The UK’s electronic tagging system for offenders is facing significant challenges, raising concerns about public safety and the effectiveness of monitoring offenders in the community. A recent report from the National Audit Office (NAO) highlighted critical shortcomings in the government’s electronic monitoring programme, which has been central to efforts to alleviate overcrowding in prisons.

As of March 2026, approximately 37,600 individuals were subject to electronic tagging orders, but an estimated 14 percent—around 5,450 individuals—had not been fitted with tags, according to the Ministry of Justice (MoJ). However, the NAO’s findings suggest the actual number of untagged or unmonitored offenders could be higher. The watchdog pointed to a review of nearly 9,000 cases where courts had ordered tagging but no devices had yet been fitted or confirmed as active. The MoJ disputed some of these figures, noting that about 3,500 had completed their tagging periods, but the gap in accurate data remains a concern.

The report also identified operational weaknesses in the contract with Serco, the firm responsible for installing and managing tags. In nearly 40 percent of cases, Serco failed to successfully tag offenders after two home visits, citing reasons such as offenders being absent or refusing to comply. Additionally, there is a significant delay in reporting breaches of tagging conditions—ranging from 29 to 53 hours—which allows offenders to remain unmonitored for extended periods after committing potential violations, including curfew breaches, attempts to remove tags, or entering exclusion zones.

Authorities have further noted inconsistencies in how breaches are treated. Both serious and minor infringements often receive similar responses, and nearly half of recorded breaches result in no further action despite their potential gravity. Police and probation officials have expressed frustration over insufficient resources and information, impeding timely responses to alerts. Some criminal suspects who breach tagging conditions have reportedly been re-released with limited consequences, raising additional reservations about enforcement.

The government plans to expand electronic tagging substantially, with the number of tagged individuals expected to increase by 22,000 per year from 2027. This expansion is tied to Labour-led criminal justice reforms that seek to replace jail sentences with community-based punishments as a means to reduce prison overcrowding. Among those affected will be serious offenders, including killers and rapists, released under revised early release schemes.

Public accounts committee chair Sir Geoffrey Clifton-Brown warned that expanding a system already experiencing significant operational problems risks public safety and wastes taxpayer money. He emphasized the government’s lack of reliable data on unmonitored offenders as particularly troubling.

In response, a Ministry of Justice spokesperson acknowledged ongoing challenges but highlighted progress made, including a nearly 50 percent increase in successful tag installations since 2024 and a substantial investment of £100 million to improve electronic monitoring. The MoJ also pointed to ongoing recruitment efforts within the Probation Service, with over 3,500 new trainee probation officers hired in recent years to bolster supervision capacity.

Despite these efforts, the NAO report underscores persistent inefficiencies and risks that raise questions about the safety and viability of scaling up electronic tagging as a primary tool to manage offender populations outside custody. The watchdog advised addressing identified weaknesses before implementing further expansion to ensure effective public protection.