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A tax assessment is the CRA’s calculation of your income tax for a year, and the paper (or online) summary of it is called a notice of assessment. It arrives after you file, and in most cases your return is processed right away. The notice is the document that tells you whether you’re getting money back, owing money or landing exactly at zero.
A notice of assessment (NOA) is the summary of the calculated amounts for your income tax and benefit return.
Notices of assessment: NOA or NOR, canada.ca
What is a notice of assessment, and where do I find mine?
Sign in to your CRA account. Once the return is processed, the notice is there, and you can also print past ones. If you didn’t sign up for online mail, the CRA sends a paper copy to the address it has on file. Keep every notice. Next spring you’ll want last year’s, and a preparer will ask for it.
Speed depends on how you filed. Electronic returns usually process faster than paper ones. Late filing, requested adjustments, several returns filed together and a CRA review can all slow things down. Returns from non-residents can take up to 16 weeks, according to the CRA’s notice page.
What’s on the assessment, line by line?
The page has your personal details, the tax year, an account summary showing a refund, a balance owing or a nil balance, and a detailed list of the amounts on each line. There’s also a NETFILE access code, made of eight letters and numbers, printed on the right side.
Your notice also carries your RRSP deduction limit, which is the number many people open it for. It’s the amount you can deduct for the next year, and going over it costs you. The RRSP calculator can show what a contribution up to that limit would save you.
Does the assessment match what you filed?
Compare it. Look at total income, deductions and credits and check them against your own return. If the CRA changed something, the notice should show it, and a change comes with an explanation. Grab your copy of the return, a highlighter if you like paper, and go line by line. Ten minutes at the kitchen table beats a letter six months later.
Here’s a way to test the last line. Say you earned $75,000 in Ontario and your T4 shows $13,000 of tax withheld. The tax refund calculator gives $12,704.65 of income tax for the year, so about $295.35 back. That’s an estimate that only counts basic credits, so a different figure on your notice doesn’t mean something went wrong. A gap of a few thousand dollars is another matter, so find out why before you do anything else.
| Document | What it tells you | Sent when |
|---|---|---|
| Notice of assessment | The result for the return you filed | After the return is processed |
| Notice of reassessment | An updated summary of changes to an assessed return | Only if something changes |
What if I disagree with my tax assessment?
You have 90 days from the date of the notice to register a formal dispute, per the CRA. Don’t wait until day 89 to start. Gather the slips or receipts that back up your position first, and see if a slip is missing from what you filed. If it is, ask the CRA to change the return.
A reassessment can follow the other way too. The CRA sends a notice of reassessment when changes are made to an assessed return, and those notices generally take about as long to process as a first assessment. If it’s the CRA that found the error, the reassessment is issued straight after it’s done.
Our guide to dealing with the CRA covers letters, reviews and payments if the disagreement turns into a longer back and forth.
What if the notice says I owe money?
If the account summary shows a balance, pay it quickly. For the 2025 return, the CRA charges interest compounded daily from the day after the due date, on any unpaid amount, including amounts that come from a reassessment. The rate changes every quarter. No rate is listed here, so check the CRA’s current prescribed rate before you plan a payment.
A late return has its own penalty. For 2025 it’s 5% of the balance owing plus 1% for each full month late, up to 12 months. And if you were penalized in 2022, 2023 or 2024 and got a demand to file, the penalty is 10% plus 2% a month for up to 20 months. Filing on time, even if you can’t pay yet, avoids that penalty. On a $1,000 balance filed three full months late, the first-time penalty alone would be $80 (5% plus 3 times 1%), before interest.
If your income is uneven and the balance keeps coming, look at the tax instalments calculator, which splits a payment into the four quarterly dates.
What this page is based on
Everything about notices, timelines and the 90 day objection window comes from the Canada Revenue Agency‘s notice of assessment page. Penalty rates come from its late-filing penalty page for the 2025 return, and the refund example is our own engine’s estimate. This site is not connected to the CRA, and only your own notice of assessment is official.
Frequently asked questions
What is a tax assessment?
It is the CRA's calculation of your tax for a year. The notice of assessment is the summary of it, sent after your return is processed.
How long do I have to object to an assessment?
90 days from the date on the notice, according to the CRA.
Where can I see my notice of assessment?
In your CRA account once the return is processed, or on paper if you didn't choose online mail.
What is a notice of reassessment?
An updated summary the CRA sends only when it changes an assessed return.
Why is my assessment taking longer than usual?
Late filing, adjustment requests, several returns filed together or a CRA review can slow processing. Paper returns are slower than electronic ones.
- How to file your tax return in Canada: steps and dates
What to gather, when your return is due and how to file in Canada, from the first slip to the notice of assessment that closes the year