- A Notice of Assessment ("NOA") is the CRA's official response to your filed tax return.
- A few sections deserve a closer look every year: 1.
- You generally have two starting options, depending on what's wrong: - A simple correction.
After you file a tax return, the CRA doesn't just file it away — it processes the return and sends you back a summary of what it decided. That document is called a Notice of Assessment, and for many Ontarians it's the only piece of tax paperwork they ever really look at closely. Understanding what it says, and what to check it for, can save you money and catch mistakes before they become bigger problems.
This guide explains what a Notice of Assessment actually is, walks through the sections worth reading carefully, and explains what your options are if something looks wrong.
What a Notice of Assessment Actually Is
A Notice of Assessment ("NOA") is the CRA's official response to your filed tax return. It confirms that your return has been processed and states the CRA's calculation of your income, deductions, credits, and the resulting balance — whether that's a refund owed to you or an amount you owe the CRA.
Importantly, an assessment is not the same thing as an audit. Most returns are assessed automatically or with light review, based largely on what you reported plus information the CRA already has on file (like T-slips submitted by employers and financial institutions). Receiving a Notice of Assessment doesn't mean the CRA has scrutinized every line of your return — it means the return has been processed and a result has been calculated.
If the CRA later revisits and changes that result, it issues a Notice of Reassessment instead, which follows the same format but reflects a revised calculation.
What to Check on Your Notice of Assessment
Don't just glance at the bottom line. A few sections deserve a closer look every year:
1. Does the reported income match what you filed?
Compare the income figures on the NOA against your own records and slips. A mismatch usually means either a slip you didn't include, a slip the CRA received that you didn't (or that arrived after you filed), or a data-entry issue.
2. Were your deductions and credits applied?
Confirm that deductions and credits you claimed — RRSP contributions, tuition, medical expenses, and so on — actually made it into the calculation. It's common for a claim to be denied or adjusted without the taxpayer noticing, especially when supporting documentation wasn't clear.
3. What's your RRSP contribution room and other carryforward balances?
Your NOA typically shows updated figures for things like RRSP deduction room and certain unused credits carried forward to future years. These numbers matter for planning next year's contributions and should be tracked from year to year.
4. Is there a balance owing, and by when is it due?
If you owe money, the NOA will show the amount. Interest can accrue on unpaid balances, so it's worth confirming the current amount and payment options promptly rather than setting the notice aside.
5. Are there any explanatory notes?
The CRA sometimes includes a short explanation when it adjusted a figure from what you reported. Read these carefully — they tell you exactly what changed and why, which is the fastest way to figure out whether the CRA made an error or you did.
If You Disagree With Your Notice of Assessment
You generally have two starting options, depending on what's wrong:
- A simple correction. If the issue is a missing slip, a math error, or something you can clearly document, you can typically request an adjustment to your return directly with the CRA rather than filing a formal dispute.
- A formal Notice of Objection. If the CRA has taken a substantive position you disagree with — denying a deduction, characterizing income differently than you did, or applying a rule you believe doesn't fit your facts — the next step is filing a Notice of Objection with the CRA's Appeals Branch. This is an administrative step, separate from and prior to any court proceeding.
Objection deadlines are strict and vary by taxpayer type. As of mid-2026, individuals (other than trusts) and graduated rate estates generally have until the later of one year after the return's filing-due date or 90 days after the Notice of Assessment or Reassessment is sent; other taxpayers, including corporations, generally have 90 days from the date the notice was sent. A late-objection request may be available within a further window after the regular deadline passes, but it isn't guaranteed. Because these rules and figures can change, verify the current deadline that applies to your situation before assuming you have time to spare.
If an objection doesn't resolve the dispute, the next step is an appeal to the Tax Court of Canada — a separate, judicial process that only becomes available after the objection stage.
Notice of Assessment vs. Notice of Reassessment: Quick Comparison
| Notice of Assessment | Notice of Reassessment | |
|---|---|---|
| When it's issued | After your original return is processed | After the CRA revisits and changes a prior assessment |
| What it means | First official calculation of your result | A revised calculation, which may increase or decrease what you owe |
| Common triggers | Routine processing of a filed return | Audit findings, matching-program discrepancies, or a taxpayer-requested adjustment |
| Your options if you disagree | Request an adjustment or file a Notice of Objection | File a Notice of Objection (subject to its own deadline) |
Frequently asked questions
How long does the CRA generally have to reassess my return after the original Notice of Assessment?
The CRA generally has a defined "normal reassessment period" that runs from the sending of the original Notice of Assessment, and it differs for individuals versus certain corporations. Outside that window, the CRA can typically only reassess if it can show misrepresentation due to neglect, carelessness, wilful default, or fraud, or if you've signed a waiver. Confirm the specific period that applies to your taxpayer type before assuming a past year is closed.
I lost my Notice of Assessment — can I get another copy?
Yes. Your Notice of Assessment is available through your CRA online account, and the CRA can also resend or reissue it on request. You don't need the original paper copy to access the same information.
Does a Notice of Assessment mean I'm being audited?
No. Assessment is the routine processing step that happens to essentially every filed return. An audit is a separate, more detailed review that only some returns receive, and being selected doesn't itself imply wrongdoing.
What if my Notice of Assessment shows a balance owing I can't pay right now?
The balance itself doesn't disappear if you can't pay immediately, and interest generally continues to accrue on the unpaid amount. Contact the CRA about payment arrangement options, and consider getting advice if the amount is disputed rather than simply unaffordable — those are different problems with different solutions.
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