Supply teachers have always been the go-to force to stand in when teachers are either absent or unable to teach their usual classes. Being called in either on the day, or the day before, supply teachers are fully qualified members of staff who are able and willing to cover any lessons. Often, supply teachers are brought into schools when a staff member is due to be off for a substantial period of time.

Cover supervisors, on the other hand, are a relatively new position in schools. Since the government changed their agendas, schools have found it is usually a lot cheaper to employ full time Cover supervisors, rather than hiring supply teachers. Cover supervisors again, cover any lessons in school. They do not have to plan lessons, more they deliver work which has been prepared by teachers already. Cover supervisors are sometimes used as additional support, seeing as they are employed directly by schools.