To make changes to your federal return before mailing you can access the federal part of your return is you "add a state" from your timeline. You aren't really adding one, it's just to access your federal return.
- Sign into your TurboTax account online version.
- On the Overview page, click on My TurboTax > My Tax Timeline. (see image attached)
- Click on Personal Info tab
- Edit your personal information
- If you have not completed your state return,
click on the State Taxes tab.