With TurboTax Online, you can create as many
returns as you would like (though you can only send 20 by NETFILE). However, you
pay per return, unless you get the Standard Online 8 return package.
You can go back and look at previous year’s
returns by logging in to the URL of that year. You don’t need to pay if have
already done so.
Tax year 2018:
https://2018.turbotaxonline.intuit.ca
Tax year 2017:
https://2017.turbotaxonline.intuit.ca
Tax year 2016:
https://2016.turbotaxonline.intuit.ca
TurboTax Online 2015 is no longer available, so
the returns from that year are no longer accessible.
If you need to create a return for 2015, you can
still use TurboTax CD/Download: https://turbotax.intuit.ca/tax-software/prior-year-taxes.jsp#2015
Here is how to get a copy of your tax return in
TurboTax Online: https://turbotax.community.intuit.ca/replies/3432773