How to File a Notice of Objection With the CRA Step by Step in Canada

If you received a notice of assessment or reassessment that you disagree with, a notice of objection is the formal way to ask the CRA to take a second look. The steps are straightforward, but the deadline is firm and the content matters.

This guide walks through what you can object to, when to file, what to include and how to send it. Details can vary with your situation, so a lawyer or accountant can confirm anything that is unclear.

This article covers Canadian federal tax law, which applies in every province.

Step 1: Confirm you can object

Objections can be filed against a notice of assessment, reassessment, determination or redetermination. The same rights apply to determinations such as the Canada child benefit, GST/HST credit, disability tax credit and loss determinations.

Some things cannot be objected to. You cannot object to a statement of account or an auditor's proposal letter. The CRA also lists examples such as RRSP or TFSA room statements, carryforward balances, Home Buyers' Plan balances, refund interest and nil assessments. You also cannot object to an issue on which you waived the right of objection in writing.

Penalties and interest are part of the assessment, so your objection can dispute them.

Step 2: Work out your deadline

An individual (other than a trust) has until the later of one year after the return's filing deadline and 90 days from the date of the notice. Corporations have 90 days. The count starts on the day the notice was sent.

Loss determinations and RRSP or TFSA over-contribution assessments have only a 90-day limit, even for individuals. Objections filed late or before the notice was issued may be invalid.

Step 3: Prepare the content

Your notice should contain the following:

• Your name, complete mailing address and daytime phone number.
• The notice date, tax year, and SIN, business number or other account number.
• The relevant facts and reasons, with copies of supporting documents.
• The representative's details, if you have one.
• Your signature and the date.

If you held back information during an audit or in response to a CRA request and give it only with your objection, the file may be sent back for a second review.

Step 4: Choose how to file

You can file online through My Account for Individuals or My Business Account by selecting "Register my formal dispute", and you receive a case number. A representative can file through Represent a Client. You can also send a form or signed letter by mail or fax to the Chief of Appeals, or deliver it in person.

The CRA says an objection submitted through a secure portal is assigned to an appeals officer sooner than paper. Mailed or faxed objections are received at the Appeals Intake Centre in Sudbury, Ontario.

Form T400A was cancelled as of 2026-10-26 and replaced with Form RC592, Notice of Objection. RC592 is a fillable PDF that must be downloaded and opened in Acrobat Reader 10 or later, not in a web browser.

After you file and what to do next

Once the CRA receives your objection, it gives a case number to use in all later correspondence. The Minister must reconsider the assessment and vacate, confirm, vary or reassess it, then notify you in writing.

Generally, you do not have to pay disputed income tax until the review is complete, though amounts you were required to withhold and remit must still be paid on time. Interest keeps accruing, and paying the disputed amount stops further interest on what you paid. Processing time varies with complexity.

• Note the date on your notice and count your deadline from it.
• Gather the reasons, facts and supporting documents.
• Choose a filing method and keep proof that you filed.
• Record your case number once you receive it.
• If you disagree with the result, check the 90-day window to appeal to the Tax Court.

Frequently asked questions