@MartyDC - the IRS is controlling the limit - not Turbo Tax. This is the way the IRS limits the risk of fraud.... since turbo tax (and other competitive softwares) are supposed to be used for home use and not professionally, the IRS assumes that if there are more than 5 e-files there is a higher risk of fraud as well as a better chance it is being used professionally.
The desktop version of turbto tax can produce an unlimited number of tax returns. While 5 can be efiled, the rest have to be paper filed.
here is the link to taxact, a competitor, stating the same thing
https://www.taxact.com/support/313/2019/e-filing-limit-of-five-returns#:~:text=If%20you're%20not%20a....
