Supply teaching is a field that will vary in demand from area to area. It will all depend on the staffing of schools, how many schools there are, and whether those schools have met their teaching needs on a permanent basis. However, as a teacher, this is hard for you to know.

The best port of call for you will be a specialist recruitment agency for teaching staff. They will be able to point you in the right direction for jobs in your area, and will be able to tell you what demand is generally like. They will usually have links with certain schools, so if there are schools you would particularly want to work in, find recruitment agencies that operate in their areas. This will set you in good stead for your career as a supply teacher, and you will have access to many good opportunities in this way.