You have to wait until your return has been processed before you can make any changes. You can only make changes to returns going back 10 years.
Federal income tax returns
Once you've filed your income tax return, you have to wait until you’ve received your notice of assessment from the Canada Revenue Agency (CRA) if you need to make any changes.
There are three ways that you can make changes to your federal tax return, after you have received your notice of assessment:
- Login to My Account on the CRA website, and use the change my return option
- Complete form T1 : Adjustment Request form (T1-ADJ) and send it to your local tax centre
- Write a letter to your local tax centre, containing all of your personal information and the details you need to change (tax year, amount, reason)
Note: If this is your first year filing a tax return, you won’t be able to use the services typically available through the Canada Revenue Agency (CRA) My Account; this is because the CRA requires that you file one tax return before you can register for the My Account service.
Québec income tax returns
There are two ways that you can make changes to your Quebec tax return:
- Complete form TP-1.R-V : Request for an Adjustment to an Income Tax Return and mail it, along with the details you need to change (tax year, amount, reason) to Revenu Québec
- Use the Request to Change Income Tax Return Information service online
Where can I learn more?
- How to change your return (CRA website)
- Tax centres (CRA website)
- T1 Adjustment Request (T1-ADJ) (CRA website)
- Changing an income tax return that you have already filed (Revenu Québec website)
- Request to change income tax return information (Revenu Québec website)
- Request for an adjustment to an income tax return (TP-1.R-V) (Revenu Québec website)