Some teachers choose to work as a supply teacher either because it fits in better with their family life especially if they have young children or are caring for an elderly relative, or because they have just moved into a new area and are unfamiliar with the schools in the new area.
The advantages of the flexible working patterns that come hand in hand with supply teaching suit many teachers. Should you have children of your own at school you will be free to attend their school events without having to negotiate time off work a difficult situation that many teachers face.
Some schools will employ supply teachers to cover planned absence of teaching staff. In this case you may know in advance the year group you will be teaching and the subjects you will be required to teach. This is usually easier than having an early morning call to cover absence due to teacher illness. If unplanned cover is not suitable for you this can be made clear when you visit schools to promote yourself.
One of the main advantages of working as a supply teacher is that the administrative tasks involved in contract teaching is not expected of a supply teacher. Setting and marking of work is required and possibly some short-term assessments but report writing and data collection is not usually part of a supply teachers remit.