How do I file a Notice of Objection with CRA?

A Notice of Objection is the formal way to dispute a CRA assessment or reassessment under the Income Tax Act. For most individuals (and graduated rate estates), you have until the later of one year after the return's filing-due date or 90 days after the date on your Notice of Assessment or Reassessment. Other taxpayers, including corporations, have a flat 90-day deadline. For an income tax objection, you use CRA Form T400A, but a written letter that clearly identifies the assessment you are objecting to, the amounts you dispute, and the reasons for the dispute is also acceptable.

You can file your objection by mailing or faxing it to the Chief of Appeals at your regional tax services office, or through CRA My Account online (for individuals). The objection should set out, as clearly as possible, the facts you are relying on, the issues in dispute, and the relief you are seeking.

Once filed, your file is assigned to an Appeals Officer who is independent from the auditor. The officer reviews your objection and the audit file, may request additional information or documents, and then issues a decision — confirming, varying, or vacating the assessment. If you are unsatisfied with the outcome, you can appeal to the Tax Court of Canada. Do not miss the 90-day deadline; if you do, you must immediately apply for an extension.