CRA Reviews, Audits and Appeals
Sometimes the CRA checks your return — before it assesses it, after it assesses it, or years later in an audit. Most checks are routine and end with nothing changing. But if the CRA does change your return and you disagree, you have rights: a formal objection, an independent review, and ultimately the Tax Court of Canada. This guide explains the process. It is process navigation only — it gives no legal advice.
Your rights in one paragraph
If you disagree with an assessment or reassessment, you can file a notice of objection — for individuals, by the later of one year after the return’s filing deadline or 90 days after the date on the notice. The objection is reviewed independently by the CRA Appeals Division. If you still disagree, you have 90 days to appeal to the Tax Court of Canada.
Reviews: the routine check
A review is the CRA asking for proof of something on your return — a receipt, a slip, a document. Reviews can happen before the return is assessed (which delays any refund) or after. They are common, they are usually done by letter, and they usually end with the CRA accepting the claim once the documents arrive.
Answer a review promptly and send what was asked for. If you cannot find a document, say so and send what you have. Ignoring a review letter is the fastest way to turn a routine check into a reassessment.
Audits and reassessments
An audit is a deeper examination of your return, often covering more than one year. It can be done by correspondence or in person, and it ends with the CRA deciding whether your return was right. If it was not, the CRA changes it, and the change arrives as a Notice of Assessment or Reassessment.
Only a notice can be objected to — an assessment, a reassessment, a determination. A statement of account is not objectable, and neither is an auditor’s proposal letter. If you receive a proposal letter, respond to it with documents: a good response can prevent the reassessment entirely.
Filing a notice of objection
To dispute a notice, file a notice of objection. For individuals, the deadline is the later of one year after the return’s filing deadline, or 90 days after the date printed on the notice. Count from the date on the notice, not the day it reached you. Corporations and GST/HST objections get 90 days only.
You can file online in CRA My Account by choosing “Register my formal dispute”, or by mailing or faxing Form T400A, Notice of Objection: Income Tax Act, to the Appeals Intake Centre — or by sending a signed letter. GST/HST objections use Form GST159. Say which items you dispute, what you think the correct figure is, and why, and attach the documents that support you.
The Appeals Division and the Tax Court
Your objection goes to the CRA Appeals Division, which is separate from the auditor who assessed you and reviews the file independently. If the Appeals Division agrees with you, it adjusts the return and sends a reassessment. If it disagrees, it sends a Notice of Confirmation.
If you receive a Notice of Confirmation and still disagree, you have 90 days to file a Notice of Appeal with the Tax Court of Canada. If you missed the objection deadline, you can ask the CRA for an extension within one year after the deadline — you will need to show a reason for the delay, that you acted as soon as you could, and that your objection has merit.
Keeping records, and getting help
Keep the documents that support your return for six years from the end of the tax year. That is the period the CRA generally works within, and it is your proof if a review or audit comes.
If you need help with a dispute, a tax professional can advise you and can act as your representative. The Taxpayers’ Ombudsperson is a separate, independent office that deals with complaints about the service the CRA provided — not with disagreements about the tax itself, which go through the objection process above.
Sources: Canada Revenue Agency, guide P148; CRA, “File an objection: Income tax”; Income Tax Act, sections 165 and 166.1.