Open prisons
Open prisons have minimal perimeter security and hold people assessed as low risk (Category D for adult men; women and young offenders are simply 'open'). The Open group has 14 prisons in our dataset: 13 run by HMPPS; 1 run by the Scottish Prison Service. By designation they are 9 HMP, 4 HMP & YOI, 1 SPS. This is HMPPS's role label for the prison, not the security category of any individual prisoner.
- Prisons
- 14 All publicly run
- Operational capacity
- 5,079 Itemised sites, 24 Aug 2026
- Market supplements
- 2 HMPPS pay page, 3 Oct 2026
- Regions
- 9 Geographic regions
The Open group in numbers
Across the 11 sites with an itemised figure, HMPPS reports an operational capacity of 5,079 and a population of 4,834 (95%) at 24 August 2026. The largest is HMP Sudbury at 661; the smallest is HMP Kirklevington Grange at 187; the highest occupancy is HMP & YOI Thorn Cross at 100% of its operational capacity. 2 sites here share a combined HMPPS figure with a neighbour and are left out of these totals.
Of the 13 HMPPS-run prisons, 13 in the National zone. Band 3 entry pay on 39 hours runs from £37,131 (Sudbury) to £40,131 (Spring Hill) once any supplement is counted. On the HMPPS market supplement list: Spring Hill (£1,500), Standford Hill (£1,500).
HMPPS's 2025/26 performance ratings cover 13 of them: 10 outstanding, 3 good. The highest overall score is 97.5% (Haverigg) and the lowest is 72.6% (Kirkham).
13 prisons have an HMIP report on record; 13 have four graded tests from a full inspection. On safety the latest full inspections gave 11 good, 2 reasonably good, 0 not sufficiently good and 0 poor. 10 had every test at reasonably good or better. One was graded poor on at least one test (Leyhill). The newest report is Kirkham (September 2025) and the oldest is Spring Hill (August 2022).
Staffing against target (Band 3 to 5, hours-adjusted FTE, 30 June 2026) is published for 12 of them: 36 FTE short in total, with Hollesley Bay furthest below (-12) and 1 over target. A gap is a staffing measure, not advertised vacancies.
Geographically the group is spread across North West (3), South East (3), East Midlands (2), Yorkshire and the Humber (1), East of England (1), Wales (1), Scotland (1), North East (1), South West (1).
Counted from our dataset, 3 October 2026.
Prison by prison: key numbers
| Prison | Capacity | Full | HMPPS rating | HMIP safety | Latest HMIP report | 39h entry pay (* with supplement) |
|---|---|---|---|---|---|---|
| Sudbury | 661 | 88% | 3 of 4, 76.2% | reasonably good | October 2023 | £37,131 |
| Hollesley Bay | 655 | 99% | 4 of 4, 83.1% | good | July 2024 | £37,131 |
| Kirkham | 618 | 96% | 3 of 4, 72.6% | reasonably good | September 2025 | £37,131 |
| Spring Hill | 546 | n/a | 3 of 4, 73.6% | good | August 2022 | £40,131 * |
| Haverigg | 544 | 94% | 4 of 4, 97.5% | good | July 2025 | £37,131 |
| Prescoed | 496 | n/a | 4 of 4, 90.0% | good | August 2025 | £37,131 |
| Leyhill | 474 | 99% | 4 of 4, 82.2% | good | September 2023 | £37,131 |
| Standford Hill | 464 | 87% | 4 of 4, 82.8% | good | February 2025 | £40,131 * |
| Thorn Cross | 429 | 100% | 4 of 4, 84.2% | good | August 2023 | £37,131 |
| Ford | 389 | 97% | 4 of 4, 87.0% | good | July 2023 | £37,131 |
| Hatfield | 358 | 97% | 4 of 4, 95.5% | good | October 2024 | £37,131 |
| North Sea Camp | 300 | 98% | 4 of 4, 85.6% | good | August 2023 | £37,131 |
| Kirklevington Grange | 187 | 96% | 4 of 4, 90.8% | good | December 2024 | £37,131 |
| Castle Huntly | n/a | n/a | n/a | n/a | none found | SPS scale |
All Open prisons
| Prison | Region | Town | Type | HMPPS group | Run by | Capacity | Band 3 entry, 39h | Supplement |
|---|---|---|---|---|---|---|---|---|
| HMP & YOI Hatfield | Yorkshire and the Humber | near Doncaster (Hatfield Main and Hatfield Lakes) | HMP & YOI | Open | Public (HMPPS) | 358 | £37,131 | None |
| HMP & YOI Hollesley Bay | East of England | Woodbridge | HMP & YOI | Open | Public (HMPPS) | 655 | £37,131 | None |
| HMP & YOI Prescoed | Wales | Coed-y-Paen, near Pontypool | HMP & YOI | Open | Public (HMPPS) | 496 | £37,131 | None |
| HMP & YOI Thorn Cross | North West | Appleton Thorn, Warrington | HMP & YOI | Open | Public (HMPPS) | 429 | £37,131 | None |
| HMP Castle Huntly | Scotland | Longforgan, near Dundee | SPS | Open | Public (SPS) | n/a | n/a | n/a |
| HMP Ford | South East | Arundel | HMP | Open | Public (HMPPS) | 389 | £37,131 | None |
| HMP Haverigg | North West | near Millom | HMP | Open | Public (HMPPS) | 544 | £37,131 | None |
| HMP Kirkham | North West | Kirkham | HMP | Open | Public (HMPPS) | 618 | £37,131 | None |
| HMP Kirklevington Grange | North East | Yarm / Stockton-on-Tees | HMP | Open | Public (HMPPS) | 187 | £37,131 | None |
| HMP Leyhill | South West | near Wotton-under-Edge | HMP | Open | Public (HMPPS) | 474 | £37,131 | None |
| HMP North Sea Camp | East Midlands | Boston | HMP | Open | Public (HMPPS) | 300 | £37,131 | None |
| HMP Spring Hill | South East | Grendon Underwood | HMP | Open | Public (HMPPS) | 546 | £40,131 | £1,500 |
| HMP Standford Hill | South East | Isle of Sheppey | HMP | Open | Public (HMPPS) | 464 | £40,131 | £1,500 |
| HMP Sudbury | East Midlands | near Ashbourne | HMP | Open | Public (HMPPS) | 661 | £37,131 | None |
Related
Read prison categories explained for how Category A to D and the functional groups fit together, the UK prisons list, the Category A prisons guide, or compare sites in the prison finder.
- East Midlands
- East of England
- North East
- North West
- Scotland
- South East
- South West
- Wales
- Yorkshire and the Humber
Other functional groups
Open prisons: FAQs
What is a Open prison?
Open prisons have minimal perimeter security and hold people assessed as low risk (Category D for adult men; women and young offenders are simply 'open'). The label is HMPPS's functional group from its 2025/26 performance ratings: it describes a prison's role, not the security category of each prisoner.
Which prisons are in the Open group?
Hatfield, Hollesley Bay, Prescoed, Thorn Cross, Castle Huntly, Ford, Haverigg, Kirkham, Kirklevington Grange, Leyhill, North Sea Camp, Spring Hill, Standford Hill and Sudbury.
Do Open prisons pay officers more?
13 in the National zone. Band 3 entry pay on 39 hours runs from £37,131 (Sudbury) to £40,131 (Spring Hill) once any supplement is counted. On the HMPPS market supplement list: Spring Hill (£1,500), Standford Hill (£1,500).
Are any Open prisons privately run?
No. All are publicly run.
How big is the Open group?
14 establishments with an operational capacity of 5,079 across those with an itemised figure (24 August 2026).