Background to the report

Electronic monitoring (‘tagging’) allows the police, courts, probation and immigration services to monitor offenders’ locations and compliance with court orders, and act if offenders breach their requirements. HM Prison and Probation Service (HMPPS), an agency of the Ministry of Justice (the Ministry), is responsible for tagging.

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Government regards electronic monitoring as a cost-effective alternative to custody which contributes to its goals to protect the public and reduce reoffending. It launched electronic monitoring in 1999. In 2011, in parallel to its normal tagging activities (the live service), HMPPS launched a transformation programme to improve efficiency and capability, mainly by introducing new technology and adding more sentencing options. It closed this programme in March 2022 and plans to widen the use of tagging over the next few years through a new expansion programme.

Scope of the report

This report sets out our assessment of HMPPS’s delivery of its electronic monitoring (‘tagging’) transformation programme, prompted by its cancellation of a key enabling project in 2021. It follows on from events in our previous report and focuses on HMPPS’s progress against objectives set out in its 2017 Full Business Case. We also examined how it has applied learning and how it plans to address risks in its expansion programme. We did not examine suppliers’ performance in managing the current live tagging service.

Report conclusions

HMPPS has launched new services, extended tagging to new groups of offenders and taken pragmatic steps to reduce delivery risks. But it has not achieved the fundamental transformation of tagging services it intended and has wasted £98 million through its failed attempt to develop the Gemini case management system. It did not manage the implications of its complex delivery model effectively, set overly prescriptive requirements and did not perform its role as systems and service integrator effectively. HMPPS’s decision to stop Gemini in 2021 was well-founded in the circumstances and protected the taxpayer from further losses. However, its lack of focus on monitoring benefits and continued poor evidence base means that – more than 10 years into the programme – Parliament still does not have a clear view on what it has achieved or whether electronic monitoring is an effective intervention. To date, HMPPS has not achieved value for money.

HMPPS has identified lessons from its management of the transformation programme. Its plans for re-procurement and transition to the new service mean it is now better placed to avoid repeating past mistakes. However, it has limited time to make the transition, and at this early stage it does not yet know how easy it will be to integrate prospective suppliers’ work. Ultimately, achieving value for money in the future will depend on HMPPS delivering a reliable, responsive and cost-effective service to stakeholders, supported by evidence that tagging brings proven reductions in reoffending and that more offenders are diverted from prison. HMPPS is taking welcome steps to identify what data and information it needs to build the evidence base. Still, significant work remains to demonstrate the value of electronic monitoring in protecting the public and reducing reoffending.

"HMPPS has extended tagging to new groups of offenders, but it has not achieved the fundamental transformation of tagging services it intended. Significant work remains to strengthen the evidence base and understand the impact of electronic monitoring on reoffending. HMPPS must learn lessons so it can deliver a reliable, responsive and cost-effective service that protects the public.”

Gareth Davies, the head of the NAO


Publication details

Press release

View press release (8 Jun 2022)

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