- An individual, other than a trust, must serve a notice of objection by the later of one year after the filing-due date and 90 days after the notice of assessment was sent.
- After you object, the Minister must reconsider and vacate, confirm, vary or reassess, then tell you in writing.
- Collection of the disputed amount is generally barred while an objection is outstanding, but interest still accrues.
A notice of reassessment from the Canada Revenue Agency (CRA) is not necessarily the end of the matter. If you believe the CRA got it wrong, the Income Tax Act gives you a formal way to dispute it: a notice of objection.
This article covers who can object, the deadlines, what the CRA does after you file, and how collection works in the meantime. Deadlines are strict, so it is worth confirming your own dates with a lawyer or accountant.
This article covers Canadian federal tax law, which applies in every province.
Why the objection step matters
An assessment is deemed valid and binding despite any error, defect or omission, subject to being varied or vacated on objection or appeal. In other words, the assessment stands unless you challenge it through the proper process.
Before objecting formally, you can contact the auditor and, if the matter is not resolved, the auditor's team leader. The auditor can also estimate any amount owing before a notice is issued, which may help limit interest. How these conversations fit with your objection deadline depends on your situation, so it is worth confirming your dates with a lawyer or accountant.
Deadlines for serving a notice of objection
The deadline depends on who you are. The table sets out the rule in the Income Tax Act.
| Taxpayer | Deadline to serve the notice of objection |
|---|---|
| Individual (other than a trust) | The later of one year after the filing-due date and 90 days after the notice of assessment was sent |
| Other taxpayers | 90 days after the notice of assessment was sent |
The CRA gives you 30 days to agree or disagree with an auditor's written proposal after an audit, which is a separate step from the statutory objection deadline in the table. How the dates in your own case line up depends on your situation, so it is worth confirming them with a lawyer or accountant.
A large corporation faces an added requirement. Its notice of objection must describe each issue, the relief sought and the facts and reasons, and it can appeal only the issues so specified.
What to put in your objection
Be clear about what you dispute and why. A good objection identifies the tax year, the specific items you disagree with, the result you say is correct, and the facts that support you.
- The tax year and the notice of assessment you are objecting to.
- Each issue you dispute, listed separately.
- The facts and reasons behind your position.
- Supporting documents such as receipts, contracts, statements and calculations.
- Your contact details, and the details of any representative you have chosen.
You may choose a person to represent you and advise you on your tax affairs, but you remain legally responsible. The CRA's own forms and instructions for filing should be checked against the version current when you file.
What happens after you file
After an objection, the Minister must reconsider the assessment and vacate, confirm or vary it, or reassess, then notify you in writing. If a reassessment follows your objection, you can appeal without serving a new notice of objection.
If you are still unhappy, you can appeal to the Tax Court of Canada once the Minister confirms or reassesses, or 90 days pass with no decision. The appeal must be filed within 90 days of the notice of confirmation or reassessment.
Your rights during the process include freedom from reprisal. Complaining or asking for a formal review should not lead to reprisal, and a Reprisal Complaint can be filed on Form RC459.
Collection and interest while you dispute
For most assessments, the CRA may not start court proceedings, certify the debt or take listed collection steps until 90 days after the notice of assessment was sent. Subject to the exceptions below, if an objection is filed, collection of the disputed amount is barred until 90 days after notice of the Minister's confirmation or variation. If an appeal is filed, it is barred until the Tax Court's decision is mailed or the appeal is discontinued.
There are exceptions. These restrictions do not apply to amounts required to be withheld and remitted, such as payroll source deductions, and related penalties and interest. For a large corporation (taxable capital over $10 million), the Minister may collect half of an assessed amount within 90 days.
A taxpayer can avoid paying personal tax amounts in dispute until an impartial review, but interest still accrues and undisputed amounts must be paid. For 1 October to 31 December 2026 the prescribed rate on overdue income tax is 7%, and it changes quarterly.
What to do next
- Find the date the notice of assessment was sent and calculate your deadline.
- Work out which category you fall into in the table above.
- List the items you dispute and collect the supporting records.
- Pay any undisputed amount.
- Serve your notice of objection well before the deadline and keep proof of when and how you served it.
- Diarize the 90-day Tax Court appeal period that starts after the Minister's decision.
- Speak with a lawyer or accountant if the amount is large or the issues are complex.
Frequently asked questions
How long do I have to object to a CRA reassessment?
An individual other than a trust must serve the notice by the later of one year after the filing-due date and 90 days after the notice of assessment was sent. Other taxpayers have 90 days after the notice was sent.
Do I have to pay while my objection is being reviewed?
You can avoid paying personal tax amounts in dispute until an impartial review, but interest still accrues and undisputed amounts must be paid. Collection of the disputed amount is also generally restricted during that time, with exceptions such as payroll source deductions.
What if I lose my objection?
You may appeal to the Tax Court of Canada once the Minister confirms or reassesses, or 90 days pass with no decision. The appeal must be filed within 90 days of the notice of confirmation or reassessment.
Do I need a new objection if the CRA reassesses after I object?
No. If a reassessment follows your objection, you can appeal without serving a new notice of objection.
Sources
- Income Tax Act, s. 152(8) — Justice Laws (federal)
- CRA, Business audits — canada.ca
- CRA RC4188, What you should know about audits — canada.ca
- CRA, Taxpayer Bill of Rights — canada.ca
- CRA, Prescribed interest rates, Q4 2026 — canada.ca
- Income Tax Act, s. 165(1) — Justice Laws (federal)
- Income Tax Act, s. 165(1.11) and 169(2.1) — Justice Laws (federal)
- Income Tax Act, s. 225.1 — Justice Laws (federal)
Links go to official government, court and regulator pages. The law changes — confirm you are reading the current version.
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