Unfortunately, once you have upgraded or added
features to TurboTax Free Online, there is no way to downgrade or remove them.
You would need to create a new return to go back to the Free product.
To create a new return in TurboTax Online
2017, click on “Tools” in the black menu in the top right, and select
“Return Manager”. You can create a new return by scrolling to the bottom of the
list and clicking "Continue" next to "Start a new 2017
return". Then once you have started your new return, you can go back into
the Return Manager and click the small Trash Can next to the unwanted return to
delete it.
To create a new return in TurboTax Online
2018, click on “My Account & Returns” at the top of the left side menu,
then select “Start A New Return”. Then once you have started your new return,
click on “My Account & Returns” again and click the small Trash Can next to
the unwanted return to delete it.
