Traditionally, preparatory (or prep) schools are junior schools that prepare pupils for Common Entrance (CE) at 11 or 13. The term has recently been adopted by all sorts of junior schools not concerned with CE.

Prep schools take pupils from the age of 7 or 8 and may have pre-prep departments, taking pupils from age 4 (maybe also a nursery from age 3 or even earlier). Pupils from some prep schools go on to secondary schools all over the country. Others have links with, or are prep departments of, specific secondary schools. Good prep school Heads will know the ropes and be experienced at matching their pupils to the secondary schools they feed. Many Heads and deputy heads belong to the professional organisation, IAPS (Incorporated Association of Preparatory Schools).