Can a GPS Tracker Be Blocked? Jammers, UK Law and What Fleets Should Do

Every fleet operator who fits trackers eventually asks the same thing. If a thief, or one of your own drivers, really wanted to, could they just switch the tracker off?

The honest answer is that a GPS signal can be blocked. Cheap jammers exist, they’re illegal to use in the UK, and they still turn up in stolen vehicles and occasionally in company ones. The good news is that a well-set-up tracking system doesn’t go quiet without telling you, and that’s what actually matters.

The short answer

Yes, a GPS jammer can stop a tracker getting a location fix. Using one is a criminal offence in the UK. And a decent fleet tracker treats a sudden loss of signal as something worth alerting on, so jamming tends to flag the vehicle rather than hide it.

Who actually jams trackers

There are two very different people you’re dealing with.

Theft gangs. Organised vehicle thieves know trackers are common on fleet, rental and high-value vehicles. Blocking the signal while they move a car to somewhere quiet buys them time to find and remove the tracker, or to get the vehicle into a container before anyone knows it’s gone.

Your own drivers. Less dramatic, more common. A driver who wants to hide personal use, a side job, a long break or where they really were during a shift might try a plug-in jammer from the internet. It’s rare, but when it happens it’s usually a sign of a bigger problem.

The answer to both is the same: make sure a tracker going quiet is treated as an event, not a gap in the data.

Are GPS jammers illegal in the UK?

Yes, using one is. Ofcom is clear that using a jammer to interfere with wireless signals is an offence under the Wireless Telegraphy Act 2006, unless it’s specifically authorised. The maximum penalty is up to two years in prison, an unlimited fine, or both.

The law is also getting tougher on the devices themselves. The Crime and Policing Act 2026, which received Royal Assent in April 2026, creates a new offence of possessing, importing, making, adapting or supplying an electronic device where there’s reasonable suspicion it will be used to steal a vehicle. Signal jammers, relay boxes and CAN injection kits are the devices it’s aimed at. The maximum sentence is five years. At the time of writing, legislation.gov.uk lists that section as not yet in force, so check the current position before relying on it.

This isn’t legal advice. If you’re dealing with a specific case, speak to a solicitor.

What it means if a driver jams a company tracker

If a driver uses a jammer in a company vehicle, they’ve committed a criminal offence and almost certainly breached their employment or rental terms. For most operators, that’s a disciplinary matter at the very least.

A few things make it far easier to deal with if it ever happens:

• Have a written vehicle policy that says vehicles are tracked, why, and that tampering with or blocking the tracker is gross misconduct.
• Tell drivers about tracking up front. UK data protection rules expect employers to be open about monitoring, and it’s much harder for anyone to argue they didn’t know.
• Keep the alerts and history. A record of exactly when and where a vehicle’s signal dropped, and when it came back, is what turns a suspicion into something you can act on.

Get advice from HR or an employment solicitor before you take action against a driver. How you handle it matters as much as what happened.

How fleets stay visible when someone tries

You can’t stop someone buying a jammer. What you can do is make sure it doesn’t buy them much.

Alerts when the signal disappears. A tracker that suddenly stops getting a GPS fix while the vehicle is still powered, or in the middle of a journey, is suspicious. Good fleet platforms flag that straight away rather than just showing a gap on the map later.

The last known location. Even if the signal drops, you know exactly where the vehicle was a moment before and which way it was heading. In a theft, that’s where the police start.

Power and unplug alerts. Jamming often comes with an attempt to find and pull the tracker. Hardwired units alert if power is cut, and they’re much harder to find than a plug-in OBD unit. Our hardwired tracker guide explains why.

A second device. A small battery-powered tracker hidden elsewhere in the vehicle gives you another chance if the main unit is found and removed. We cover where trackers should go in where do you put a tracker on a car.

An immobiliser. A jammer can hide a vehicle. It can’t start one. A ghost immobiliser doesn’t rely on GPS or a radio signal, so blocking the tracker does nothing to help a thief drive the vehicle away. Our post on whether a ghost immobiliser can be bypassed covers how the two work together.

Can thieves find a hidden tracker?

Sometimes. Detectors that pick up a tracker’s mobile signal are easy to buy, and a thief who has the vehicle somewhere private for a few hours can strip trim until they find a unit. That’s exactly why a single tracker in an obvious spot isn’t enough on high-risk vehicles.

The fix is the same layered approach: a hidden hardwired tracker, a backup unit somewhere else, alerts when either goes quiet, and an immobiliser so the vehicle can’t simply be driven away while someone hunts for them.

What to do now

• Check your tracking platform alerts on signal loss and power loss, and that those alerts go to someone who’ll act on them out of hours.
• Make sure high-theft vehicles have a hardwired tracker, not just an OBD plug-in.
• Consider a backup battery tracker on your most at-risk vehicles.
• Put tracking and tampering in writing in your driver or rental terms.
• Pair tracking with an immobiliser on anything a gang would want.

For the wider picture on how gangs target fleets, see our guide to relay attack car theft.

Frequently asked questions

Can a GPS tracker be blocked? Yes. A GPS jammer can stop a tracker getting a location fix. But using one is illegal in the UK, and a well-set-up fleet tracker will alert you when its signal suddenly disappears.

Are GPS jammers illegal in the UK? Using one is an offence under the Wireless Telegraphy Act 2006, with a maximum penalty of two years in prison and an unlimited fine. The Crime and Policing Act 2026 adds an offence of possessing or supplying devices for vehicle theft, including jammers, though legislation.gov.uk lists it as not yet in force at the time of writing.

Can an OBD tracker be blocked? It can be jammed like any GPS tracker, but the bigger weakness is that it’s easy to unplug from the diagnostic port. On high-theft vehicles, use a hardwired tracker instead or as well.

Can thieves detect a GPS tracker? They can try, using cheap detectors or by stripping trim. A well-hidden hardwired unit, a backup tracker and alerts on power or signal loss make that much harder.

What should I do if a driver is using a jammer? Keep the tracking history showing when and where the signal dropped, check your vehicle policy, and take advice from HR or an employment solicitor before acting. Using a jammer is a criminal offence as well as a breach of most driver agreements.

Want to check your fleet would actually tell you if a tracker went quiet? Talk to Traknova.