Guidance

How the HMPPS Core Person Service can benefit from a Cross-Government Person Domain Data Standard

Published 30 June 2026

1. Context

The Core Person Record (CPR) service within HMPPS aims to create a single authoritative identity for individuals across the prison and probation system. Currently, person data is fragmented across multiple systems leading to duplication, inconsistent data, and manual effort. CPR’s vision is to:

• remove duplication of person information across HMPPS services

• provide a canonical record that supports better decisions and reduces risk

• enable integration with wider Criminal Justice System (CJS) services

2. Current Challenges

• Inconsistent Data Structures: Each system uses different formats for core attributes like names, addresses, and identifiers, making integration difficult.

• No Common Data Language: Lack of a unified standard for person attributes (e.g. aliases, reference data for protected characteristics) leads to ambiguity and errors.

• Fragmented Governance: no cross-government approach to managing person data, resulting in siloed decisions and duplication of effort.

• Limited Interoperability: Current models do not support seamless data sharing across justice and wider government services, creating barriers for future integrations.

3. Use Case Analysis

The development of the Core Person Record (CPR) service would have been significantly accelerated if an authoritative, pre-existing data domain model had been available at the project’s inception. Instead of being forced into the role of “accidental architects” for HMPPS data structures, the team could have focused immediately on technical implementation. Having a higher-authority standard would have bypassed the estimated 1.5 years of analysis that was required to organise & establish a comprehensive domain for basic attributes like names, addresses, and protected characteristics.

A higher-authority model would have also provided a robust framework for internal decision-making and governance, which were recurring challenges throughout development. One of the primary lessons learned was that the lack of a clear data standard led to discrepancy within the same organisation, making processes entrenched and almost impossible to change once established. If a cross-government standard model had been established sooner, it would have served as an undeniable “single source of truth” with its own weight of authority that could have helped focus direction sooner. By providing the standardized “Data Glossary” and “Data Dictionary” defined in the DEGOP standard, it would have given the project the exact tools needed to align definitions and focus direction from the start.

Another benefit would have been to provide critical reassurance that the Core Person Record was interoperable by design from the very beginning. By aligning with a higherauthority “Person” model, the project would have gained the technical confidence that its data structures were already fundamentally compatible with major crossgovernment partners like the DWP, Home Office, and Police. This alignment would have removed the uncertainty surrounding future expansions, guaranteeing that sharing data would be a straightforward extension of the service rather than a looming engineering hurdle. Crucially, since linking into these other external systems is part of our roadmap, we would have benefited from the certainty that those systems would eventually align to this same model.

Ultimately, having an established data domain standard sooner would have acted as a powerful strategic catalyst. It would have provided the visual representation and concept data model needed to bridge the gap between legacy systems and a modern, unified identity service much faster. By shifting the focus from “what” the data structure should be to “how” to implement an existing standard, the CPR project could have realized its goals of reducing administrative burden, eliminating duplicates, and improving public safety far earlier in its lifecycle.