Licence code associated with another account

[JummyX]

I have always shared a licence code with my dad, we do not live in the same house and we always use way fewer than the 8 returns that come with the standard version.  This year, for the first time, when I went to active my TurboTax with the license code I am getting error message 608 "This license code is already linked to another account". 

I thought you could use one licence code on multiple computers.  Do I have to log in with my dad's account?  Will that affect me when I go to submit my return to the CRA if I am logged in with his account?

Thanks.