It is better to start a new TurboTax account to do your taxes, rather than using your dad’s account.
As Champ @xmasbaby0 says, you can only prepare and file one person per TurboTax online account. The CD/desktop version allows you to e-file up to five tax returns and more if you mail the others in.
If you wish, you can delete all your dad’s information and put in your own, but all the previous tax history in the account will be your dad’s so we don't recommend doing that.
You can link more than one TurboTax online account to the same email, but each account would need a separate user ID.
If you do another return in the same account it will overwrite the first one and it will be gone for good.
Online is only good for 1 return per account. But you can use the same email address for 5 accounts. How to start another return in the Online version
The Desktop CD/Download program can do unlimited returns.
Thats why if you need to do more than 1 return we recommend you buy the Desktop CD/Download program. It can do unlimited returns and efile 5 for free. And you can buy a lower version. All the Desktop programs have the same forms. You just get more help and guidance in the higher versions. Buy the Desktop program in stores or directly from Turbo Tax here