To file a CRA notice of objection, you have until the later of two dates: 90 days from the date on your notice of assessment or reassessment, or one year after the filing due date for that tax year. You can file through My Account, on Form T400A, or with a signed letter to the chief of appeals. It costs nothing.
What a notice of objection is
It’s your formal statement that you disagree with an income tax assessment, reassessment, or determination. Once you file, the case goes to the CRA’s appeals area, which is separate from the office that issued the notice. A person there looks at your facts and the law again and decides whether the original result stands.
The right to object is set out in the Income Tax Act. You don’t need a lawyer or an accountant to use it, though some people hire one when the amounts are large or the issue is technical.
Objection or adjustment request
These are two different tools, and picking the wrong one wastes time.
An adjustment request (the online change service, ReFILE or Form T1-ADJ) fits when you left something out or made a mistake and you have the new information ready. You generally can ask to change a return from any of the last 10 calendar years. The CRA says waiting for an adjustment can be faster than an objection.
An objection fits when the CRA has looked at your return and reached a result you think is wrong, and you want that decision reviewed. Examples are a disallowed deduction, a credit removed after a review, or income added to your return.
The deadline is the catch. An adjustment request does not stop the objection clock. If you asked for an adjustment, are still waiting and the objection date is close, file the objection. If you already missed the date because you were waiting on an adjustment, an extension may still be possible (see below).
Before either one, call the number on your notice. Many disputes get resolved that way, says the CRA, and a short call sometimes shows a missing slip or a keying mistake.
The deadline, with examples
For an individual, the CRA says to file within the later of one year after the filing due date or 90 days after the date of the notice. Count from the date printed on the notice, not the day you opened it. Check your own notice rather than counting from memory. The CRA site describes the rule for corporations differently, so this article covers individuals only.
Example one. You file your 2025 return by April 30, 2026. The notice of assessment is dated June 10, 2026 and disallows a $4,000 deduction. Ninety days from June 10 is September 8, 2026. One year after the due date is April 30, 2027. The later date is April 30, 2027, so that’s your deadline.
Example two. A notice of reassessment for 2022 is dated November 20, 2026. One year after the 2022 due date (April 30, 2023) passed in April 2024. So the 90-day rule applies, and the deadline is February 18, 2027.
Reassessments of older years are where people get caught. The date on the new notice starts a 90-day count, and that’s all you get.
If you miss the deadline
You can ask the CRA to accept a late objection. The CRA says to apply as soon as possible, and no later than one year after the date you had to file the objection. You have to show that you applied as soon as you could. Past that one year, the door is closed.
Don’t count on this. It’s a request, and it can be refused. For related relief on penalties and interest, see our late filing penalty relief guide.
How to file
There are three routes, and all of them count the same.
- My Account: choose the option to file a formal dispute. You can also upload a completed T400A or a signed letter there. If you can’t get in, see the My Account sign-in and tracking guide.
- Form T400A, Notice of Objection, mailed or faxed to the chief of appeals.
- A signed letter to the chief of appeals, mailed or faxed.
Keep proof of when you sent it. The online confirmation, a courier receipt or a fax report all work. A mailed letter without a receipt is a risk if the date is close.
What to include
The CRA lists what your objection has to contain: your name, address and phone number, the date of the assessment and the tax year, your account number (your SIN for personal returns), and the relevant facts and reasons for your objection. Sign and date it, and attach supporting documents.
The reasons matter most. “This is wrong” gives the appeals officer nothing to work with. Say which line or amount you dispute, what you believe the right figure is, and why. If the CRA disallowed $4,000 of moving expenses, say what the move was, the dates, the distances, and attach the receipts and the lease or sale documents.
If you already sent documents to the CRA that were ignored, say so and send them again. Keep a copy of everything.
What happens next
The CRA gives your objection a case number. An appeals officer reviews it and may call or write to ask questions or request more papers. You can also ask for the documents the CRA used to support its assessment.
The CRA publishes average processing times for income tax objections by complexity, updated August 2026. Low complexity cases, such as personal credits, deductions or the Canada child benefit, average 145 days. Medium complexity, such as business expenses, averages 403 days. High complexity averages over 690 days. The CRA also says volumes are currently higher than normal. You can follow your file through the Progress Tracker in My Account, or call the objection enquiries line at 1-800-959-5513.
At the end, the CRA sends a decision. It may fully allow the objection, partly allow it, or confirm the original assessment.
Interest and collection while you wait
For most individuals, the CRA says it normally postpones collection action on the amounts in dispute until 90 days after it sends you its decision. That covers the disputed part only. Any amount you don’t dispute is still owed, and you should pay it on time.
Interest doesn’t stop, though. The CRA says interest continues to build during the objection period. If you win, the disputed amount is adjusted and you get the interest back on the part that was wrong. If you lose, you owe the tax plus the interest that built up. Some cases don’t get the collection pause, such as withheld taxes, so read the notice you get. If money is tight, ask the CRA about a payment arrangement. Our CRA notices guide explains what to expect from collections.
After the CRA decides
If you disagree with the decision, you have 90 days to appeal to the Tax Court of Canada. You can also appeal to the Court if the CRA hasn’t given a decision within 90 days of the day you filed your objection. Waiting is a choice, not a requirement, and many people let the appeals officer finish.
Timeline example. You file your objection on July 6, 2026. The CRA decision letter is dated March 3, 2027 and confirms the assessment. You have 90 days from that decision to go to the Tax Court, which is until June 1, 2027. If you don’t file by then, the assessment stands.
Court is a bigger step. There are court filing rules and procedures, so check the Tax Court of Canada’s own site before you decide. To see what an assessment change does to your bill, try the income tax calculator. Related tools: the Marginal Tax Rate & Tax Brackets calculator, plus all our tax calculators.
Sources
- CRA, Resolving your dispute: Objection rights under the Income Tax Act (P148)
- CRA, T400A Notice of Objection
- CRA, Processing times and complexity levels for objections
- CRA, Changing a tax return
Common questions
How long do I have to file a notice of objection?
Does it cost anything to file an objection?
Do I still pay the tax I dispute?
Can I go to Tax Court right away?
Last reviewed: . Figures come from the official sources listed above. How we check the numbers and our editorial policy.