CRA Notice of Reassessment 2026: Objection Deadline & How to Push Back

You filed your T1 in April, received your Notice of Assessment (NOA) in May, banked the refund — and now, eight months later, a Notice of Reassessment (NORA) lands in your CRA My Account inbox saying you owe an extra $2,400 plus interest because the matching program found a T5 slip you forgot to report.

This article walks through exactly what to do: how a NORA differs from your original NOA, the strict objection deadline to file a Notice of Objection, the T400A form, when to pay the disputed amount under protest, and when (and how) to escalate to the Tax Court of Canada.

The difference between NOA and NORA

Your Notice of Assessment (NOA) is what CRA sends after you first file your T1. It confirms (or quietly adjusts) the income, deductions, and credits you reported. If your return passes the automated review, the NOA arrives within 2 weeks of NETFILE filing.

A Notice of Reassessment (NORA) is what CRA sends later — months or years after the NOA — when CRA decides to change the original assessment. Common triggers include:

• Matching program — CRA’s T-slip matching system (T4, T5, T3, T5008, T4A, etc.) cross-references slips reported by employers, banks, and brokerages against what you reported. A missed slip almost always triggers a NORA, often arriving in late autumn after the matching cycle completes.
• Audit findings — a desk audit, in-person audit, or processing review (PPR) of specific deductions or credits resulted in CRA disallowing items.
• Voluntary disclosure or T1-ADJ outcome — you filed an adjustment yourself, and CRA’s processing of that adjustment generated a NORA.
• GST/HST or payroll audit — for sole proprietors or corporations, an indirect-tax or payroll audit can flow through to a personal NORA.
• Information-sharing with the IRS, FINTRAC, or provincial bodies — foreign account or property holdings flagged.

The NORA shows the revised tax owing or refund, the change vs the prior assessment, and a brief explanation of which items CRA adjusted. It also starts the objection clock.

The 90-day objection clock

Under subsection 165(1) of the Income Tax Act, an individual (other than a trust) must file a Notice of Objection by the later of (a) one year after the filing-due date for that tax year and (b) 90 days after the day the notice was sent. For most individual reassessments, the one-year-after-filing-due-date limit is the later date, so the window is often longer than 90 days. In every other case, including a loss determination or an assessment of tax on RRSP or TFSA over-contributions, the limit is 90 days from the date of the notice. The count runs from the date the notice was sent (NOT the date you received it, opened it, or noticed it in My Account). Objections go on Form T400A.

The 90-day count starts on the date printed on the NORA itself. If you ignore the deadline, your right to object is extinguished — CRA’s reassessment becomes legally final, regardless of how wrong it is.

Late-filing relief exists but is narrow. Under section 166.1, you can apply for an extension of time no later than one year after the date your objection was due. CRA says you can apply through My Account or by writing to the Chief of Appeals at the Appeals Intake Centre, and you enclose your objection with the application. You must show that:

1. You had a bona fide intention to object within the objection period but were unable to do so or instructed someone else to do so on your behalf, AND
2. It would be just and equitable to grant the extension, AND
3. The application is made as soon as circumstances permit.

CRA grants these extensions sparingly. If CRA refuses your application, or does not decide it within 90 days after you applied, section 166.2 lets you apply to the Tax Court of Canada to have the extension granted.

Rule: treat your objection deadline as a hard wall. Set a calendar reminder well before it.

What to do FIRST when you receive a NORA

Don’t fire off an objection in week one. Spend the first 2-3 weeks doing groundwork:

1. Pull your records for the year in dispute. Receipts, bank statements, brokerage statements, the original T-slips, any worksheets you used. If the dispute is about a deduction you claimed, find the supporting evidence now while it’s still locatable.
2. Compare CRA’s adjustment line-by-line against your records. Sometimes the matching program is wrong — a corrected T5 was issued and you reported the corrected amount; CRA’s system pulled the original. Sometimes you genuinely missed a slip. The path forward depends on which.
3. Check the “CRA Account Activities” page in My Account — see the actual T-slip CRA matched against, including the issuer’s full reporting. This often reveals the issuer made an error.
4. Run your own numbers. Use our tax refund estimator or recompute your T1 from scratch. If you can confirm CRA’s number is correct, your decision tree shifts to “pay and move on” rather than “object.”
5. Decide: pay, object, or both. Interest accrues on the disputed amount whether you object or not (more on this below).

Filing a Notice of Objection (T400A)

Once you’ve confirmed CRA’s adjustment is wrong (or arguably wrong), file Form T400A — Notice of Objection via:

• Online: CRA My Account → “Register a formal dispute (Notice of Objection)”. Fastest; instant timestamp for the 90-day clock.
• Paper: mail Form T400A to the CRA Appeals Intake Centre listed on the form for your region.

Include in the objection:

• The NORA reference number and date.
• The tax year(s) at issue.
• A clear statement of the items in dispute (e.g., “CRA disallowed $8,400 of motor vehicle expenses claimed on Form T2125 — these expenses are properly deductible because…”).
• The relief sought (e.g., “reverse the reassessment and restore the original NOA”).
• Supporting facts and evidence — receipts, log books, contracts, prior correspondence. You don’t have to attach everything; you can submit additional documentation later, but a strong initial submission moves faster.

After CRA Appeals receives the objection, an Appeals Officer (independent from the auditor who issued the NORA) reviews. The CRA’s 2025–26 service standards aim to resolve a low-complexity objection (for example credits, income on an information slip, or deductions) within 180 calendar days and a medium-complexity objection (for example business expenses or more complex T1 issues) within 365 calendar days of receiving it, 80% of the time. Complex or grouped objections can take longer.

CRA’s guide to objections (P148) describes two outcomes. If CRA agrees with you in whole or in part, it adjusts your return and sends a notice of reassessment. If it disagrees, it sends a notice confirming the assessment was correct.

• Notice of reassessment — CRA agrees in whole or in part. You receive an updated notice with adjusted figures.
• Notice of confirmation — CRA upholds the NORA. Your next step is the Tax Court of Canada.

Interest keeps accruing while you object

Filing an objection does NOT pause arrears interest. CRA continues to charge arrears interest compounded daily on the disputed balance throughout the entire objection and appeal process.

The 2026 prescribed rate for tax owing is 7% per year (CRA prescribed rate for overdue taxes = base rate + 4 percentage points, currently 3% + 4%). On a $2,400 balance held for 12 months, that’s roughly $168 of interest stacking on top.

The hedging move: if you’re confident you’ll win the objection, pay the disputed amount under protest now (CRA My Account → “Make a payment” → applies to the reassessed balance). This stops arrears interest immediately. If you eventually win, CRA refunds the amount plus refund interest at the prescribed rate for overpayments (currently 5% annually for individuals, compounded daily) — so you come out roughly whole. If you lose, you avoided the interest hit; the only “cost” is the opportunity cost of the funds for the duration of the dispute.

If you genuinely cannot pay the disputed balance, file the objection and accept that interest will accumulate. CRA does not pursue collection on disputed balances while the objection is active (per CRA’s collections policy), but the interest debt grows.

Worked example

Facts: You’re a self-employed graphic designer in Alberta. You filed your 2024 T1 in April 2025 claiming $8,400 of home-office and equipment expenses on Form T2125. NOA arrived April 28, 2025 confirming a $1,200 refund.

In June 2026 (14 months later), CRA Processing Review requests support for the expenses. You send receipts in July 2026. In August 2026, CRA issues a NORA disallowing $8,000 of the $8,400 on the grounds that the home office was used “only partially for business” and the percentage allocation was inadequately documented. The NORA shows additional tax owing of $2,400 plus interest already calculated at $180 (accrued from May 1, 2025 to August 2026).

Your options:

1. Pay $2,580 now, no objection. Total cost: $2,580. Move on.
2. Object without paying. File T400A in September 2026 with a properly documented home-office percentage calculation, square-footage measurements, and a log of business use vs personal use. Assume Appeals takes about 10 months (illustrative; the CRA’s standard is 180 days for low-complexity and 365 days for medium-complexity objections). Interest accumulates ~$140 over that period on the $2,400 balance (7% × 10/12).
   • Win: $0 tax + $180 interest already paid is refunded with refund interest (~$8) → net cost ~$0.
   • Lose: owe $2,400 + $180 + $140 = $2,720. Worse than paying upfront.
3. Pay $2,580 under protest AND object. Interest stops immediately. Assume Appeals takes 10 months.
   • Win: refund $2,400 + refund interest on the period CRA held it (~$100 at 5%) → net cost ~$80 (the original $180 interest hit, partly recovered).
   • Lose: no further cost; you already paid. Net cost: $2,580.

Decision rule: if you assess your win probability above ~50%, pay under protest AND object. The downside is bounded; the upside is the refund plus interest.

Tax Court of Canada — when CRA Appeals says no

If CRA Appeals confirms the NORA, you have 90 days from the date of the Notice of Confirmation to file an appeal at the Tax Court of Canada (TCC) under section 169 of the ITA. The TCC is a federal court that hears tax disputes only.

The TCC has two procedures:

• Informal procedure — for income tax, cases where the federal tax and penalties in dispute for each taxation year, excluding interest, are $25,000 or less, or where the loss in question is $50,000 or less (for GST appeals, the amount at issue must be $50,000 or less). You may also agree in your Notice of Appeal to limit a larger appeal to those amounts. Simplified rules, and the Tax Court says there are no filing fees.
• General procedure — anything larger, or any case you’d rather litigate formally. More formal rules and legal steps. The filing fee is $250, $400 or $550 depending on the amount in issue.

The informal procedure is well-suited to most personal disputes (denied deductions, missed slips, principal residence exemption disputes, disability tax credit denials). The general procedure is for complex corporate, international, or large-dollar matters.

Above the TCC, appeals run to the Federal Court of Appeal and ultimately the Supreme Court of Canada, but these are vanishingly rare for personal tax disputes.

Statute-barred years — when CRA can no longer reassess

The CRA’s reassessment window is governed by subsection 152(4):

• 3 years from the original NOA date for individuals and CCPCs (private corporations).
• 4 years for other corporations and mutual fund trusts.
• No time limit under this subsection if the taxpayer made a misrepresentation attributable to neglect, carelessness or wilful default, or committed fraud, in filing the return or supplying information.
• The period set out in the waiver if you filed a waiver (Form T2029) within the normal reassessment period.
• 3 more years after the normal reassessment period for an assessment made as a consequence of a transaction involving a non-resident person you were not dealing with at arm’s length (the section 247 definition of “transaction” applies).

So if a NORA arrives on a return from several years ago and CRA is not alleging misrepresentation/fraud, you didn’t sign a T2029, and no other 152(4) exception applies, the reassessment may itself be statute-barred — that becomes the core of your objection. Subsection 152(4) allows a reassessment outside the normal reassessment period only if one of its conditions is met.

This is also why never sign a Form T2029 waiver without legal advice. CRA frequently asks taxpayers to sign waivers when a year is approaching the 3-year deadline; signing extends the window indefinitely and gives away a powerful statute-of-limitations defence.

Decision framework

When a NORA arrives:

1. Day 0-7: read it carefully, pull records, compare to your filing.
2. Day 7-30: confirm CRA is right or wrong. If right, pay and move on. If wrong, continue.
3. Day 30-60: draft Notice of Objection (T400A) with evidence. Decide whether to pay under protest.
4. Day 60-90: file objection via My Account (and confirm your actual deadline: the later of 90 days or one year after the filing-due date for most individuals).
5. Wait for the Appeals decision (the CRA’s standard is 180 days for a low-complexity objection and 365 days for a medium-complexity one).
6. If unfavourable: 90-day window to file at TCC informal procedure (under $25k) or consult counsel for general procedure.

Run the impact of the disputed amount through our tax refund estimator to see exactly what’s at stake on your final balance owing or refund.

Related reading

• CRA Notice of Assessment explained — the original NOA that the NORA modifies.
• Missed the April 30 tax deadline — what to do — late-filing penalties that compound the NORA hit.
• T1 adjustment — how to fix your Canadian tax return — the proactive flipside, before CRA reassesses you.

FAQ

Q: I disagree with the NORA but I missed the 90-day deadline. What can I do?

A: First check your actual deadline. For an individual it is the later of one year after the filing-due date and 90 days after the notice was sent, so you may still be in time. If you are late, apply for an extension under section 166.1 as soon as possible, and no later than one year after the date your objection was due, through My Account or by writing to the Chief of Appeals. Enclose your objection. You must show that, within the objection period, you could not object or have someone else object for you, or you intended to object, and that it would be fair to grant the application. CRA grants these requests sparingly. If CRA refuses the application, or does not decide it within 90 days, you can apply to the Tax Court of Canada under section 166.2.

Q: Can CRA reassess my 2020 return in 2026?

A: For an individual taxpayer, the normal 3-year reassessment window from the 2020 NOA (issued ~May 2021) closed in May 2024. CRA can reassess after that only if a subsection 152(4) condition is met, such as misrepresentation due to neglect, carelessness, wilful default, or fraud, or a Form T2029 waiver you filed within the normal period. If a 2026 NORA on a 2020 return arrives, check the statute-barred argument first — it may be invalid on its face, and that’s the core of the objection.

Q: Does objecting to a NORA flag me for audit on future returns?

A: No. CRA Appeals is a separate division from Audit; objection records are not shared back to Audit’s risk-scoring system for routine future return selection. Filing an objection is a normal and frequent taxpayer action — CRA processes hundreds of thousands per year. The exception is if your objection reveals systemic issues (e.g., undeclared income across multiple years) — in which case CRA may extend the review. For a routine missed-slip or disallowed-deduction dispute, objecting is the right move with no flagging consequence.