We're building out some functionality revolving around portal/community users which will partially rely on them being associated with a contact (we have a custom object that looks up to contact). The problem I'm facing is that if we want someone who is an existing user to be able to use the same functionalities, they won't have a contact associated with them if they are a full license user. Making them pay for/create a second user seems like it would not be the best option. Is there a way we can add a contact to an existing User in their system?
Note: I am NOT asking to switch which contact is associated with a portal/community user. This is a user that has no Contact associated with it.