T1 Adjustment Request: ReFILE, Change My Return, and Form T1-ADJ

A T1 Adjustment Request is how you correct a Canadian personal income tax return that the Canada Revenue Agency has already assessed. You can use it to add missed income, claim deductions or credits you forgot, or fix a mistake on any T1 return filed in the previous 10 calendar years. Most requests can be submitted online and are processed in about two weeks.¹

When You Can File One

Wait for your Notice of Assessment before requesting any change. The NOA is the CRA’s summary of how it processed your original return, and submitting an adjustment before it arrives can cause delays or an outright rejection.¹²

Once the return is assessed, you have 10 calendar years to ask for a change. No refund can be issued for a request made more than 10 calendar years after the end of the tax year in question.¹³⁴

Sooner is better. Records are easier to find, and the CRA is less likely to have questions about the delay.

Three Ways to Submit

ReFILE Through Tax Software

ReFILE is usually the fastest option. It works through certified tax software and sends your corrections directly to the CRA using the existing EFILE or NETFILE channels. You don’t have to use the same software you originally filed with, though it’s often easier because your data is already loaded.¹

ReFILE currently covers the 2022 through 2025 tax years.⁵ You can’t use it while an assessment or reassessment is already in progress, or to change identifying details on page 1 of your return. The service also goes down briefly each February while the CRA updates it for the new tax year.¹

Change My Return in CRA My Account

If you have a CRA My Account, the “Change my return” tool guides you through the adjustment for any of the 10 previous calendar years, a much wider reach than ReFILE.⁶ Select the tax year, enter the revised line amounts, and submit. The portal confirms receipt immediately. You don’t send supporting documents unless the CRA specifically asks.

Paper Form T1-ADJ

For returns outside the ReFILE years, or if you prefer paper, complete Form T1-ADJ and mail it with all supporting documents to the tax centre that serves your area.⁷ Mailing addresses for each province and territory are on the CRA website. Send everything together so the file can be processed in one pass.

What to Put Together Before You Submit

You need three things: the exact line numbers you want to change, the original and revised amounts for each line, and documents proving the new figures.

Every entry on your T1 has a line number. Employment income from a late T4 goes on Line 10100.⁸ Missed medical expenses go on Line 33099.⁹ For each line you change, record both the amount you originally reported and the corrected amount.

Supporting documents depend on the change: a T4 slip received after filing, a charitable donation receipt you overlooked, a child care expense receipt, a tuition certificate. If a related schedule is affected, update it too. Adding tuition credits, for example, means updating Schedule 11.¹⁰

If you’re filing on paper, the T1-ADJ has a section for explaining why each change is needed.¹ Keep it factual and short. Something like “Employer issued corrected T4 on March 15 showing additional $2,400 in employment income” reads better than a paragraph of context. Include your Social Insurance Number, full name, and a daytime phone number. A clean, complete request is much less likely to trigger a broader review.

Changes That Don’t Use a T1 Adjustment

Some corrections use a different process, and filing the T1-ADJ for them just wastes time.

Loss carrybacks. To apply a non-capital loss from the current year to a prior year, use Form T1A, Request for Loss Carryback. Non-capital losses can be carried back three years. The CRA explicitly says not to file an amended return for the year you’re applying the loss to.¹¹
Changing a tax election. Modifying or revoking a previous election runs through a separate application process that involves a penalty payment. A T1-ADJ can’t do it.¹²
Personal information. Name, address, marital status, date of birth, and direct deposit updates aren’t handled through ReFILE or the T1-ADJ. Use My Account or call the CRA.⁵

Processing Times and Tracking

Online submissions through ReFILE or Change my return take about two weeks. Paper T1-ADJ requests take roughly eight weeks. Both timelines can stretch during peak periods around tax season.¹

You can follow the request through the Progress tracker on the Overview page of CRA My Account. A status of “Adjustment request in progress” means the CRA has it and is reviewing. The tracker shows a target completion date matching the CRA’s published service standards, the same date a phone agent would give you. Files stay visible in the tracker for 30 days after completion.¹³

One caution: if you’ve already sent an adjustment for a given return, wait for the CRA’s response before requesting further changes to that same year. Overlapping requests create confusion and slow both down.¹

What You Get Back

When the review is finished, the CRA issues a Notice of Reassessment. The NOR replaces the earlier NOA and becomes the official record for that tax year, showing the updated amounts and any refund or balance due.²

If the adjustment produces a refund, the CRA pays interest at the prescribed rate. For the first quarter of 2026, that rate is 5% annually on non-corporate overpayments.¹⁴ If the adjustment shows more tax owing, interest runs from the original due date of the return at 7% annually.¹⁵ These rates are updated quarterly.

Penalties for Unreported Income

Filing an adjustment doesn’t itself trigger a penalty. Leaving income off the original return can. If you fail to report $500 or more of income in a tax year and also failed to report income in any of the three preceding years, the CRA can apply a repeated failure to report income penalty. The penalty is the lesser of 10% of the unreported amount, or 50% of the difference between the understated tax (or overstated credits) and any tax already withheld on that amount.¹⁶

Correcting the return before the CRA finds the omission is almost always the better outcome. For more serious omissions spanning multiple years, the Voluntary Disclosures Program may reduce or eliminate penalties and some interest. To qualify, all five conditions have to be met: the disclosure must come before the CRA starts an audit or investigation, it must include complete information for all affected years, it must involve tax genuinely owing (not a refund claim), the information must be at least one year past due, and it must include payment or a proposed payment arrangement. The VDP is not available for refund situations, insolvency cases, or where penalties and interest have already been assessed. The CRA offers an anonymous pre-disclosure discussion if you want to gauge eligibility before applying.¹⁷

If the CRA Denies Your Adjustment

A denied adjustment or a Notice of Reassessment you disagree with doesn’t end the matter. The CRA suggests starting informally, by calling or writing to discuss the issue, since many disputes get resolved without escalation.¹⁸

If that doesn’t work, you can file a formal Notice of Objection on Form T400A. An adjustment request says “I made a mistake on my return.” An objection says “the CRA misinterpreted the facts or applied the law incorrectly.”¹⁸

For individuals, the deadline to object is the later of one year after the filing due date for the return, or 90 days from the date on the notice of assessment or reassessment. If you miss that window because of circumstances beyond your control, you can apply for a time extension up to one year after the original objection deadline. While an objection is active, the CRA normally postpones collection on the disputed amounts until 90 days after it sends its decision.¹⁸

1
Canada Revenue Agency. Changing a Tax Return
2
Canada Revenue Agency. Notices of Assessment – NOA or NOR – Personal Income Tax
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Canada Revenue Agency. Extend the Deadline for a Tax Refund or Reassessment
4
Justice Laws. Income Tax Act RSC 1985 c 1 (5th Supp) – Section 152
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Canada Revenue Agency. ReFILE Terms and Conditions and Privacy Notice
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Canada Revenue Agency. Do You Need to Change Your Tax Return? Skip the Paper Request – Do It Online!
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Canada Revenue Agency. T1-ADJ T1 Adjustment Request
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Canada Revenue Agency. Line 10100 – Employment Income
9
Canada Revenue Agency. Lines 33099 and 33199 – Eligible Medical Expenses You Can Claim on Your Tax Return
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Canada Revenue Agency. Schedule 11 – Federal Tuition, Education, and Textbook Amounts and Canada Training Credit
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Canada Revenue Agency. Line 25200 – Non-Capital Losses of Other Years
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Canada Revenue Agency. Amend, Revoke, or File a Late Tax Election
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Canada Revenue Agency. Progress Tracker
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Canada Revenue Agency. Prescribed Interest Rates – 2026 – Q1
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Canada Revenue Agency. Prescribed Interest Rates – 2026 – Q2
16
Canada Revenue Agency. False Reporting or Repeated Failure to Report Income
17
Canada Revenue Agency. Voluntary Disclosures Program (VDP) – Who Is Eligible
18
Canada Revenue Agency. Resolving Your Dispute: Objection Rights Under the Income Tax Act