Sometimes, after you submit a tax return, you need to make changes. The Canada Revenue Agency (CRA) lets you make changes to tax returns submitted in any of the previous 10 calendar years. You can make changes to tax returns you have already filed online or by mail. Changes to your tax return are only allowed in certain situations, and you must include supporting documentation with your request.

How to Change Information Submitted Online

You can make changes to your tax return online through the CRA My Account service. Start by logging in to your account online with your User ID and password. Under the Quick Links, click on the link that says Change my return. Select the year you’d like to change from the drop-down menu. You can do a search of your T1 General for changes you’d like to make by entering the description or line number.

For example, you can enter “employment income” or “101” to bring up the line related to employment income. You can also browse the sections of your tax return and make changes manually.

You must follow all the steps for the changes to submit successfully. You can make a request for changes to one or more tax year in one submission. You receive a confirmation number once the CRA receives your request.

If you want to make further changes after submitting your request, wait until the request has been processed before submitting others. Processing time for changes submitted online is about two weeks.

How to Change Information Submitted by Mail

You can also make changes to your tax return by mail. Complete and submit a T1 adjustment request form. If you prefer to submit your changes to the CRA by mail, include supporting documentation, such as receipts, that supports the change you are requesting in your tax return and your original claim.

When mailing your change request to your tax centre, include the T1 adjustment form or a signed letter outlining your request. Include the tax years you are requesting the change for. Also, include your Social Insurance number, your mailing address and the best phone number to reach you during regular business hours.

You can download a copy of the T1 adjustment form online on the CRA website. The processing time for changes submitted by mail is about eight weeks. It may take the CRA longer to process your request if it is submitted in later summer or fall, or if your request needs further review or additional documentation.

When Changing Your Tax Return Is Allowed and Isn’t Allowed

You may only make changes to tax returns submitted in the last 10 calendar years. For example, in 2015, you can make changes to tax returns submitted from 2005 to 2014. There are several restrictions on changing your return, including tax years where there are nine reassessments, bankruptcy returns, a return filed in a year before bankruptcy, for carryback amounts and returns for non-residents.

Register for a CRA My Account.

Learn more about registering for a CRA My Account.

References & Resources