How to File a CRA Notice of Objection by Mail (Form T400A) in 2026

• A Notice of Objection is a formal dispute. You file one when you disagree with a CRA assessment, reassessment, or determination.
• The deadline runs fast. For individuals and testamentary trusts it is the later of 90 days after the date on your Notice of (Re)assessment, or one year after your filing due date for that return.
• You can file online or by mail. Use CRA My Account, or mail Form T400A or a signed objection letter to the Chief of Appeals at your Appeals Intake Centre.
• Send copies, not originals, of your supporting documents. Keep the originals.
• You generally do not have to pay the disputed amount while an individual objection is under review. The CRA normally holds off collecting until 90 days after it issues its decision. Some amounts, like payroll source deductions, are an exception.
• Keep proof of what you sent. A dated copy of your objection plus a dated PostPal mailing confirmation is a clear record, and you never leave the house for it.

You have 90 days. That is the part most people miss until it is almost gone. The minute a CRA Notice of Assessment or Reassessment lands and you think it is wrong, a clock starts, and the safest assumption is that you have 90 days from the date printed on that notice to file your objection. (Individuals sometimes get longer under the "later of" rule below, but treat 90 days as your working deadline and you will not be caught out.)

A Notice of Objection is the formal way to tell the Canada Revenue Agency you disagree with how it assessed your taxes. You file one after you receive a Notice of Assessment, Notice of Reassessment, or a determination and you think the CRA got it wrong: it disallowed a deduction or credit, added income you do not think is taxable, or hit you with a penalty.

Filing starts an independent review. Your file goes to the CRA's Appeals branch. An appeals officer who had nothing to do with the original assessment reads the facts, the law, and the documents you send, then confirms, varies, or reverses what was assessed.

One thing worth checking before you object. If the issue is a plain mistake or a missed slip, a quick call to the CRA or an adjustment request (a T1-ADJ, say) can fix it faster than a formal dispute. Save the objection for a real disagreement about how the law applies to you, when you want a reviewable decision that also keeps your right to appeal to the Tax Court of Canada open.

Work this out the day the notice arrives. For individuals (other than a trust) and graduated rate estates, the limit is the later of:

• 90 days after the date printed on your Notice of Assessment or Reassessment, or
• one year after your filing due date for the return in question.

You get whichever date falls later, so plenty of individuals end up with more than 90 days. Say your 2025 return was due April 30, 2026 and a reassessment shows up in March 2027. The one-year date is long gone, so your deadline is 90 days from that reassessment. But if the notice lands soon after you file, the one-year-after-filing date can hand you extra room. Calculate both. Use the later one. Do not eyeball it.

Everyone else gets the tighter version. Corporations and most trusts get 90 days flat from the date of the notice, no later-of cushion. Not sure which bucket you are in? The CRA spells out the time limits in Resolving your dispute: Objection and appeal rights under the Income Tax Act (P148).

Miss it and you are not finished, but you are on thin ice. You can apply for an extension of time. You have to do it as soon as you can and no later than one year after the original objection deadline passed, and you generally have to show you meant to object and had a reasonable reason for being late. Far easier to just hit the first deadline.

The CRA takes objections two ways. Pick one:

• Online: sign in to CRA My Account (or My Business Account) and use the "Register my formal dispute" service. Fastest route if your account is already set up.
• By mail: fill out Form T400A, Objection — Income Tax Act, or write a signed letter, and send it to the Chief of Appeals at your Appeals Intake Centre.

Mail makes sense when you have no CRA online access, when you are sending a thick stack of supporting documents that is easier on paper, or when you want a clean record of exactly what went in and when. The rest of this guide is about the mail route.

Two options, both valid. Fill out Form T400A, or write a signed letter that carries the same information the form asks for. The CRA accepts either. Whichever you choose, the objection has to include:

• Your full name and current mailing address.
• Your Social Insurance Number (SIN). Or your business number or trust account number, if that is what applies.
• A daytime telephone number so the appeals officer can reach you.
• The exact assessment in dispute: the tax year, and the date on the Notice of Assessment or Reassessment you are objecting to.
• The facts and reasons. Spell out what you disagree with and why. Name the amounts, and where you can, the rule or credit you are relying on.
• The relief you want. For example: "please allow the $4,200 in claimed medical expenses."
• Copies of supporting documents: receipts, statements, contracts, correspondence. Send copies, never originals. Keep the originals.
• Your signature and the date. An unsigned objection can be tossed.

One small thing that saves you grief: put your SIN on every page. Pages get separated in handling, and a page with your name but no SIN is a page that can go missing from your file. Beyond that, be specific and stick to facts. An objection that walks the officer through what happened, with documents attached and labelled, is far easier to decide your way than a vague gripe.

Writing a letter instead of using Form T400A? Or want a cover letter on top of the completed form? Here is a template to adapt. Swap the bracketed details for your own.

This does not go to your regular tax centre. It goes to the Chief of Appeals at the Appeals Intake Centre for your region. Send it to the wrong address and it has to be redirected, which burns days you do not have against the deadline.

We keep a verified, current address so you are not digging for it. See where to mail your CRA Notice of Objection and copy it exactly as listed.

You will not need to leave home to send it. Type or upload your objection and the supporting copies at postpal.ca/send. We print it, fold it into an envelope, and put it in the mail through Canada Post the next business day for about $6 flat. A dated mailing confirmation lands in your inbox. No printer, no envelopes, no trip out.

Once it arrives, your objection lands with the Appeals branch and gets assigned to an appeals officer. The officer works your file on their own, may call or write for clarification or more documents, and then issues a decision that confirms, varies, or cancels (vacates) the assessment.

How long this takes depends on the issue and the CRA's current backlog. A clean, simple objection might be done in a few months. A complex or high-dollar one can run a year or more. Files get worked roughly in the order they come in, so filing early and sending a complete, well-documented package keeps you out of the back-and-forth that drags things out.

Disagree with the decision they hand back? You generally get another 90 days from the date of that decision to appeal to the Tax Court of Canada. That right only exists because you filed a valid objection in the first place. That is the whole reason to do this properly.

The question everyone asks: do I pay while I wait? For individual income tax objections, the CRA normally holds off on collecting the disputed amount until 90 days after it sends its decision. A few things are exempt, like taxes you were required to withhold and remit. But interest keeps running on any balance that ends up upheld. So some people pay under protest to stop the interest clock while the objection stays alive. Your call.

Deadlines are the whole game here, so you want a record of what you sent and when. Two things, kept together, do the job:

• A dated copy of everything you mailed: your signed Form T400A or letter, plus copies of every enclosure. Save a PDF or keep a paper duplicate.
• Your PostPal mailing confirmation. When we mail your objection, you get a dated email showing the day it went out. Keep that email with your copy.

Put those two side by side and you can show you finished and sent your objection before the deadline. Stash them somewhere you can find them in thirty seconds. If a question about timing ever comes up, that paired record is what you point to.

Do I have to pay the amount in dispute while I object?

Usually not, for individual income tax objections. The CRA normally holds off collecting the disputed amount until 90 days after it issues its decision. Some amounts are exempt from that, like taxes you were required to withhold and remit. The catch is interest, which keeps running on anything ultimately confirmed. That is why some people pay under protest to stop the interest clock while the objection proceeds.

What if I miss the 90-day deadline?

Apply to the CRA for an extension of time. Do it as soon as you can, and no later than one year after the original objection deadline. You generally have to show you intended to object and had a reasonable explanation for being late. The sooner you move, the better your odds.

Can I file online instead of by mail?

Yes. File through CRA My Account or My Business Account using the "Register my formal dispute" service. Mail is the better fit when you have no online access, a pile of supporting documents, or you just want a clean paper record of what you submitted.

Do I have to use Form T400A?

No. The form is handy because it prompts you for everything the CRA wants. A signed letter is just as valid, as long as it carries your name, SIN, the assessment in dispute, and a clear statement of the facts and reasons.

Should I send original documents?

No. Send copies, keep your originals. The CRA does not return supporting documents, and you may need the originals if the dispute carries on to the Tax Court of Canada.

Where do I send my objection?

To the Chief of Appeals at the Appeals Intake Centre for your region, not your regular tax centre. We keep the current address on our where to mail your CRA Notice of Objection page.

How long will the CRA take to decide?

Depends on the issue and the CRA's current workload. Simpler objections, a few months. Complex or large disputes, a year or more. A complete, well-documented package keeps delays down.

None of this is hard. It is mostly about not letting the clock run out. Pin down your deadline with the later-of rule, lay out the facts and reasons plainly, attach copies of your documents, address it to the Chief of Appeals at the right Appeals Intake Centre, and hang on to a dated copy plus your mailing confirmation. Do that and you have a clean, on-time objection and a record to prove it.

When the package is ready, we handle the sending. Type or upload your objection and enclosures, and PostPal prints, envelopes, and mails them through Canada Post the next business day for about $6 flat, then emails you a dated confirmation for your records. No printer, no trip out.

Mail your CRA Notice of Objection with PostPal →

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