Looks like your are posting from the Online Premier version. 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
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-onli...
Or go to the IRS Free File programs
Free File: Do your Federal Taxes for Free | Internal Revenue Service
The Desktop CD/Download program can do unlimited returns.You can move your Online file to the Desktop program and continue without paying for Online or needing to reenter your info. If you already paid for the Online version you can ask them for the Desktop program. And you can buy a lower version Desktop program. All the Desktop programs have the same forms. You just get more help and guidance in the higher versions.
You can buy the CD/Download here,
https://turbotax.intuit.com/personal-taxes/cd-download
