Filing Your Return

Changing your tax return once you have already filed it.

If you have filed your return and then determine that you need to make a change, either because you have received another T-slip, or because you didn't claim an expense and later learned it was deductible, you can request an adjustment to your tax return.

You can request the change

Requesting a change online

Requesting a change online is very simple, and is done by logging into your account at the CRA My Account page.  A separate request has to be filed for each tax year.

You can also use the online request if you forgot to apply for the GST/HST tax credit when you filed your tax return.

Requesting a change by mail

You can obtain a form T1Adj from the CRA web site, complete it and mail it in, along with documents supporting your change request.  The time limit for filing adjustments to your tax returns by mail is ten years.  An adjustment request may be made in 2008 for the 1998 or subsequent taxation years.

See also the CRA web page How to change your return.