All males under 18 years are held in the separate Young Offenders Centre.
Females under 18 years have been held with females over 18 years, initially in Mourne House at Maghaberry and then since 20 June 2004 at Ash House in Hydebank Wood prison. Precise figures prior to June 2004 could be obtained only at disproportionate cost. The number of females committed to Hydebank Wood prison is as follows:
| || Number |
|2008 (to 11 July) ||2 |
|2007 ||3 |
|2006 ||8 |
|2005 ||10 |
|2004 ||6 |
Following an amendment to the Criminal Justice (Children) NI Order 1998, since 7 June 2008 all females aged 17 or under are detained at Woodlands Juvenile Justice Centre.