I was able to add a user ID to my email for my daughter's return. I can't seem to figure out how to do it for my son this year. HELP!

[xmasbaby0]

When you use online TurboTax software 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, the second one overwrites the first return and it is lost forever.  

https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-onli...

@ediedillon

[VolvoGirl]

You can use the same email address for 5 accounts and returns.   You can start another return in TurboTax Online by:
Logging out if you are in your account
Choose what TurboTax Online product you want to use for the second return
https://turbotax.intuit.com/personal-taxes/compare/online

Create your account screen
Set up a new login for the second return
Start working on the new return

Or use the Desktop program. The Desktop program can do unlimited returns and efile 5 for free. And you can use any Desktop version, they all have the same forms. So you could use a lower version than you might need in the Online version.