Secondary, or senior, schools take pupils up to the end of the sixth form at 18, but there is no uniform entry age. Broadly speaking, the normal entry age for girls is 11 (Year 7), with some schools taking girls also at 13 (Year 9). Boys' normally move either at age 11 (Year 7) or 13 (Year 9), depending on the school; the traditional boys' public schools start at Year 9. In Scotland secondary schooling begins at age 12.

Many independent secondary schools have their own junior, prep and even nursery departments so can provide straight through education from 2½ (or even earlier) up to 18. This may make life easier for parents but not necessarily for their children - 15+ years in the same school may seem a very long time.
Transfer from linked junior schools is not normally guaranteed − although the pupils will undoubtedly be well prepared for the senior school's entrance procedures. Preparatory (or prep) schools traditionally prepared pupils for Common Entrance (CE) − although the term has recently been highjacked by junior schools not concerned with CE.

Parents should choose a junior school to suit their children, rather than as a feeder school to a favoured secondary school. Junior schools are often very different from their senior school: a junior school may be small, cosy and supportive while its senior school is large, boisterous and competitive. It is worth reviewing school choices at ages (say) 8, 11, 13 and especially 16, to check whether it is time to consider changing schools.