Elmley opened in 1992 and is the largest of the three prisons on the Isle of Sheppey. Its primary function is to receive remand prisoners from the courts, its secondary purpose is a training establishment for a large population of sentenced category C prisoners (almost 500 currently).
- House block 1 first night and induction, currently also operating as reverse cohort unit
- House block 2 remand and convicted prisoners
- House block 3 substance recovery, working in partnership with Forward Trust
- House block 4 remand and convicted prisoners
- House block 5 enhanced and category C prisoners and full-time workers
- House block 6 foreign nationals and sex offenders