Cat B, Cat C, Cat D: the road to open prison

The category decides what the sentence feels like: how far away they are, what visits are like, and when days at home become possible. Here is how the ladder works and how people move down it.

The categories in plain words

Category	What it means	What it means for you
Cat A	Maximum security, the most serious cases	Strict visits, often far away
Cat B	High security, including most local prisons where people start	Busy, transient, hard to settle
Cat C	The standard training prison. Most people, most of the time	Steadier routine, work and courses, normal visits
Cat D	Open conditions. No walls, trust-based	Relaxed visits, day release and home leave become real

Women's prisons use closed and open instead, and the same logic applies.

How people move down the ladder

Reviews: the first within about a year, then roughly yearly. Big changes can trigger an early one.
What the review weighs: offence and sentence length, behaviour and adjudications, courses completed, escape risk, and time left to serve.
The usual journey: start in a Cat B local, move to Cat C for the middle of the sentence, then Cat D in the later stage. Open conditions in the last stretch is common for standard sentences, and is where ROTL starts working for families.
Lifers and IPP: the move to open conditions usually comes through Parole Board recommendations instead, as a step towards release. See the parole timeline.

What actually speeds it up

A clean record: nickings set reviews back more than anything else.
Doing the sentence plan: the courses named in it are the boxes the review wants ticked. If a course has no places, asking the OMU to record that in writing protects the next review.
Working and engaging: purposeful activity reads as reduced risk.
From family: a stable address and visible support helps the resettlement picture, and matters more the closer open conditions get.
The full official rules are in the security categorisation policy framework on GOV.UK.

Common questions

What do the prison categories mean?

For men: Cat A is maximum security, Cat B high security, Cat C is the standard training and resettlement prison where most people are, and Cat D is open conditions with no walls and day release possible. Women’s prisons use closed and open instead. Everyone is categorised soon after sentencing and reviewed from then on.

How often is the category reviewed?

The first review usually comes within the first year, then roughly yearly after that. Reviews can also be triggered by a big change, like a successful appeal, completed courses or approaching release. The person inside can ask their OMU when their next review is due, and put in an app requesting one if things have changed.

When does Cat D and open prison become realistic?

Broadly: closer to release, with settled behaviour, low escape risk and completed sentence plan work. Many people move to open conditions in the last couple of years of the time they will actually serve. Long and indeterminate sentences reach open conditions through Parole Board and risk decisions instead of the standard reviews.

Why does the category matter to family?

It shapes everything you experience: how far away the prison is, how relaxed visits are, whether day release and home leave are possible, and how easy phone contact is. A move from Cat B to Cat C to Cat D usually means better visits, more trust, and eventually days at home. It is worth caring about.

Can a category move be refused unfairly?

It can feel that way. The decision is about risk on paper: offence, behaviour, courses done, time left. If a review says no, the reasons must be given, and those reasons become the to-do list for the next one. Missing course places are a common blocker, and chasing a course place is a legitimate thing to push on.