The short answer: keyless car theft, often called a relay attack, is when thieves use electronic devices to pick up and boost the signal from your key fob, so the car behaves as if the key is right next to it. The car unlocks and starts, often quickly and quietly. You can cut the risk by blocking your fob's signal, adding a visible physical deterrent and checking your car's key settings. Because no single step stops every theft, it also pays to have protection that can help get the car back if it's taken anyway.
Keyless entry is convenient: walk up, open the door, press start. The same convenience can be used against you. This guide explains how keyless theft works, how common it is, what the law says and how to make your car a harder target.
How a relay attack works
- One thief stands near your home with a device that searches for your key fob's signal, often through a front door or window.
- That device boosts the signal and passes it to a second device held by an accomplice standing next to your car.
- The car detects what it takes to be its own key, unlocks and lets the engine start.
- Cars are generally designed not to cut out on the move, so once it's driven away the thieves can take it somewhere quiet.
Relay is not the only electronic method. Thatcham Research also names signal jammers, emulators that copy the function of a key, and devices that inject false signals into the car's internal network (known as CAN injection). Some of these don't need your key's signal at all.
How common is keyless theft?
- Signal manipulation is widespread: according to the Home Office, the Crime Survey for England and Wales found that manipulating the signal from a remote locking device was used in 36% of vehicle thefts between April 2019 and March 2020. The Metropolitan Police estimates that electronic devices are used in around 60% of vehicle thefts in London.
- Most stolen vehicles are taken without keys: recovery specialist Tracker reported in November 2025 that 93% of the vehicles it recovered had been taken without the keys.
- Owners are being targeted: in an October 2026 MoneySuperMarket survey of 500 keyless car drivers, 14% said they had been a victim of relay theft or attempted relay theft. Yet only 22% used a Faraday pouch or signal-blocking box.
- Popular models are hit hardest: DVLA figures analysed by MoneySuperMarket show the BMW 3 Series was the most stolen keyless entry model between 2023 and 2025, with 4,223 thefts.
What the law now says
The Crime and Policing Act 2026 sets out new offences of possessing, importing, making, adapting, supplying or offering to supply an electronic device for use in vehicle theft. The maximum penalty is five years in prison, an unlimited fine or both. Thatcham Research says the change lets police seize these devices without having to link them to a completed theft.
That's a welcome step, but it won't stop every theft. The practical steps below still matter.
How to protect a keyless car
- Block the signal: keep every fob, including spares, in a Faraday pouch or signal-blocking box. Test it now and then by trying to open the car with the fob inside, and replace it if it fails.
- Keep keys away from doors and windows: the further the fob is from the outside of your home, the harder it is to reach.
- Check your fob and car settings: ask your dealer whether your fob has a motion sensor that makes it sleep when it's not moving, and check your handbook for any option to turn keyless entry off.
- Add a visible deterrent: a steering wheel lock adds time and effort, which can put opportunist thieves off.
- Park thoughtfully: on a drive where you can, in a well-lit spot, and within view of a camera.
- Buying a new car? Thatcham Research suggests looking for Ultra-Wide Band (UWB) technology, available on some modern vehicles and designed to resist relay attacks.
- Plan for the worst: hidden protection with a response behind it gives you a route to getting the car back if everything else fails.
How HoldenTek helps if a keyless car is taken
HoldenTek is a UK vehicle and asset security company, not simply a tracking company. Our covert tag is wireless and battery powered, so it isn't wired into the car's electrics. It's IP67 waterproof, the size of a credit card and lasts up to 2.5 years on its battery, and you hide it yourself with no installation visit. It's Built to Stay Hidden: it isn't picked up by everyday phone and Bluetooth scans like AirTags are.
If your car is taken, you hold one button in the app and call HQ, 24/7. Once the theft is confirmed, our security personnel work to locate and secure it through Project TAKEN, our security response capability. There are more than 580 of them, predominantly ex-police, military and close protection, positioned across the UK, excluding Northern Ireland. If the car is recovered with no damage, you can collect it without involving your insurer.
Our track record to date is a 100% success rate, with an average hunt and secure of 46 minutes. These are historical figures, not a guarantee for any individual vehicle. See car protection and how a recovery works.
Questions people ask
Do Faraday pouches actually work?
A good one blocks your fob's signal, but pouches can wear out with daily use. Test yours regularly with the fob sealed inside.
Can a keyless car be stolen without the key's signal?
Yes. Some methods, such as CAN injection, work through the car's own internal network rather than the key. That's why layered protection matters more than any single gadget.
Sources
- GOV.UK: Crime and Policing Act 2026, serious crime factsheet (Home Office)
- Thatcham Research: Crime and Policing Act 2026 strengthens UK vehicle security
- Tracker: Legislation must be enforced as keyless thefts soar
- Insurance Edge: Keyless entry theft attempts remain a threat (MoneySuperMarket survey and DVLA FOI data)
HoldenTek track-record figures are our results to date and are not a guarantee for any individual vehicle. This guide is general information, not legal or insurance advice.