What to Include in a Notice of Objection Letter to the CRA in Canada

If you disagree with a CRA assessment, you can write your own objection. A clear, complete letter helps the Appeals officer see what you are disputing and why.

This article covers what the Income Tax Act and CRA guidance say belongs in the notice, which documents to attach, and where to send it.

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

What the law requires at a minimum

A taxpayer who objects to an assessment must serve a written notice of objection setting out the reasons for the objection and all relevant facts. So a one-line letter saying "I disagree" is not enough.

Check first that what you have is something you can object to. You can object to a notice of assessment, reassessment, determination or redetermination. You cannot object to a statement of account or an auditor's proposal letter. CRA also lists items that cannot be objected to, including RRSP or TFSA room statements, carryforward balances, Home Buyers' Plan balances and nil assessments.

The details to put in the letter

CRA guidance says a notice of objection should contain the following:

• Your name, complete mailing address and daytime phone number.
• The notice date and the tax year.
• Your 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, with an authorized officer signing for a corporation or trust.

If you have an authorized representative such as an accountant, the notice should include their name and address.

Writing the facts and reasons

Explain each item you dispute separately. State what the assessment did, what you say is correct, and the facts that support you. Refer to the documents you attach, such as receipts, contracts, statements or correspondence.

Penalties and interest are part of the assessment, so your notice can dispute them. A request that the CRA cancel or waive them as a matter of fairness is separate and is not an objection.

Include everything you have. If you withheld 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.

Be careful if you ever signed a waiver. You cannot object to an issue on which you waived the right of objection in writing.

Large corporations have extra requirements. They must reasonably describe each issue, state the relief sought as a change in a balance or undeducted amount, and give the facts and reasons for each issue.

The form, and how and where to file

CRA's page says Form T400A was cancelled as of 2026-10-26 and replaced by 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. You can also send a signed letter, so check the current CRA instructions before choosing.

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.

Deadlines and what to do next

Individuals (other than trusts) generally have until the later of one year after the filing-due date and 90 days after the notice of assessment was sent. The exception is loss determinations and RRSP or TFSA over-contribution assessments, which have only a 90-day limit, even for individuals. Corporations have 90 days. The count is from the day the notice was sent, not received. Objections filed late, or before the notice was issued, may be invalid.

• Confirm what type of notice you have and its date.
• Work out your deadline before you start writing.
• Collect supporting documents and make copies.
• Write the facts and reasons clearly, item by item.
• Sign and date the notice.
• Keep the case number CRA gives you and use it in all later correspondence.
• Ask a lawyer or accountant to review the draft if a lot of money is involved.

Frequently asked questions