Amid ongoing discussions about prison overcrowding in England and Wales, the National Audit Office (NAO) has raised alarms regarding the rapid rollout of electronic tagging. Currently, around 28,700 individuals are under electronic surveillance, a figure that has doubled in just five years. The NAO’s latest report suggests that without significant improvements to the system, public safety could be compromised as the government plans to increase the number of monitored offenders to approximately 22,000 annually starting in 2027.
Growing Reliance on Electronic Monitoring
The UK government’s strategy to alleviate pressures on prisons involves expanding the use of electronic tagging. However, the NAO warns that the existing system is already under strain and may not be equipped to handle the proposed expansion effectively. The Ministry of Justice (MoJ) and the HM Prison and Probation Service (HMPPS) face pressing challenges, particularly concerning the number of individuals who remain unmonitored despite being tagged.
As of March 2026, HMPPS was scrutinising about 8,900 cases—24% of those tagged—to ascertain how many were not being actively monitored. In contrast, the MoJ claims that only around 5,450 cases fall into this category. The discrepancy between these figures raises significant concerns about the reliability of the monitoring system.
Performance Issues and Staffing Shortfalls
The report also highlights troubling performance issues related to Serco, an external contractor responsible for implementing the tagging system. Between August 2024 and July 2025, there were notable delays in tagging individuals and notifying officials of potential breaches. During this challenging period, a backlog of visits for fitting, checking, or removing tags soared to 7,000 in October 2024, before dropping back to fewer than 400 the following month.
Despite recent improvements in timeliness—Serco reportedly met a 95% target for visits in February 2026—only 62% of individuals were successfully tagged during the contractor’s two attempts. Adding to the concerns, the NAO identified an estimated shortfall of approximately 2,200 probation staff, further complicating the ability to safely scale up the electronic monitoring initiative.
Calls for Reform and Investment
As the government plans to invest up to £175 million in the expansion of electronic tagging between 2026 and 2029, experts and public figures are urging caution. Gareth Davies, head of the NAO, emphasised the need for the MoJ and HMPPS to address identified inefficiencies before proceeding with any further expansion. Sir Geoffrey Clifton-Brown, chair of the public accounts committee, echoed these sentiments, stating that the lack of clarity on unmonitored individuals presents unknown risks to public safety.
Pia Sinha, chief executive of the Prison Reform Trust, expressed her concerns, warning that viewing electronic monitoring as a panacea could lead to significant oversights. She called for any expansion to be paired with increased investment in the probation system, stronger safeguards, and a clear definition of success.
In response to the criticisms, a spokesperson for the MoJ acknowledged that the current tagging system has faced challenges, noting improvements in installation rates since 2024. They highlighted the government’s commitment to public safety through enhanced monitoring and victim protection systems, along with a substantial investment in the probation sector.
Why it Matters
The expansion of electronic tagging in England and Wales is a pivotal aspect of the government’s strategy to combat prison overcrowding. However, the serious concerns raised by the NAO underline the importance of ensuring that such systems are not only effective but also safe. As reliance on technology grows, it is crucial that reforms are implemented to maintain public confidence and security, ensuring that those under supervision can reintegrate successfully into society. The stakes are high, and the government must act decisively to address these vulnerabilities before embarking on further expansions of electronic monitoring.