Security Clearance Information for UK Prisons

Security Clearance

Personnel security vetting checks must be conducted on all directly and not directly employed people working in NOMS (National Offender Management Service). Working in the Offender Learning sector, you will be employed by third party education providers, but will still be required to undergo security clearance in order to work in the Offender Management Service.

Even if you are not working in a prison, but are involved in work within the sector, such as an administrator for an education provider, you are likely to need security clearance as you will regularly be working with confidential information.

Security vetting checks are not something that can be gained on an individual basis. In order to receive these checks, you must be sponsored by your employer. However, once you have been successfully vetted, these checks stay on your record. For instance, if you have worked at one prison for Milton Keynes College and wanted to transfer to another prison under a different education provider, you may not need to go through the full vetting procedure again.

Why are security clearance checks required?

  • To validate the identity of applicants is genuine and they have a lawful entitlement to work in the United Kingdom.
  • To avoid security breaches and ensure applicants, serving staff and workers are confirmed as being who they say they are, do not pose a threat to security and will not discredit the Service.
  • To assure the integrity of the organisation and safety of staff, workers, prisoners, offenders and visitors.
  • To provide ongoing assurance periodically through security vetting renewals, once a security vetting level expires. These checks will require staff and workers to complete new documentation.

Vetting checks are not required on ad-hoc visitors who visit a prison on an occasional basis provided that they are escorted at all times by a member of staff.

Personnel security checks generally consist of:

  • Confirming an applicant’s identity
  • Verification of current address and address history
  • Confirming an applicant’s nationality and entitlement to work in the United Kingdom
  • A criminal conviction check
  • Obtaining employment reference(s)
  • Personal countersignatory reference
  • Checking qualifications/Professional Registration where specified in the job advertisement
  • A declaration that individuals working for NOMS HQ, public and private prisons are not members of racist groups or organisations
  • Checks against the Individual Insolvency Register (IIR)
  • A residency compliance check for National Security Clearance applications
  • Previous NOMS engagement including any exclusion

Higher-Level Security

Different areas of the Offender Learning sector require a higher level of security clearance. For these higher level roles, National Security Clearance would be required. Any person working in a High Security Estate, such as a category A prison, would require a Counter Terrorism Check (CTC).

The CTC Clearance process involves the following mandatory stages:

  • Baseline Personnel Security Standard (BPSS), which is normally undertaken as part of the recruiting process)
  • Departmental / Company Records Check
  • Security Questionnaire
  • Criminal Record Check
  • Security Service Check

On completion of the vetting process, the information collected is assessed and a decision made to refuse or approve a CTC Clearance. Gaining CTC Clearance will normally require you to have been a resident in the UK for a minimum of 3 years.

Prison Categories & What They Really Mean  

Adult Male Prisoners

Categorisation is based on the level of risk a prisoner might pose to the public or national security should they escape and the likelihood of their making attempts to do so.

There are four different security categories:

Category A – Category A prisoners are those that would pose the most threat to the public, the police or national security should they escape. Security conditions in category A prisons are designed to make escape impossible for these prisoners.

Category B – Category B prisoners do not need to be held in the highest security conditions but, for category B prisoners, the potential for escape should be made very difficult.

Category C – Category C prisoners cannot be trusted in open conditions but are considered to be prisoners who are unlikely to make a determined escape attempt.

Category D – Category D prisoners can be trusted in open conditions.

Un-sentenced prisoners, or prisoners on remand awaiting trial, are generally housed in category B accommodation unless they have been provisionally classified as category A.

Female Prisoners and Young Offenders

Unless they have been deemed category A then female prisoners and young offenders are not categorised. They are only classified as suitable for open conditions or suitable for closed conditions.


Staff working within the Education Department of prisons are offered continual support to ensure that they feel safe working in the prison environment. Some Education areas have constant Officer presence.  The level of support provided may depend on the category within which you are working.

Each prison category comes with its own set of rewards and challenges, but the ability to make a difference remains the same. This may be over a longer term or short sentence period.