CRA Notice of Assessment: what it means and what to check
A Notice of Assessment is not a bill and it is not an audit. It is CRA telling you what it did with the return you filed, and it starts a clock you should know about.
What a Notice of Assessment is
When you file a return, CRA processes it and then issues a Notice of Assessment, often shortened to NOA. It confirms that the return was assessed, states whether you owe money or are getting a refund, and sets out anything CRA changed.
Getting one is normal. It is the ordinary end of the filing process, not a sign of a problem. What matters is reading it rather than filing it away, because the NOA is where CRA tells you if its view of your return differs from yours.
What to actually check on it
Start with whether the figures match what you filed. If CRA changed something, the notice explains what and why. Common corrections include instalment credits applied differently than you expected, a carryforward amount adjusted, or a deduction reduced.
Then check the balance. An NOA showing an amount owing carries interest from the original due date, not from the date on the notice, so a notice that arrives weeks after your deadline may already have interest running.
For a corporation, the assessment also confirms the instalment position for the coming year. That is worth reading before the first instalment date arrives rather than after. Our guide on corporate tax instalments covers how those are calculated.
Assessment, reassessment, and audit are three different things
An assessment is CRA processing your return as filed, with arithmetic and basic consistency checks.
A reassessment comes later and changes an assessment that was already issued. It arrives as a Notice of Reassessment, and it can be triggered by CRA reviewing something, by information from a third party, or by an adjustment you requested yourself.
An audit is an examination of your books and records. An audit can lead to a reassessment, but a reassessment does not mean you were audited. Most reassessments follow a desk review, not a field audit. Our guide on what triggers a CRA audit covers the difference in more detail.
The 90-day clock
If you disagree with an assessment, you have ninety days from the date on the notice to file a Notice of Objection. That date on the notice is what counts, not the date you opened the envelope or noticed the message in your account.
Ninety days sounds generous and passes quickly, particularly if the notice arrives while you are busy and you assume your accountant has seen it. If the amount is material and you think CRA is wrong, the objection is the mechanism, and missing the window makes the position much harder to change.
How long CRA can go back
CRA has a normal reassessment period during which it can reopen a year without needing to allege anything unusual. For individuals and Canadian-controlled private corporations that period is generally three years from the date of the original Notice of Assessment. For other corporations it is generally four years.
Those limits do not apply where CRA alleges misrepresentation attributable to neglect, carelessness, wilful default, or fraud, or where you have signed a waiver. In practice this is the reason to keep records for the full retention period rather than the length of the reassessment window. Our guide on how long to keep business records sets out the requirements.
Where to find your notices
Assessments and reassessments appear in My Business Account for corporate matters and in My Account for personal ones. If you have authorized a representative, they can see them too, which is the practical argument for having your accountant on the file. A notice that only arrives by mail to an old address is the most common way a ninety-day window quietly expires.
Common questions
What is a Notice of Assessment?
It is the document CRA issues after processing a return. It confirms the return was assessed, states whether you owe or are due a refund, and explains anything CRA changed from what you filed.
Is a Notice of Assessment the same as an audit?
No. An assessment is the ordinary processing of your return. An audit is an examination of your books and records. An audit can lead to a reassessment, but receiving an assessment or even a reassessment does not mean you were audited.
How long do I have to dispute a Notice of Assessment?
Ninety days from the date on the notice, by filing a Notice of Objection. The date printed on the notice is what starts the clock, not the date you received or read it.
How far back can CRA reassess?
The normal reassessment period is generally three years from the date of the original Notice of Assessment for individuals and Canadian-controlled private corporations, and generally four years for other corporations. Those limits do not apply where CRA alleges misrepresentation or where you have signed a waiver.
Where can I get a copy of my Notice of Assessment?
In My Business Account for corporate assessments and My Account for personal ones. An authorized representative can also access them on your behalf.
Does interest start from the date on the notice?
No. Interest on an amount owing runs from the original due date for the balance, not from the date the notice was issued, so a notice arriving after your deadline may already have interest accruing.
Sources
Want CRA correspondence handled by the firm that filed the return? See tax accountant, corporate tax, or business advisory.