You will get an Error Code 31 if this is your first time filing and you will have to print & mail your return. Once your first return is assessed and the Canada Revenue Agency (CRA) starts a file for you, you will be able to register for a MyAccount.
If you are using TurboTax Online, select File at the bottom of the left side menu. Then click on CRA Online Mail to go to a page where you can download a special version of your return to print off and mail.
This Canada Revenue Agency (CRA) webpage has a list of where you can mail your return: Where to mail your paper T1 return.
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