What is the ruling on working as an employee or a teacher in private universities and colleges that pay their employees' salaries from late fees imposed on students for not paying tuition fees on time?

It is not permissible to impose a fine on students for late payment of tuition fees, and therefore, it is not permissible to work in imposing this fine or assisting in it. As for working in teaching or other administrative tasks that are not related to the fine, it is permissible. The inclusion of the fine in the university's budget does not affect the salary received for permissible work, due to the permissibility of dealing with mixed funds.