Every year, millions of Canadians file their tax returns and then wait for the Canada Revenue Agency’s response. That response comes in the form of a Notice of Assessment (NOA) — a document that most taxpayers glance at, file away, and forget about. That is a costly mistake.

Your NOA is not just a receipt confirming the CRA received your return. It is the CRA’s official position on your tax situation for the year. It tells you whether the CRA agrees with what you reported, how much you owe or are owed, and what your key contribution limits are for the year ahead. If there is a discrepancy — and there often is — the NOA is where you will find it.

At Insight Accounting CPA, we review every client’s Notice of Assessment line by line. Our Accounting Intelligence systems flag discrepancies automatically, but understanding what your NOA says — and what to do when something looks wrong — is knowledge every Canadian taxpayer should have.

Here is the complete guide for 2026.

What Is a Notice of Assessment?

A Notice of Assessment is the official document the CRA issues after processing your income tax return. It is typically issued within two to eight weeks of filing electronically (longer if you file by paper). The NOA serves several critical functions:

Confirms your filing has been processed. The CRA has received and reviewed your return.
States whether the CRA agrees with your reported amounts. If they have made adjustments, those adjustments will appear on the NOA.
Calculates your refund or balance owing. This is the bottom line most people look at first.
Sets your RRSP deduction limit. Your NOA is the authoritative source for how much you can contribute to your RRSP for the following year.
Starts the clock on your objection rights. You have 90 days from the date on your NOA to file a formal objection. Miss this deadline and your options become significantly more limited.

The NOA is a legal document. If you disagree with the CRA’s assessment, the 90-day objection window begins the moment the NOA is dated — not when you receive it, not when you read it, and not when your accountant reviews it.

How to Access Your NOA in 2026

There are three ways to get your Notice of Assessment:

CRA My Account (Fastest) Log in to your CRA My Account at canada.ca. Navigate to “Tax Returns” and then “Notice of Assessment.” Your NOA is typically available here within two weeks of e-filing. Starting in 2026, the CRA has enhanced its multi-factor authentication requirements for My Account access, so ensure your security credentials are up to date.

By Mail If you have not signed up for online mail, the CRA will send your NOA by Canada Post. This takes four to six weeks from the filing date. Paper NOAs are identical in content to the online version.

Through Your Tax Professional If your CPA or tax preparer filed your return using EFILE, they can often access your NOA status through the CRA’s Represent a Client portal. At Insight Accounting CPA, we monitor NOA releases for all clients and flag any unexpected adjustments immediately.

How to Read Your Notice of Assessment: Section by Section

Your NOA is structured in a specific order. Here is what each section means and what to look for.

1. Personal Information and Assessment Date

The top of your NOA shows your name, address, social insurance number (partially masked), and the tax year being assessed. The assessment date is critical — it is the date from which your 90-day objection period begins.

What to check: Verify your personal details are correct. An incorrect address can cause future correspondence to go astray. If your SIN appears incorrect, contact the CRA immediately.

2. Summary of Assessment

This is the section most taxpayers look at first. It shows:

Total income assessed: The CRA’s calculation of your total income for the year, based on the information slips they have on file (T4s, T5s, T3s, etc.) and what you reported.
Taxable income: Your total income minus allowable deductions (RRSP contributions, union dues, childcare expenses, etc.).
Total federal tax: The federal tax calculated on your taxable income.
Total provincial tax: For Ontario residents, this includes Ontario tax, the Ontario surtax (if applicable), and the Ontario Health Premium.
Total tax payable: Combined federal and provincial tax.
Total credits applied: All credits and payments, including tax withheld at source, quarterly instalments, and refundable credits like the GST/HST credit.
Refund or balance owing: The final number — what the CRA owes you, or what you owe the CRA.

What to check: Compare the “total income assessed” on your NOA to the total income on the tax return you filed. If these numbers differ, the CRA has made an adjustment. This is the most common area where discrepancies appear.

3. Explanation of Changes and Other Information

If the CRA has adjusted any amounts from what you reported, this section explains why. Common adjustments include:

Unreported income: The CRA cross-references your return against information slips from employers, banks, and investment firms. If a T4 or T5 slip was not included on your return, the CRA will add that income.
Disallowed deductions or credits: If the CRA does not accept a deduction you claimed (common with home office expenses, moving expenses, or medical expenses), the disallowed amount and reason will appear here.
Recalculated credits: If the CRA determined your GST/HST credit, Canada Child Benefit, or other income-tested benefits should be different from what you expected, adjustments appear in this section.

What to check: Read every line in this section carefully. If the CRA has made changes you do not understand, do not ignore them. Contact your CPA or the CRA for clarification.

4. RRSP Deduction Limit Statement

Your NOA includes your RRSP deduction limit for the upcoming contribution year. This is calculated as 18% of your previous year’s earned income (up to the annual maximum of $32,490 for the 2025 tax year, reported on your 2025 NOA), plus any unused contribution room carried forward, minus any pension adjustments.

What to check: If your RRSP limit seems lower than expected, check whether your employer reported a pension adjustment (PA) on your T4. PAs reduce your RRSP room. If you have unused room from prior years, confirm the carryforward amount matches your records.

5. Account Balance

The final section shows your overall account balance with the CRA, including any amounts from prior tax years. If you owe money from previous assessments, those amounts may appear here along with interest charges.

What to check: If the balance does not match what you expected, it may include amounts carried over from a prior year’s reassessment, instalment interest, or penalties. Do not assume your current year refund was simply reduced — check why.

Common Reasons the CRA Adjusts Your Return

Understanding why adjustments happen helps you prevent them in future years. The most frequent reasons include:

Missing information slips. You forgot to include a T5 from a bank account or a T4A from a contract. The CRA matches every slip issued in your name against your return. With over 700 million information slips processed annually, their matching system is comprehensive.

Math errors. Simple calculation mistakes on your return. E-filing virtually eliminates this issue, but it still occurs with paper returns.

Ineligible claims. Claiming a deduction or credit you do not qualify for — such as the first-time home buyer’s credit when you have owned property within the previous four years, or medical expenses that fall below the threshold.

Reassessment of prior years. Sometimes the CRA reassesses a prior year, which changes carryforward amounts (like capital losses or tuition credits) that affect your current year assessment.

CRA matching programs. The CRA’s Accounting Intelligence systems — yes, they use AI too — cross-reference property records, vehicle registrations, and other databases against reported income to identify potential unreported income.

What to Do If You Disagree with Your NOA

If your NOA contains adjustments you believe are incorrect, you have several options. The key is to act quickly — the 90-day deadline is firm.

Step 1: Verify the Discrepancy

Before filing a formal objection, confirm that the CRA’s adjustment is actually wrong. Pull your original return, gather your supporting documents, and compare them to the NOA. Sometimes what looks like an error is actually a legitimate adjustment you overlooked.

Step 2: Call the CRA or Contact Your CPA

For simple issues — a missing information slip you can now provide, or a clear data entry error — a phone call to the CRA’s individual inquiries line (1-800-959-8281) may resolve the issue without a formal objection. Your CPA can also contact the CRA on your behalf through the Represent a Client service.

If you do not have a CPA reviewing your return, consider working with a professional for personal tax planning to avoid similar issues in future years.

Step 3: File a Notice of Objection (T400A)

If the issue cannot be resolved informally, you must file a Notice of Objection within 90 days of your NOA date. You can do this:

Online through CRA My Account under “Register a Formal Dispute”
By mail using Form T400A, sent to the Chief of Appeals at your regional tax services office
Through your CPA who can file on your behalf via Represent a Client

Your objection must clearly state the facts and reasons why you disagree. Include all supporting documentation — receipts, contracts, bank statements, information slips — with your initial filing. The more complete your objection, the faster it will be resolved.

Step 4: The Appeals Process

Once you file an objection, the CRA’s Appeals Division reviews your case independently from the original assessor. Processing times vary, but the CRA targets resolution within 180 days for most objections. During the appeal, you generally do not need to pay the disputed amount, though interest may continue to accrue.

If the Appeals Division rules against you, your next option is the Tax Court of Canada, which is an independent judicial body. This is where having a CPA or tax lawyer becomes essential.

Step 5: Request a Deadline Extension (If You Missed the 90 Days)

If you missed the 90-day deadline, you can apply to the CRA for an extension under subsection 166.1 of the Income Tax Act. You must apply within one year of the original deadline and demonstrate that you had a reasonable inability to act within the normal period. Extensions are not guaranteed — the CRA grants them at their discretion.

Special Considerations for Business Owners

If you operate a sole proprietorship or small corporation, your NOA may include adjustments related to business expenses, capital cost allowance (CCA), or GST/HST amounts. Business-related disputes are typically more complex and involve larger dollar amounts.

For corporate returns, the NOA equivalent is the Notice of Assessment for the T2 return. The same 90-day objection window applies, but the stakes are often higher. If your corporation is facing a CRA reassessment, professional representation through a corporate tax planning advisor is not optional — it is essential.

Business owners who have fallen behind on filing and are now dealing with estimated assessments from the CRA should consider catch-up filing services to bring all outstanding returns current before addressing individual NOA disputes.

Frequently Asked Questions

How long does it take to receive my NOA after filing? If you file electronically, your NOA is typically available in CRA My Account within two weeks. Paper filers may wait four to eight weeks. During peak tax season (March through June), processing times may be slightly longer.

Is my NOA the same as my tax return? No. Your tax return is what you file with the CRA. Your NOA is the CRA’s response — their assessment of what you filed. They may agree with everything you reported, or they may make adjustments.

What if my RRSP deduction limit on the NOA is wrong? Contact the CRA or your CPA. Common causes include unreported pension adjustments, a missing prior-year return that affects carryforward amounts, or an employer error on a T4 slip.

Can the CRA reassess my return after issuing the NOA? Yes. The CRA can reassess your return for up to three years after the original NOA date (the “normal reassessment period”). For cases involving fraud or misrepresentation, there is no time limit.

Do I have to pay the balance owing while I dispute my NOA? Generally, yes — the assessed amount is payable by the filing deadline regardless of a dispute. However, you can request the CRA hold collection action while your objection is under review. Interest continues to accrue on unpaid balances.

What happens if I ignore my NOA? Ignoring your NOA does not make it go away. If you owe money, the CRA will add interest and may eventually take collection action including garnishing wages or freezing bank accounts. If the CRA made errors in your favour, you lose the opportunity to correct them after the 90-day objection window closes.

Do Not Leave Money on the Table

Your Notice of Assessment is one of the most important tax documents you receive each year. It deserves more than a glance. Every line represents the CRA’s position on your tax situation — and the CRA does not always get it right.

At Insight Accounting CPA, our Accounting Intelligence platform automatically cross-references every client’s NOA against their filed return, flagging discrepancies the moment the assessment is released. We catch what others miss — an average of $23,000 in missed deductions per client.

If you have received a Notice of Assessment you do not understand, if the CRA has made adjustments you disagree with, or if you simply want a professional review of your tax situation to ensure you are not overpaying, we can help.

Book a free consultation with Insight Accounting CPA — and let us make sure the CRA has your numbers right.

Bader A. Chowdry, CPA, CA, LPA, is the founder of Insight Accounting CPA, serving businesses and individuals across Mississauga, Toronto, and the Greater Toronto Area. With a patent-pending AI Governance Framework and deep expertise in CRA disputes and tax optimization, Bader and his team deliver Accounting Intelligence that finds what others miss.

CRA Notice of Assessment Explained 2026: How to Read Your NOA and What to Do If You Disagree

What Is a Notice of Assessment?

How to Access Your NOA in 2026

How to Read Your Notice of Assessment: Section by Section