Nearly 9,000 offenders in England and Wales required to wear an electronic monitoring tag did not have one as of March 2026, according to a damning report by the National Audit Office – a figure the Ministry of Justice disputes but which the watchdog insists could be just the tip of the iceberg.
The NAO found that prison authorities were reviewing some 8,900 cases of individuals recorded as having an active monitoring order but no tag. These cases are likely to include violent offenders and prisoners released from jail who need to be checked on – potentially even serious criminals such as rapists and murderers. The Ministry of Justice, however, pushed back, saying its own review puts the number at 5,450. It argued that the NAO figure represented the total number of cases being checked, not the confirmed unmonitored.
“NAO finds nearly 9,000 offenders without electronic tags; MoJ disputes figure but watchdog warns risk to public protection.”
The report, which called the current system “inefficient”, said some of the 8,900 cases would include people registered as tagged by mistake. But the NAO also warned that the real number slipping through could be “significant”. People can end up unmonitored for a variety of reasons: system errors, refusal to wear a tag, delays in fitting, or arrest and tag removal. But the watchdog made clear it also includes those who were never fitted with a tag when they should have been.
As of March 2026, 28,700 people were recorded as tagged across England and Wales, using three types of devices: curfew tags, location tags, and alcohol tags. The NAO’s chief, Gareth Davies, said the system is not working effectively. “Electronic monitoring is central to managing pressures on prisons, but it is not working effectively, creating risks to public protection,” he said. “Improvements are required to ensure that those who should be monitored are monitored and that breaches are responded to effectively.”
The report also flagged that police and probation staff often lack the information or capacity to respond quickly to breaches. In response, the Ministry of Justice said: “Public protection is our priority, which is why we’re investing £100m in electronic monitoring, tagging offenders before release for the first time and strengthening victim protections via new alert systems – all of which will help cut the number of unmonitored offenders.”
The watchdog’s findings raise uncomfortable questions about whether the tagging system meant to ease prison pressures is instead leaving dangerous individuals unmonitored on the streets.