How to change your tax return after filing

Your taxes are over for another year or so you thought: you carefully filled out the forms and submitted them on time. Suddenly, you realize you've made a mistake! Were your efforts for nothing? Here's what to do if you need to change your tax return after filing it.

How to change your tax return after filing

Wait for a reply from the government

Don't send in a second return for the same year! Whether you file online or mail a physical copy, submitting a second income tax return will only create confusion. Before you request any kind of update to your income tax return wait to receive your notice of assessment, which will be issued to you by the Canada Revenue Agency (CRA). Thereafter you’ll be able to submit a change request to the CRA.

Placing a change request

When you're ready to place a change request, you can do it online or by mail.

  • According to the CRA, you can request changes to your tax returns going back 10 previous calendar years. Just know that when you request a change to your tax return , the government will consider it, meaning it's not guaranteed they will.

To make a change request online

To make a change request online, you’ll need to log on to "My Account for Individuals" with the Canada Revenue Agency and select “Change a return.”

To make a change request by mail

To make a change request by mail, you’ll need to complete a T1-ADJ-T1 Adjustment Request form and remit it to your nearest tax centre with any supporting documents that have not already been submitted.

  • Essentially, you’ll indicate on the form which line or lines were erroneous on the first return you submitted and the revenue office will adjust the total in consequence.

Your change request reassessment

After filing, you’ll receive a notice of reassessment indicating the changes made to your return and the impact it has on the final amount.

  • You'll also receive a letter detailing what changes were, or were not, made along with an explanation if the changes you requested were deemed unnecessary.

How long will it take for the changes to be made?

  • If you filed online, your change request will take about two weeks to be processed.
  • If you filed by mail, your change request will take approximately eight weeks.

Change request steps and checklist

  • Make sure you’ve received your notice of assessment.
  • Have your supporting documents ready (only if they were omitted in the original tax return).
  • Make your change request online or by mail (do not send any other documents or another tax return).

It's that simple

Although filing taxes can be stressful, you need not stress about mistakes made in earnest. They happen under the pressure of trying to get everything together and correctly submitted on time and should be, for the most part, correctable if your intention wasn't to deceive. Should you find it necessary to file a change request with the CRA and are worried, seek the help of an accountant or tax preparation professional.

The material on this website is provided for entertainment, informational and educational purposes only and should never act as a substitute to the advice of an applicable professional. Use of this website is subject to our terms of use and privacy policy.
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