In TurboTax Online, you can prepare and e-file one federal and up to five associated state returns using the same email address but a different login for each account.
Never start another return by going back and overwriting everything in the return you just filed. This will replace your info, which means you won't be able to retrieve your return later.
Follow this procedure to create another TurboTax Online account/login:
After you've created the new account/login, you can start working on the second return.
If you are planning to prepare more than one return, you may want to consider purchasing a TurboTax CD/Download as you get 5 free federal e-files with it. You can transfer your information from TurboTax Online to TurboTax CD/Download by following the instructions listed in the following TurboTax FAQ:
https://ttlc.intuit.com/replies/3302260
If you decide purchase TurboTax CD/Download you can do so by visiting the following link: TurboTax CD/Download Products