Secure Training Centres vs Young Offender Institutions

Last reviewed: June 2026

Quick answer: Both hold children, but they are designed for different ages and needs. A secure training centre (STC) holds children aged 12 to 17 in small units with a strong education and welfare focus. A young offender institution (YOI) for under-18s holds 15 to 17-year-olds, usually in larger establishments. Alongside them sit secure children’s homes for the youngest and most vulnerable children, aged 10 to 17. Which setting a child goes to is decided by the Youth Custody Service based on age, vulnerability and risk — not by the offence alone.

When a child is given a custodial sentence, families are often shocked to learn there is more than one kind of place they might be sent. The youth secure estate is deliberately varied so that a frightened, vulnerable child is not held in the same environment as an older, more established teenager. This guide explains the differences between secure training centres and young offender institutions, and where secure children’s homes fit in.

What a secure training centre is

Secure training centres are purpose-built for children aged 12 to 17. They are smaller than YOIs and are divided into units of roughly five to eight children, which allows closer supervision and a more individual approach. Education and rehabilitation are central, with a structured timetable across the week. The smaller scale is intended to give vulnerable children more support than a large institution can provide. The youth secure estate has been changing in recent years, with the Government developing “secure schools” as a new model, so the exact mix of provision continues to evolve.

What an under-18 YOI is

Young offender institutions for under-18s hold 15 to 17-year-olds. They are generally larger than STCs and have lower staff-to-child ratios, which is one reason they tend to hold older teenagers who are assessed as less vulnerable. Education remains a core part of the regime, but the environment is closer to that of a young adult YOI than to a small, intensive unit. Separate young adult YOIs hold 18 to 20-year-olds and are part of the adult-facing estate.

Setting	Ages	Size / character	Run by
Secure training centre	12–17	Small units of 5–8; education-focused	Private contractors, overseen by YCS
Under-18 YOI	15–17	Larger; lower staff ratios	Youth Custody Service
Secure children’s home	10–17	Smallest; most welfare-focused	Local councils

How the placement decision is made

The Youth Custody Service decides where a child is held using a placement assessment. It weighs the child’s age, physical and emotional maturity, any vulnerability or history of being looked after, the risk they pose and the risk to them. The youngest and most vulnerable children are usually placed in secure children’s homes; older, more resilient teenagers may go to a YOI; STCs sit between the two. The aim throughout is to hold a child in the safest suitable setting, as close to home as the estate allows.

Secure children’s homes

Run by local authorities, secure children’s homes are the smallest and most welfare-oriented part of the estate. They hold children aged 10 to 17 — both those sentenced or remanded by the courts and, in some cases, children placed for their own safety under welfare law. Because of their size and staffing, they offer the most intensive care, which is why they are reserved for those who need it most.

Common misunderstandings

“A child chooses, or the offence decides, the setting.” Neither. The Youth Custody Service places a child according to age, vulnerability and risk.
“STCs and YOIs are the same thing.” They differ in size, staffing and ethos — STCs are smaller and more intensive.
“Under-18s can be sent to an adult prison.” They cannot. Under-18s are always held in the youth secure estate.

Frequently asked questions

Can a child be moved between settings?

Yes. If a child’s needs or risk change, the Youth Custody Service can move them to a more suitable setting.

Do children in these settings still get education?

Yes. Education is a legal expectation across the youth secure estate, and it is especially central in STCs and secure children’s homes.

How can families visit?

Each establishment sets its own visiting arrangements, but family contact is treated as important throughout the youth estate. Our guide on how to visit a prisoner explains the general process.

What happens when the child turns 18?

Transition to the adult or young adult estate is planned in advance, usually beginning at around 17 years and six months, rather than happening automatically on a birthday.

Official sources: Children in custody (GOV.UK), National Audit Office report on children in custody, Prison Reform Trust.