Criminal justice system: data standards forum guidance
Source: gov.uk (2025-09-15)

How to use the common data standards for the criminal justice system (CJS) in England and Wales.

Overview

The CJS in England and Wales uses a commonly agreed set of data standards to support ICT communications between the systems used by criminal justice organisations (CJOs). These data standards are designed specifically to support the operation of the CJS. They are to be used with open data standards as defined in the government’s Open Standards Principles (https://www.gov.uk/government/publications/open-standards-principles). The government’s open standards are selected by the Cabinet Office standards hub (http://standards.data.gov.uk/).

Common data standards are used by CJOs, their ICT suppliers and potential suppliers wishing to bid for CJS contracts. They are also used to support the data analytics of criminal justice information.

These standards are available to the public under the Open Government Licence (https://www.nationalarchives.gov.uk/doc/open-government-licence/).

The selection of the CJS data standards is made by the CJS Data Standards Forum (https://www.gov.uk/government/groups/criminal-justice-system-data-standards-forum). This is a technical forum which has representatives from the principal CJOs.

Geography

The CJS data standards apply to all CJOs in England and Wales.

Data standards catalogue

(https://assets.publishing.service.gov.uk/media/5e3853baed915d095784f4e4/cjs-data-standards-catalogue-6.pdf)

CJS data standards catalogue 6.0 (https://assets.publishing.service.gov.uk/media/5e3853baed915d095784f4e4/cjs-data-standards-catalogue-6.pdf)

PDF, 1.86 MB, 155 pages

(https://assets.publishing.service.gov.uk/media/5a756710e5274a1baf95e4b2/cjs-data-standards-catalogue-5.0.pdf)

CJS data standards catalogue 5.0 (https://assets.publishing.service.gov.uk/media/5a756710e5274a1baf95e4b2/cjs-data-standards-catalogue-5.0.pdf)

PDF, 1.48 MB, 161 pages

This file may not be suitable for users of assistive technology.

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The catalogue contains data standards to support the exchange of criminal justice information between different CJOs. Only the latest version of the catalogue is current. Earlier versions of the catalogue are provided to:
- track changes between the different versions to help organisations understand the practical implications of the ‘before’ and ‘after’ versions of altered standards
- provide historical versions of the standards, especially those with lists of values, which may be used for historical reporting purposes and statistical analysis of historical data
How to use the catalogue

Use the CJS data standards when sending criminal justice information from one CJO to another. The data standards don’t have to be used within CJOs.

Options for implementing the CJS data standards

Each CJO can decide how to implement the standards. It can either
- map its internal data standards to the criminal justice data standards when sending information to a different CJO
- adopt one or more of the CJS data standards as its internal data standard. This avoids the costs and performance impacts of mapping to the CJS data standards when sending information to a different CJO
Each CJO should make its decision on how to use the CJS data standards based on the contribution those standards make both in terms of the system’s functional and non-functional requirements and in the context of a total cost of ownership model.

Ensuring CJS data standards implementation

To ensure that the CJS data standards are used, CJOs should contractually specify that:
- suppliers comply with the CJS data standards for the transmission of information both for ICT development and during service management
- ICT suppliers monitor the CJS data standards web pages and always use the latest versions of those standards
- the latest version of the CJS data standards is downloaded directly from the CJS data standards web pages
- suppliers subscribe to receive updates to the CJS data standards
Subscribing to updates of this page will give you notifications of:
- new versions of the catalogue
- new versions of standards which have yet to be entered into a new version of the catalogue
- updates to code lists
CJOs should also consider mapping the data standards to any supporting technical documentation such as logical data models and interface specifications.

Types of data standard

The catalogue includes 3 different types of data standard:
- formatting standards
- organisational structure standards
- reference data standards
Formatting standards

These are concerned with the structure of a common type of data item such as dates or notes fields in a message or a database table. Use the common format for such items when you send information between different organisations. Formatting standards don’t have lists of actual values associated with them.

Organisational structure standards

Organisational structure standards describe the logical structure of an organisation. You can use these to work out the allocation of responsibilities in that they uniquely identify organisational units. This helps the correct transmission of information from one part of a CJO to part of a different CJO. Use organisational structure standards also to support reporting.

Reference data standards

A reference data standard categorises other data by using a commonly accepted list of mutually exclusive values. For example, a record for a person might include the person’s gender by use of the reference data standard ‘Gender Type Code’. Using a common list of such values across the CJS helps create a shared understanding of the correct interpretation of such classifications.

Code lists for data standards

Many of the lists for the reference data standards and organisational structure standards are comparatively small. In those cases the complete list for that standard is given in the catalogue.

A smaller number of standards are either too large to put in the catalogue or are subject to comparatively frequent change. In either of these cases the CJO that stewards the specific standard must provide that list. Each data standard in the catalogue specifies the organisation that acts as its steward.

Where the stewarding body is the Data Standards Forum itself, or where the body falls under the remit of the Ministry of Justice (MOJ), the lists of the data values are provided here.

Code lists for reference data standards

The lists of data values for reference data standards managed either by the Data Standards Forum or MOJ which are not in the catalogue are:
- CJS result codes v.10 (https://assets.publishing.service.gov.uk/media/60e5d07f8fa8f50c70bc6587/cjs-result-codes-10.ods) (ODS, 63.6 KB)
- CJS result codes v.10 (https://assets.publishing.service.gov.uk/media/60e5d091e90e0764c7950b73/cjs-result-codes-10.xlsx) (MS Excel Spreadsheet, 96.5 KB)
- Home Office classification
- Indictment cross reference
- CJS national court codes 12.ods (https://assets.publishing.service.gov.uk/media/67a9ef0a31fb10faa3148477/CJS_National_Court_Codes_12.ods) (ODS, 63.9 KB)
- CJS national court codes 12.xls (https://assets.publishing.service.gov.uk/media/67a9ef35acab8c9492a461ee/CJS_National_Court_Codes_12.zip) (ZIP, 105 KB)
- Postcode to national court code map 10.0 (https://assets.publishing.service.gov.uk/media/617fbebbe90e07197f18fe0d/postcode-national-court-code-map.ods) (ODS, 113 KB)
- CJS result qualifiers v8 (https://assets.publishing.service.gov.uk/media/5f1eea2dd3bf7f596b135aec/cjs-result-qualifiers-v8.xlsx) (MS Excel Spreadsheet, 34.2 KB)
- CJS Offence Index: September 2025 (https://assets.publishing.service.gov.uk/media/68c81aec995dfd01bff0bed5/offences-active-cjs-index-september-2025.csv) (CSV, 3 MB)
Code lists for organisational structure standards

The lists of data values for organisational structure standards are all elements of the ‘Organisation Unit (OU) Identifier’ structure of the data standards catalogue. The top level codes are specified in the catalogue. Elements below the top level are managed separately by the various CJOs. The code lists for HMCTS magistrates and Crown Courts are given below:

(https://assets.publishing.service.gov.uk/media/6756fee87ec19a3516f79a50/CJS_Courts_BC_OU_Codes_v37.ods)

CJSE Courts BC OU Codes v37.0 (https://assets.publishing.service.gov.uk/media/6756fee87ec19a3516f79a50/CJS_Courts_BC_OU_Codes_v37.ods)

ODS, 117 KB

This file is in an OpenDocument (https://www.gov.uk/guidance/using-open-document-formats-odf-in-your-organisation) format

(https://assets.publishing.service.gov.uk/media/6756febc7ec19a3516f79a4f/CJS_Courts_BC_OU_Codes_v37.xlsx)

CJSE Courts BC OU Codes v37.0 (https://assets.publishing.service.gov.uk/media/6756febc7ec19a3516f79a4f/CJS_Courts_BC_OU_Codes_v37.xlsx)

MS Excel Spreadsheet, 149 KB

This file may not be suitable for users of assistive technology.

If you use assistive technology (such as a screen reader) and need a version of this document in a more accessible format, please email xxx@xxx.xx (mailto:xxx@xxx.xx). Please tell us what format you need. It will help us if you say what assistive technology you use.

CJS standards and open standards

The CJS data standards are sector specific. Any interested party can use them, subject to the Open Government Licence (https://www.nationalarchives.gov.uk/doc/open-government-licence/some%20reference%20to%20Open%20Government%20Licence). They are different from the open standards selected for government IT. The open standards are at the Cabinet Office’s standards hub (http://standards.data.gov.uk/).

If there’s a choice between the 2, then open standards must take precedence as they are mandated by Cabinet Office policy (https://www.gov.uk/government/publications/open-standards-principles/open-standards-principles).

Engaging with the Data Standards Forum

The CJS Data Standards Forum (https://www.gov.uk/government/groups/criminal-justice-system-data-standards-forum) undertakes technical management of the CJS data standards. All of the principal CJOs are represented on the forum.

If you’re a member of a CJO, contact your forum representative for any issues related to CJS data standards. This includes queries about particular standards, change requests to existing standards or requirements for new standards.

Suppliers should contact their contracting CJO to raise any issues relating to the CJS data standards. In turn, the CJO should contact their representative on the forum.

If your CJO doesn’t have a representative and you want to get involved, contact the chair at xxx@xxx.xx (mailto:xxx@xxx.xx)

Changes to the standards

There are 2 types of process which could result in a change to the CJS Data Standards catalogue:
- a CJO can raise a change request to create, update or retire a data standard
- forum representatives may initiate changes as part of a continued review process of the contents of the catalogue.
Continued review

The Data Standards Forum continuously reviews the catalogue as a standing action. The aim is to produce a set of standards that is as small as possible while still being fit for purpose. It contributes to the ‘Value for Money’ agenda by focusing on existing business need to reduce the costs of compliance. Each forum meeting reviews a number of the standards to ensure that they’re relevant and meet the business need.

Notification of changes

Changes to standards will be posted here. They will stay here until they’ve been included into a new version of the catalogue.