When you use Online TurboTax, you get one return per fee. Each return needs its own account and user ID. If you use the same account and user ID for a second return, you overwrite the first one and lose it forever.
Each tax return requires a separate account with a separate username and password, but you can use the same email address for all of them. 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.
Please click How do I start another return in TurboTax Online? to learn more.
You can generate several returns from your TurboTax software. For many years in the past I generated returns for myself, and separate ones for my adult son and daughter. After opening TurboTax, you just click "Start a New Return" button, ten make sure that you save it under a different name then your first return.
However, each software package includes e-filing for a limited number of returns, I do not remember if it is for one or several. So you may have to pay a fee for e-filing second or third return. Printed and mailed returns are free, except for the cost of postage, no matter how many you prepare.
@gceller The reply you provided pertained to using the CD/download. The original poster in this thread was using online software, which is priced differently. With onlineTurboTax a user gets one return per fee.