sharing turbo tax with my immediate family

[SLYKTAX]

Best answer you provided!

Now I believe it is like this. Hopefully it is accurate.

There is a distinction between a desktop version and an online version.

Working online required login -  obviously needed. The login user is limited to the one who registered as the software owner.

Working on a desktop version shouldn't required anyone to login and work to finish because the software is activated.  However, when coming to efile the return, the person has to login and provide his own account so that he could provide his credit card # to be charged for efiling, especially the State return.

[SLYKTAX]

Ya.  I have been using a flash drive with only the very last past year tax file to be transferred and start working for years without failing. 

At the end of efiling for the year,  I just have to save two extra copy to two portable drive where all my past tax files are kept just incase one died. 

Now the flash drive I work on have would have this year and last year tax return files.  I would delete last year and kept this year in the drive to be transferred next year.

It works fine.  Even it get corrupted, I still have the backup.  I let my family  members use my laptop and they use their own flash drive to work on theirs.

[VolvoGirl]

You now need to create or log into an Intuit Account to use the Desktop program.

Since you now have to log into an Intuit Account when you first install it, all your downloads and licenses are listed there (even if you bought it from somewhere else) so if you need to install it again or install on another computer, even on the other operating system (Windows, Mac) you can download it again.

See this FAQ on How to get started with Desktop. Scroll down to - You need an Intuit Account to use TurboTax Desktop for a few reasons:
https://ttlc.intuit.com/turbotax-support/en-us/help-article/license-information/install-turbotax-cd-...