This is most likely a browser issue.
Log out of TurboTax and Delete any Intuit-related cookies and empty the browser's Internet cache. Then close the browser, and reopen it. Try again, but on the sign-in page, be sure there is no check mark for "remember me" until you get this resolved.
If still no luck, then do the above steps again, and if your browser has private browsing/incognito mode, try using a private window to access the TT site.
If still having problems, you can try a different browser if you have one available.
If you need to update your account information—such as phone number, email, password, or address:
- Log in to your account.
- Click Intuit Account at the top of the screen, and select Account Settings.
- Select either Profile or Security depending on which options you want to update.
- Click Edit next to the option(s) you want to change.
From here you can also turn on two-step authentication.
