Thieves know a modern car often carries a tracker, and some carry a device that tries to silence it. If you have fitted a tracker, or are thinking about one, the fair question is whether a jammer makes it pointless.
The honest answer: a jammer can stop a tracker from sending its position while the jammer is switched on and close by. It cannot erase the tracker, and a good setup is designed around that limit. This guide explains how jamming works at a basic level, what it does and does not achieve, what the law says in the UK, and what to look for in a tracker so a jammer is not a free pass.
What is a tracker jammer?
A jammer is a device that transmits radio noise on the same frequencies a receiver is trying to listen to. The receiver cannot pick out the real signal from the noise, so it effectively goes deaf. A car tracker relies on two kinds of signal, which means there are two things a thief might try to block:
- GPS (more accurately GNSS) jamming drowns out the weak signals from navigation satellites. The tracker can no longer work out where it is.
- GSM or mobile jamming blocks the mobile network. The tracker may still know where it is, but it cannot send that position to you.
Either way the owner sees the same thing: the live map stops updating. A jammer does not break a tracker or switch it off. It only tries to stop it being heard while it runs nearby.
Why do thieves use jammers?
There are two common reasons, and they are different problems.
To hide a stolen car. A thief who has taken the car, by whatever method, may carry a jammer to stop a tracker reporting the route. This is the case people usually mean when they search for this topic.
To stop the car locking. A different type of jammer blocks the signal from your key fob, so the car never receives the lock command. We cover that in our guide to keyless car theft and relay attacks. Always check the car has actually locked.
What can a jammer actually do to a tracker?
It helps to be precise, because there is a lot of exaggeration online in both directions.
What jamming can do:
- Stop a tracker from receiving GPS, so it cannot calculate a fresh position.
- Stop a tracker from sending data over the mobile network, so you do not see live updates.
What jamming cannot do:
- Work beyond its short range, or once it is switched off or its battery runs down. It only affects the car while it is on and nearby.
- Undo what the tracker has already sent. The route reported up to the moment the jamming started has already left the car, which gives you and the police somewhere to begin.
- Stop a tracker that is built to notice it. A jammer is a source of abnormal interference, and a tracker can be designed to detect GPS and GSM jamming and raise an alert as soon as it starts.
- Cancel the other protections on the car. Motion sensing, tamper alerts and an engine block do not depend on the thief leaving the signal alone.
The key idea: a tracker is one layer, and a jammer targets only that layer.
Is a GPS jammer illegal in the UK?
Using one is a criminal offence. The UK government says that using a jammer is a criminal offence, with narrow exceptions such as certain Crown and defence uses, and that Ofcom does not authorise jammer use for ordinary people or businesses. Making jamming equipment available on the UK market is also an offence where it does not meet the legal requirements.
The rules have tightened further for vehicle crime. The Crime and Policing Act 2026, which received Royal Assent in April 2026, creates two new offences covering the possession, import, making, adapting and supply of electronic devices used to steal vehicles or steal from them. The government gives a signal jammer as an example. The maximum penalty is five years' imprisonment, an unlimited fine, or both.
For the detail, read the government's Crime and Policing Act 2026 serious crime factsheet and its page on radiofrequency jammers and the legal framework.
What to look for in a jam-resistant setup
No consumer tracker can transmit through a jammer that is blocking its mobile connection. The better question is "what happens when it is jammed?" Look for:
- Jamming detection for both GPS and GSM. Not all trackers cover both. Ask for it by name.
- An alert when jamming starts, and another when it stops. The start tells you to act. The stop tells you the signal is back and the car may be moving again.
- Several alert channels. A push notification is easy to miss at 3am. A voice call is not.
- A motion sensor that works with the ignition off. If the car is lifted or towed, you want to know even when the engine never ran.
- Tamper and power-cut alerts, with a backup battery. Disconnecting the car battery is the oldest way to kill a tracker. A backup battery keeps the device running, and the alert tells you someone is interfering with it.
- Concealed, professional installation. A tracker that is hard to find is hard to remove.
- A second layer that does not rely on a signal. An immobiliser or engine block stops the car being driven away in the first place, so the jammer never gets used.
How Rubikas handles jamming
We are open about the limits, so here is what the Rubikas car tracker does and does not do.
It detects GPS and GSM jamming and tells you. The device detects both kinds of jamming and alerts you when it starts and when it stops. Alerts for tow, tamper, power cut and jamming reach you by push notification, email and voice call.
It does not pretend to see through a jammer. While a jammer is blocking the signal, the tracker cannot report a live position. What you do have is the alert itself, the route reported up to that moment, and the other protections below.
Other layers keep working. A built-in 6-axis motion sensor recognises when the car is lifted or towed, even with the ignition off. If the device is tampered with or its power is cut, you are alerted, and a built-in 250 mAh backup battery keeps it running.
Engine block and fingerprint ID. With the remote engine block, the block engages when the ignition is switched off, so a parked car cannot be started. With the fingerprint reader fitted, someone without a registered fingerprint cannot simply start the car with a key. We do not claim the block stops a car that is already moving. Our car immobiliser page explains how the two modules work together.
If a jamming alert reaches you, call 999 if a theft is in progress, or 101 otherwise, and give the police the registration and the last location you saw. Do not follow the car yourself.
Rental prices (24-month term, per car, including VAT): Rubi Track tracker £12.99 a month, Rubi Protect tracker plus engine block £16.99, Rubi Secure with fingerprint reader £21.99. See the car tracker page for the specification, or vehicle tracking if you manage more than one vehicle.
Frequently asked questions
Can car trackers be jammed?
Yes, for as long as a jammer is switched on near the car, it can stop a tracker receiving GPS or sending data. It does not destroy the tracker, and a tracker that detects jamming will alert you when it starts. Combining a tracker with an immobiliser covers the gap.
Do GPS jammers work?
Only in a narrow sense: they disrupt signals within a short range while powered on. They do not make a tracker disappear, and they do not affect protections that need no signal, such as an engine block.
Can GPS trackers be detected by thieves?
A poorly hidden device can be found. That is why professional, concealed installation and tamper alerts matter.
Are GPS jammers illegal in the UK?
Using a jammer is a criminal offence. Since the Crime and Policing Act 2026, possessing or supplying an electronic device for vehicle theft, such as a signal jammer, is also an offence, with a maximum penalty of five years' imprisonment, an unlimited fine, or both.
Will a tracker alert me if someone jams it?
Not every tracker does. The Rubikas car tracker detects GPS and GSM jamming and alerts you when it starts and stops, by push notification, email and voice call.
Want a tracker that tells you when someone interferes with it? Build your Rubikas bundle or call +44 7444 619588.