We established our own rule, which is 12 months of inactivity (not even a log in). The users are receiving warnings (1 month/week/day before).

I don’t delete inactive users, so long as they are still a customer/partner/employee. But if people leave their organization, this is what I do:

When an employee leaves the company:

• if they have no content, I delete the account.
• if they have content, I change them from a employee role to former employee, which removes any access they have to content. Both are custom roles.

If a customer leaves their company (and therefore community access), I do the same - delete them if they don’t have content OR move them to “former customer” with no access.

I haven’t removed users just for being inactive, but I’d be keen to hear if that’s a best practice. As long as they are a customer/partner, I don’t want to make them rejoin, should they want to use the community at any point.