When you delete a student, they are not deleted from the system, they are only made inactive in your account. This allows us to be able to restore students to an account if they have been accidentally deleted or you need access to their original data.
Student ID numbers are designed to be unique to an individual student. If an account holder already has an ID assigned to them, it is the ID# their data is tied to. If you try to re-use a student ID number, it is quite likely that the system will pull up the prior students’ data — which is not what you would want. You will need to select a new ID number for the new student.