TurboTax Online, you can do just that with the Clear & Start Over feature as long as you haven't paid or registered yet.
- Sign in to TurboTax Online and open your return by clicking the orange Take me to my return button.
- From the My Account dropdown menu, select Clear & Start Over.
- Answer Yes to Are you sure you want to clear your return?
- After your entries have been cleared out, we'll prompt you to select a TurboTax product so you can start over from the very beginning.
- If you're signed in under last year's login, we'll automatically transfer last year's info over if you select the PLUS upgrade, Deluxe, Premier, or Self-Employed. Federal Free Edition (without PLUS) does not include the year-over-year transfer feature.
If you can't Clear & Start Over after you've registered, and it's convenient, consider opening a new account under a new username. Up to 5 accounts can be tied to the same email address.
Otherwise, try to post another question about your problem and someone should be able to help you fix it.