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Aylesbury

Category C prisons · HMPPS functional group: Category C Trainer · Public sector · South West & South Central

HMP Aylesbury is a public sector prison in the Category C group. It sits in the lower middle of 50 similar prisons, with a likely position of 19th to 37th. Its official HMPPS rating is "Good". Based on official data to March 2026.

At a glance

Band among 50 category c prisonsLower middle
Likely position 19th to 37th of 50
Median 29th. The range is the 5th to 95th percentile over 1,000 re-weightings and measurement uncertainty.
PillarsSafety Lower middle Decency Upper middle Regime Lower middle Resettlement Lower middle
Official HMPPS rating (context)Good, score 62.8%
Not an input to our bands.

The measures behind the bands

Position is where the prison sits among its 50 peers on that measure alone (lower incident rates are better; higher grades and outcomes are better). For incident outcomes the position is after adjusting for who the prison holds.

Fourteen measures in four pillars, each pillar weighted equally.
MeasureThis prisonGroup median Position in groupData from
Safety pillar position: Lower middle
Prisoner-on-prisoner assaults106 per 1,000 prisoners
expected 156
175Top quarterApr 2025 to Mar 2026
Assaults on staff87.0 per 1,000 prisoners
expected 65.4
68.5Bottom quarterApr 2025 to Mar 2026
Self-harm incidents784 per 1,000 prisoners
expected 457
530Bottom quarterApr 2025 to Mar 2026
HMIP healthy prison test: safety3 (reasonably good)3.0Upper middleInspected Feb 2026
Prisoner survey: safety and security33.0Upper middleSurvey from Jun 2021
Decency pillar position: Upper middle
HMIP healthy prison test: respect3 (reasonably good)3.0Upper middleInspected Feb 2026
Prisoner survey: respect33.0Lower middleSurvey from Jun 2021
Regime pillar position: Lower middle
HMIP healthy prison test: purposeful activity2 (not sufficiently good)2.0Upper middleInspected Feb 2026
Prisoner survey: purposeful activity23.0Bottom quarterSurvey from Jun 2021
Prisoners in at least half-time purposeful activity70%66%Upper middle2025/26
Resettlement pillar position: Lower middle
Housed on the first night after release100%92%Top quarter2025/26
In employment six weeks after release10%15%Bottom quarter2025/26
In employment six months after release26%29%Lower middle2025/26
HMIP healthy prison test: preparation for release2 (not sufficiently good)3.0Bottom quarterInspected Feb 2026

Incidents compared with what we would expect

Rates are incidents per 1,000 prisoners over April 2025 to March 2026. The expectation is the average of a statistical model of who the prison holds (sentence length, remand, recalls, age, turnover, crowding) and the average of its HMPPS comparator prisons. Neither includes the prison's own result.

OutcomeActualModel expects Similar prisonsExpected (used)Actual ÷ expected Reading
Prisoner-on-prisoner assaults1061661461560.69×Lower than expected, but within what chance and recording differences could produce
Assaults on staff87.075.556.665.41.33×Higher than expected, but within what chance and recording differences could produce
Self-harm incidents7844884284571.71×Higher than expected, but within what chance and recording differences could produce

A flag appears only when the result is outside statistical limits and in the same direction under the model, the comparators and their average. It is a prompt to look, not a finding of fault. Counts of one or two incidents are suppressed in the source and estimated here.

Similar prisons

HMPPS names these prisons as the closest comparators, matching on age, sentence length, turnover, sex-offender share, complexity, building age and setting. Rates are per 1,000 prisoners; reoffending is the share of people released in April 2023 to March 2024 who reoffended within a year.

PrisonPrisoner assaultsStaff assaults Self-harmReoffendingOfficial rating
Aylesbury (this prison)10687.078423%Good
Coldingley23460.529222%Of concern
Featherstone13645.736933%Good
Onley20483.756737%Of concern
Stoke Heath17573.984039%Of concern
Buckley Hall17670.853234%Good
Morton Hall84.622.322011%Good
Cookham Wood67.467.4483–Good
Maidstone91.228.61236%Good
Average of similar prisons14656.642826%

Who the prison holds

These describe the population, not the prison's performance. They are what the expectations above adjust for. Averages over the four quarter-ends of 2025/26.

Share of populationThis prison Group median
Average population380724
On remand (untried or convicted, unsentenced)0%0%
Sentence under 12 months0%2%
Sentence 12 months to under 4 years2%22%
Sentence 4 years or more (determinate)64%48%
Life or IPP sentence14%5%
Recalled to custody20%18%
Aged under 2511%9%
Aged 50 or over14%15%
Releases in the year, per prisoner held0.050.63
Prisoners held in crowded accommodation0%13%

Remand is decided by courts and recall by probation and the Parole Board. They are context here, not something a prison controls.

Also shown, not scored

Staff sickness and resignations

Sickness: 10.0 days per full-time employee (HMPPS target 9; median for public prisons in its group 10.8).
Resignation rate: 8.7%.

Position among public-sector prisons in its group: sickness lower middle, resignations highest quarter. Related to quality in our tests, but the direction of cause is unclear, so it is not scored.

Reoffending after release

23.3% of 43 people released in April 2023 to March 2024 reoffended within a year. Expected given who is released and the mix of the prison and its comparators: 25.1%. Result: about as expected.

The Ministry of Justice says rates by releasing prison should not be used to assess prisons: they do not control for sentence or offender characteristics, and the prison of release may not be where the sentence was mainly served. About two years old.

Disorder incidents and finds

Per 1,000 prisoners, 2025/26This prisonGroup median
Incidents at height50.050.0
Barricades13.219.2
Drug finds352286
Weapon finds84.295.1
Mobile phone finds255100.0

Not scored. We cannot separate real disorder from differences in how incidents are recorded, and more finds can mean better searching rather than more contraband. Also recorded: 1 active concerted indiscipline incident.

Healthcare (Care Quality Commission)

Provider: Doctor PA Ltd; Time for Teeth Limited.
Latest compliance judgement: no compliance judgement published.

The CQC does not give prison healthcare a graded rating, so this is context only.

How current is this?

HMIP gradesInspected Feb 2026
Prisoner survey gradesSurvey from Jun 2021
Incident rates and workforceApril 2025 to March 2026
Resettlement outcomes2025/26 performance year
ReoffendingPeople released April 2023 to March 2024, followed for a year plus a six-month wait for court outcomes
Population mixQuarter-ends June 2025 to March 2026

Sources: data downloads and methodology. Think a figure is wrong? Tell us.