.8 excludes that time from the reassessment period laws-lois.justice.gc.ca. As of October 2026, the CRA's T2 page also describes proposed changes, still before Parliament, that would stop it during a judicial review of any information requirement or while a new notice for failing to comply is outstanding
canada.ca. Check their status before relying on a year being closed.
GST/HST: four years from the later date
Under ETA 298(1)(a), the CRA has four years to assess net tax for a reporting period, counted from the later of the day the return was due and the day it was actually filed laws-lois.justice.gc.ca. A late return pushes the end date out.
| Reporting period | Return due | Return filed | Four years runs from | Period ends |
|---|---|---|---|---|
| Quarter ended December 31, 2022 | January 31, 2023 | January 20, 2023 | January 31, 2023 | January 31, 2027 |
| Quarter ended December 31, 2022 | January 31, 2023 | March 15, 2023 | March 15, 2023 | March 15, 2027 |
The same exceptions exist. Under 298(4), the limit doesn't apply where there was a misrepresentation attributable to neglect, carelessness or wilful default, fraud, or a waiver in effect. A GST/HST waiver is filed under 298(7) and specifies the matter, and 298(8) lets the registrant revoke it on six months' notice laws-lois.justice.gc.ca. The return deadlines are on the GST/HST filing deadline page.
Sources
Can my client ask the CRA to change a year that is past the normal period?
Yes, if the client is an individual (other than a trust) or a graduated rate estate. Under 152(4.2), the CRA can reassess to give a refund or reduce tax owing if the client applies within ten calendar years after the end of the year laws-lois.justice.gc.ca. A corporation doesn't get that window. If the CRA reassessed and your client disagrees, the notice of objection deadline is the date to watch.
Does a reassessment restart the three year clock?
No. Subsection 152(3.1) counts from the original notice of assessment, so a later reassessment or an adjustment request doesn't reset it laws-lois.justice.gc.ca. Each year closes on its own date.
Should my client sign the T2029 the auditor sent?
Only after you've checked that it names one matter and one year. Once the normal period ends, the waiver lets the CRA reassess only the matter it names, and your client can revoke it later with Form T652, which takes effect six months after filing canada.ca.
General information for the tax year shown, not advice for a specific client. Confirm the facts before you file or remit.