Have 2020 turbotax with 8 returns. Can I use this soft for amended returns for past years ?

[TurboTaxSusan]

No you can't.

You can make changes after you have filed your tax return through the Canada Revenue Agency (CRA) or through ReFILE. This FAQ has more information: https://turbotax.community.intuit.ca/community/tax-return-amendment/help/i-have-filed-my-tax-return-...

[Cheryl89]

I need to submit 10 years of taxes for a relative how do I do that?