How to Stop Keyless Car Theft: The Complete UK Guide

Keyless car theft has become one of the most common ways cars are stolen in the UK – and the frustrating part is that thieves never even touch your keys. The good news: a few simple, inexpensive steps stop it dead. This guide explains exactly how keyless (relay) theft works and the most effective ways to protect your car.

What is keyless car theft (relay theft)?

If your car unlocks automatically when you walk up to it with the key in your pocket, it has keyless entry – and that convenience is exactly what thieves exploit. Your key fob constantly broadcasts a short-range radio signal. In a relay attack, two thieves work together:

1. One stands near your house – by the front door, a window, or the wall nearest where your keys are kept – with a relay device that picks up your fob’s signal.
2. That signal is amplified and relayed to a second device held against your car door.
3. The car believes the genuine key is present, unlocks, and lets them start the engine and drive away.

It’s silent, takes under a minute, and leaves no damage – no smashed window, no forced lock. Many owners only realise when the car is already gone.

Which cars are at risk?

Any car with keyless entry, keyless go or a smart key can be targeted – it is not limited to premium brands. If you don’t have to press a button on the fob to unlock or start the car, it’s vulnerable. Cars with a traditional remote (where you physically press a button to unlock) are generally not affected by relay attacks.

How to protect your car from keyless theft

You don’t need to do all of these – even one good barrier makes your car a far less attractive target. Layering two or three is ideal.

1. Keep your keys in a Faraday pouch (the simplest fix)

A car key Faraday bag (also called a signal-blocking pouch) forms a shield around your fob so its signal cannot escape to be captured or amplified. Drop your keys in when you get home and the relay attack simply has nothing to grab. It’s the cheapest and easiest protection – and it travels with you to hotels, the gym or festivals. Remember to protect every fob for the car, including spares, because thieves only need one.

2. Check if your fob can be switched off

Some manufacturers let you disable the fob’s wireless signal when it’s not in use – often a double-press of the lock button, or a setting in the car’s menu. Check your handbook; if yours supports it, it’s a free extra layer.

3. Store keys away from doors and windows

The relay device has to get close to your fob. Keeping keys toward the centre of your home, away from the front door, letterbox and windows, makes the attack much harder. Never leave them on the hallway table by the door.

4. Use a visible deterrent

A steering wheel lock or wheel clamp is old-school but effective. It won’t stop the car being unlocked, but it stops it being driven away – and the moment a thief sees one, they usually move on to an easier target.

5. Lock your OBD port

Some thieves plug a device into the car’s diagnostic (OBD) port to program a blank key. An OBD port lock blocks this method.

6. Physical barriers and a tracker

A driveway post, bollard, or simply parking a second car behind the keyless one buys time. A GPS tracker won’t prevent theft, but it greatly improves the odds of getting your car back.

How to test your Faraday bag actually works

It takes ten seconds: put your fob fully inside, seal it, then walk up to your car and try the door handle, or stand right next to it and press to start. If the car doesn’t respond, the bag is blocking the signal. (Just remember to take the fob back out before you drive off!)

Frequently asked questions

Do Faraday bags actually stop keyless car theft?
Yes. With the fob sealed inside, its signal cannot escape to be captured or amplified, which blocks the relay attack used to steal keyless cars.

Do I need to protect both car keys?
Yes – thieves only need to relay one fob, so keep every key for the car protected, spares included.

Will my key fob still work after being in a Faraday bag?
Absolutely. The bag only blocks the signal while the fob is sealed inside. Take it out and it works exactly as normal.

Which cars are affected by keyless theft?
Any car with keyless entry or keyless start. If you don’t press a button on the fob to unlock the car, it can be targeted.

Is keyless car theft really that common in the UK?
Yes – it is now one of the most common methods of vehicle theft, which is why blocking your fob’s signal is worth doing.

Protect your car in seconds. Browse our car key Faraday bags – signal-blocking pouches that stop relay theft, in stock and ready to ship across the UK.