HMP & YOI Isis

A prison for young men in Thamesmead

In shortIsis is a publicly run category C training and resettlement prison and young offender institution for young men aged 18 to 27.

• Held at inspection577Operational capacity 628
• Aged 18 to 2147%
• Minority ethnic backgrounds70%
• Care leavers140783 men released in the previous year

GOV.UK describes Isis as a men's prison and young offender institution (YOI) in Thamesmead, South East London, named after the ancient name for the River Thames.

HM Inspectorate of Prisons (HMIP) says it opened in July 2010 as a public sector training prison for convicted men from London, and that since September 2021 it has held only young men aged 18 to 27.

In 2018 it was one of 10 prisons identified for investment to improve security and decency. HMIP's report on its inspection of 18 November to 4 December 2025 describes the task of the prison as category C training and resettlement for young men.

The Chief Inspector summarised the population as young men serving anything from a few weeks to life, and called Isis a difficult prison to run. Current capacity and population figures from the monthly bulletin are in the at-a-glance section above.

Operator

The prison is publicly run.

Providers

Oxleas provides physical and mental health care, Change Grow Live provides substance misuse treatment and People Plus is the education provider.

• Opened July 2010 in Thamesmead; young men aged 18 to 27 only since September 2021.
• Residential units are split across the Meridian and Thames houseblocks, with a Peace spur, a Growth spur and an induction unit.
• Prison group: London (HMPPS workforce statistics, 2026).

Latest inspection: November to December 2025

In shortIsis was rated good for respect and not sufficiently good for safety, purposeful activity and preparation for release, with the latter two improved from poor in 2022.

• SafetyNot sufficiently good
• RespectGood
• Purposeful activityNot sufficiently goodImproved from poor in 2022
• Preparation for releaseNot sufficiently goodImproved from poor in 2022

HMIP's unannounced inspection ran from 18 November to 4 December 2025 and the report was published on 9 March 2026, with the Chief Inspector's foreword dated January 2026. Respect was rated good, the top grade. The inspectors identified ten key concerns, five of them priorities.

The central change was a new behaviour management approach, called the Peace strategy. Previously, new arrivals were separated into small groups, often by gang affiliation, which severely restricted the regime.

Staff, safety and the officer experience

In shortThe 2026 report called staff-prisoner relationships a strength and the prison fully staffed, but use of force was too high.

• Prisoners with a named officer78%Surveyed prisoners
• PAVA drawn106 incidentsIn the previous year

Staffing is directly relevant to candidates and the 2026 report is unusually positive on it. The Chief Inspector wrote that relationships at Isis were a strength, and that with the support of the prison group director the governor had increased staffing levels and improved the capability of officers, leading to better retention and lower sickness.

The report says HMPPS leaders recruited more staff, increased overtime and brought in officers from other prisons, and that the prison was by then fully staffed with officers.

• Wing staff understood prisoners' individual circumstances.
• Reflective practice sessions run by the health provider's psychology team helped officers think through their experiences.
• A reverse mentoring scheme, in which prisoners mentor officers, was listed as notable positive practice.
• Leaders communicated with staff through operational briefings and a weekly newsletter that emphasised officers' roles in supporting and rehabilitating prisoners.

What the Independent Monitoring Board reported

In shortThe Board's latest report we could open covers calendar year 2024, before the changes inspectors saw in late 2025, and recorded rising violence.

• Prisoner assaults and fights419Up 31% on 2023
• Assaults on staff207Up 28% from 161
• Operational staff trained in PAVA87%144 staff issued with it by year end

The Independent Monitoring Board (IMB) for Isis publishes on a calendar-year basis. Its latest report we could open covers 1 January to 31 December 2024 and was published in June 2025. The prison attributed the rise in violence to the share of prisoners aged 18 to 21 growing from 32% to 44% during the year.

• 2024 was the first full year in which officers were trained in and issued with PAVA.
• Concerns raised about disproportionate use of PAVA on black prisoners and about cell bell response times.
• Officer availability often caused Christian Sunday services to be cancelled on the day.

Working at Isis and getting there

In shortIsis is in the outer London pay zone with no Band 3 market supplement listed on 3 October 2026, and is 10 officers above target.

• Trainee contract£38,84037-hour, starting pay a year, 2026/27 tables
• Longer contract£43,73941-hour
• Officers176 FTEAt 30 June 2026, Band 3 to 5, against a target of 166 (10 above)

Isis is in the outer London pay zone and is not on the HMPPS Band 3 market supplement list as checked on 3 October 2026. Compare the staffing figures with Belmarsh and Wormwood Scrubs.