If you want to
prepare another return using TurboTax Online, you will need to set up another
account. TurboTax Online is set up to be one tax return per account,
however you can have up to 5 accounts per email address.
See the TurboTax FAQ
below for instructions on how to set up another account to prepare another
return.
https://ttlc.intuit.com/replies/3288574