To change your User ID or Password, you'll want to be logged into your TurboTax online account.
- Go to your Intuit Account and sign in to your account.
- Click on Intuit Account in the lower left corner of the screen. This will open your Account Settings screen.
- Click either Profile or Security depending on which options you want to update.
- To change your User ID go into Profile tab and click on the Edit option to the right of your User ID and follow the onscreen instructions.
- To change your Password, click on the Security tab and then click on the Edit option to the right of your Password.
- Enter the new information.
- Enter your existing password, if asked (it depends on which option you are updating).
- Click Save.
From here, you can also update other account information, add a phone number for increased security, or turn on two-step authentication.
From TurboTax FAQ:
https://ttlc.intuit.com/questions/2578433-how-do-i-change-my-turbotax-login-user-id-or-password
