For TurboTax Online 2017, you can use the Return Manager (under Tools) to start a new return. Later,
you can go back to the Return Manager and click on the small blue trash can
next to the return you no longer want to delete it.
For TurboTax Online 2018, you can select Start A New Return under My Account & Returns in the left
side menu. Later, you can select View
All Tax Returns under My Account
& Returns and click on the trash can next to the return you no longer
want to delete it.
