Archiving a student removes their access to Mindjoy and frees up the seat. Their work is kept.
From a classroom
Open the classroom, go to the Students tab, click the three dots on their row and choose Archive account.
From the organisation
Click your organisation name at the bottom of the sidebar and choose Organization, then open the Students tab. You need to be an organisation admin.
Click the three dots on their row and choose Archive.
To reverse it, see Unarchive a Student.