I need to cancel a tax return that I don't know if it was sent. How can a see if it was sent and cancel it ?

Please check If you have submitted your return using NETFILE, TurboTax displays your Netfile confirmation number on your income tax return- You can see it when you log into TurboTax below or beside the return that you filed.  To check the status of your tax return, you'll need to have a CRA My Account profile. If you don't have a profile, visit the CRA website to sign up. 

Have you already submitted the return? If you have not, it is easy to delete your TurboTax Online return. Select My Returns>View All Tax Returns from the top of the left side menu. Then, click the small Trash Can next to the return you want to delete. 

And if the return is submitted to Canada Revenue Agency(CRA) then You can request a change to your tax return by amending specific line(s) of your return but can't cancel it. 

Here is a Turbotax guide on how to amend your tax return.

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