Over 2 years ago I built, along with the help of Toolset technicians, a membership website that used a custom post type to create members. These members then had other custom post types associated with them.
Now I've come to a point where I need to add more options for these members, including the possibility of paying for their membership.
I want to know if it's possible to convert a custom post type to a user?
Its actually not possible to convert a custom post type to a user.
If you want your users to have a profile then you can allow them to fill out a profile CPT field which would have fields that you would normally assign to the user.
The benefit of this is that you can have publicly displayed profiles of your users.
What if I exported the CPT fields and imported that information back into WordPress as a CSV, but created users with that data? Then relink the "new" users with the other CPT associated with them previously?