How CRA assesses your return — timelines and normal reassessment period
Assessment
Section 152 sets out how CRA assesses tax returns, the normal reassessment period (3 years for most individuals, 4 years for CCPCs), and the extended reassessment periods that apply to fraud, misrepresentation, and loss carryback requests.
Plain-language explanation
Section 152 governs the mechanics of CRA assessments — how and when CRA can assess or reassess your return.
Initial assessment: CRA initially assesses your return as filed (usually within 8 weeks for e-filed returns). The Notice of Assessment confirms the assessment or makes adjustments.
The normal reassessment period (NRP): CRA has 3 years from the date of the original assessment to reassess most individual taxpayers (4 years for CCPCs). After the NRP expires, CRA generally cannot reopen the year unless an exception applies.
Extended reassessment periods: - Misrepresentation or fraud (s.152(4)(a)): No time limit — CRA can reassess any year if the taxpayer made a misrepresentation attributable to neglect, carelessness, or wilful default, or committed fraud. - Loss carryback (s.152(6)): CRA can reassess a prior year to give effect to a loss carryback for up to 3 years after the year of the loss. - GAAR (s.152(4)(b.2)): The 2024 GAAR amendments extended the reassessment period by an additional 3 years in GAAR cases. - Waiver: Taxpayers can waive the NRP in writing (Form T2029), extending CRA's time to reassess — sometimes done for disputed objections in progress.
Taxpayer requests: Taxpayers can request an adjustment (T1-ADJ form) within 10 years of the original return. This allows correction of errors in your favour without filing a formal objection.
Example
Cara filed her 2023 T1 on April 29, 2024. CRA assessed it May 15, 2024. The NRP expires May 15, 2027. CRA discovers an error in 2028 — they cannot reassess (NRP expired) unless Cara made a misrepresentation (careless or fraudulent omission) in the return.
Amendment history
Significant changes to this provision. Older versions help you understand rules that applied in prior tax years.
GAAR reassessment period extended by 3 years. When GAAR is at issue in a reassessment, CRA now has the NRP plus an additional 3 years to reassess — for most individuals, up to 6 years total.
Before
GAAR assessments subject to normal 3-year NRP
After
NRP + 3 years (6 years total for individuals) when GAAR is in issue
Common questions
What is the statute-barred period for CRA to reassess me? +
3 years from the original notice of assessment for most individuals (4 years for CCPCs). After that, CRA cannot reassess unless you made a misrepresentation attributable to neglect, carelessness, willful default, or fraud. A "statute-barred" year is effectively closed.
Can I correct a mistake on my tax return after filing? +
Yes. File a T1-ADJ (Request for Adjustment) with CRA — available for the 10 most recent tax years. If you made a simple error (e.g., forgot to claim a deduction), a T1-ADJ is faster than a formal objection.
If I omit income carelessly, can CRA reassess after 3 years? +
Yes. S.152(4)(a) allows CRA to reassess at any time if there was a misrepresentation due to neglect, carelessness, or wilful default. "Careless" is a lower bar than "fraud" — forgetting to report significant income can be found to be careless neglect.
Key terms
Related sections
Source: Income Tax Act, RSC 1985, c. 1 (5th Supp.), section 152. — Read the official text on Justice Canada
These summaries are for educational purposes only and do not constitute legal or tax advice. Speak with a CPA for advice on your specific situation.