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Step 1: Wait for Your Notice of Assessment

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As tempting as it is to fix things right away, you need to wait until the CRA processes your return and sends you a Notice of Assessment.

This document confirms:

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• That your return was received and processed

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• Whether you’re getting a refund or owe taxes

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• Any changes CRA made to your return

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Once you have this notice, you can go ahead and request a change.

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Step 2: Gather the Correct Information

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Before you request any corrections, make sure you have the right numbers or documents in front of you. That might mean:

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• A missing T4 or T5 slip

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• An updated RRSP contribution receipt

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• Proof of medical expenses, tuition, or donations

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• Receipts for business or employment expenses

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You don’t have to send the documents in right away, but if CRA asks for proof later, you’ll want to have it ready.

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Step 3: Request a Change to Your Return

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There are a few ways to correct a mistake on your return:

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Option 1: Online Through CRA My Account

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This is the easiest and fastest way.

Log in to CRA My Account, select “Change My Return,” and follow the steps. You can correct most line items directly online.

 

Option 2: Use CRA’s Form T1-ADJ (T1 Adjustment Request)

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If you prefer a paper trail, you can fill out the T1-ADJ form and mail it to the CRA with a letter explaining the mistake and what needs to be corrected. Include any supporting documents if needed.

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Step 4: Wait for a Response

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Once you submit your correction, CRA will review it. This can take anywhere from a few days (if online) to several weeks (if by mail), depending on how busy they are and how complex the correction is.

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If CRA agrees with your correction, they’ll send you a Notice of Reassessment, which updates your tax return and shows your new balance, refund, or tax owing.

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Bonus: Fixing Multiple Years

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You can fix returns from up to 10 years ago. So if you missed something in a previous year — like a deduction or a forgotten slip — it’s not too late to correct it and possibly get more money back.

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Need Help? Our CPAs Can Fix It for You

 

If you’re not sure what to correct, or you just want a professional to take care of it:

 

We offer tax correction and amendment services with a Chartered Professional Accountant (CPA) for $150 CAD.

 

This includes:

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• Reviewing your tax return for missed deductions or errors

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• Submitting corrections securely to CRA

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• Answering any follow-up questions from CRA

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• Helping you avoid similar mistakes in the future with smart tax planning

 

We take the stress off your shoulders — and help you get it right.

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