How to Dispute a CRA Assessment: Notice of Objection and Tax Court

If the CRA has assessed or reassessed your return and you believe it is wrong, you are not required to simply pay and move on. The formal route is a Notice of Objection, reviewed by CRA Appeals, and after that an appeal to the Tax Court of Canada. This page walks through each stage; it is part of the Dealing with the CRA directory.

When a dispute is the right route

Correcting your own mistake is a different process: the T1-ADJ and “Change my return” guide covers it. For penalties and interest (not the tax itself), Form RC4288 asks the CRA to cancel them under the Taxpayer Relief provisions, which can be requested for the past 10 years; when that applies is covered in CRA payment arrangements and taxpayer relief.

Three levels of dispute

Step 1: Understand what you received

• Notice of Assessment (NOA): Issued after you file your return. If it shows a different amount than what you calculated, the CRA has changed something.
• Notice of Reassessment (NOR): Issued after an audit or review. The CRA has changed a previously accepted return; the usual reasons are covered in why the CRA reassessed your taxes.
• Notice of Confirmation: Issued after you file a Notice of Objection. The CRA reviewed your objection and is standing by its original position.

The deadline starts from the date printed on the NOA or NOR, not the date you open it.

Step 2: Gather supporting documents

Step 3: Informal resolution first

Before filing a formal objection, a call to the CRA can sometimes settle the issue:

The individual line is 1-800-959-8281 and the business line 1-800-959-5525; hours are on the CRA contact information page.

Step 4: File a Notice of Objection

Deadline

For an individual’s income tax return, you have the later of:

• 90 days from the date on the NOA or NOR, or
• One year from the due date of the return in question

For most people, the binding deadline is the 90-day window. For example, an NOA dated March 28 gives you until June 26 to file.

If the deadline is closing

If you miss the deadline, you can apply for an extension of time to file an objection under Income Tax Act subsection 166.1, within one year and 90 days of the NOA date. The CRA can grant it if you show:

• You had a bona fide intention to object within the original period
• There was a just and equitable reason for the delay (illness, family emergency, incorrect advice)

Extensions are discretionary. If the one-year extension is also missed, the Tax Court will hear extension requests only in limited circumstances. A timely objection with minimal detail is usually treated better than a detailed but late one, and you can supplement it with documents after filing.

Ways to file

In CRA My Account, the online route is under “Register a formal dispute”.

Required information

A vague objection (“I disagree with the amount”) without specifics is harder to win.

Sample objection letter

[Your Name]
[Your Address]
[City, Province, Postal Code]

Date: [Today's Date]

Canada Revenue Agency
[Appeals Intake Centre address]

Re: Notice of Objection
    Tax Year: [Year]
    SIN: XXX-XXX-XXX

I hereby file a Notice of Objection to my Notice of [Re]assessment
dated [date] for the [year] tax year.

Issue: [e.g., Disallowed medical expense deduction of $5,000]

Facts:
[Describe the situation clearly]

Reasons:
[Explain why you believe your position is correct,
referencing tax law if applicable]

Enclosed: [List supporting documents]

I request that you vacate/vary the assessment as follows:
[What you want CRA to do]

Sincerely,
[Your signature]
[Your printed name]

Where to send a mailed objection

Mailed Notices of Objection go to one address, the Appeals Intake Centre in Sudbury: Appeals Intake Centre, 1050 Notre Dame Avenue, Sudbury ON P3A 5C1. Faxed ones go to an Eastern or a Western fax line depending on where you live; both lines are in Appendix B of the CRA’s guide P148.

Addresses can change, so check the current ones on the CRA website. These are Appeals addresses, not the tax centres that process returns; those are listed with the CRA tax-centre addresses.

Step 5: The Appeals review

Once your objection is filed, CRA Appeals, a division independent of the auditors who issued the reassessment, will:

1. Send an acknowledgment of your objection
2. Assign an Appeals Officer to your file
3. Review the file independently

The Appeals Officer may contact you by phone to discuss the issues, request additional documentation, or schedule a conference call with you and your representative.

Possible outcomes

Collections while you dispute

The hold applies to the disputed amount; an undisputed balance can still go to collections, which are covered in what happens if you don’t pay the CRA, and can be spread out with a payment arrangement.

Step 6: Tax Court of Canada

If the CRA confirms the reassessment and you still disagree, the next step is the Tax Court of Canada.

Two procedures

Informal Procedure

• For disputes where federal tax and penalties total $25,000 or less (per tax year)
• Faster, less formal, and designed for self-represented taxpayers
• No formal pleadings required; you file a simple Notice of Appeal
• Hearings are held in cities across Canada
• There is no filing fee for the Informal Procedure (filing fees of $250-$550, depending on the amount in dispute, apply only to the General Procedure)
• Representation by yourself, an accountant or a lawyer

General Procedure

• Required for disputes over $25,000 (or when you choose it for smaller amounts)
• Formal litigation process: pleadings, examinations for discovery, legal arguments
• In practice requires a tax lawyer
• The losing party may be ordered to pay the other side’s legal costs

Filing in Tax Court

File your appeal at: Tax Court of Canada, 200 Kent Street, Ottawa ON K1A 0M1, or through the online portal at tcc-cci.gc.ca. The Notice of Appeal includes:

• Your name, SIN, and address
• The year(s) under dispute
• A description of the assessment you are appealing
• The facts and legal arguments you rely on
• What relief you are requesting (reduce the assessment, cancel penalties, etc.)

Professional help and typical costs

Service complaints vs disputes

The Taxpayer Bill of Rights covers being treated professionally, privacy, complete information, consistent application of the law and the right to a formal dispute. The Taxpayers’ Ombudsperson handles service complaints (delays, an unresponsive CRA, conduct), not the amount of an assessment.

Errors you made yourself

If the issue is not a disagreement with the CRA’s assessment but an error you made (unreported income, missed foreign income, an incorrect deduction), the Voluntary Disclosures Program (VDP) may fit better than a dispute: it is for taxpayers who come forward to correct past returns. How it works now, with prompted and unprompted applications, is covered in the CRA voluntary disclosure guide. Appeals of benefit decisions (EI, CPP, OAS) are a separate process, covered in how to appeal a benefit denial.

Related CRA guides

• Responding to a CRA audit or review letter: before a reassessment is issued
• Checking whether you owe the CRA: the balance a reassessment leaves