I have someone that hasn't done anything for 10 years can I file that far back

[TurboTaxSusan]

Yes, you can still prepare returns for the last 10 years. However, we only have TurboTax products available for 2015 to 2020. You can see what we have for previous years here: https://turbotax.intuit.ca/tax-software/prior-year-taxes.jsp

The CRA has tax return packages available for download from 1985 onward here: https://www.canada.ca/en/revenue-agency/services/forms-publications/tax-packages-years.html

Also, you will have to print & mail any returns from before 2017, as the CRA no longer accepts any previous years via NETFILE. You can get an address to mail to on this CRA webpage: https://www.canada.ca/en/revenue-agency/corporate/contact-information/where-mail-your-paper-t1-retur...