How to Stop Relay Attacks

Your Ultimate Guide to Car Theft Prevention

Your keyless entry car is a prime target for thieves. The threat is real: criminals can capture and relay your key’s signal from inside your home, stealing your vehicle in under 60 seconds. This vulnerability creates constant anxiety and leaves you questioning which security measures actually work. The solution is not to live in fear. The solution is to understand how to stop relay attack car theft with proven, effective technology. This guide provides the definitive answer to permanently securing your vehicle.

Forget the guesswork and temporary fixes. We cut through the noise to compare every available security option. Discover the limitations of basic Faraday pouches and why professional systems like the Ghost Immobiliser offer unparalleled protection. We will provide clear, expert analysis on the best methods to safeguard your investment, giving you the confidence that your car is safe and sound on your drive. Secure your peace of mind today.

Table of Contents

• What Is a Relay Attack and How Does It Work?

• Layer 1: Essential First Steps (Low-Cost & DIY Methods)

• Layer 2: Physical & Visual Deterrents

• Layer 3: The Ultimate Fix – Advanced Electronic Security

• What’s the Right Level of Protection for You?

What Is a Relay Attack and How Does It Work?

Keyless entry systems offer modern convenience but have introduced a critical security flaw. Criminals now exploit this technology using a method called a relay attack, a silent and effective way to steal your vehicle without ever touching your keys. Understanding this threat is the first step toward stopping relay-attack** car theft** and securing your property.

A relay attack is a two-person job. One thief stands near your home or office, holding a relay device designed to detect and amplify the signal from your key fob, even through walls, doors, and windows. This captured signal is then transmitted to a second device held by an accomplice standing next to your car. The car is tricked into thinking the key is right beside it, allowing the doors to be unlocked and the engine started. The entire process is silent and can take less than 60 seconds.

The scale of this problem is significant. Industry reports indicate that 92% of stolen vehicles recovered in one year were stolen without the owner’s keys, with relay theft being a primary method for this alarming statistic.

The Simple Science Behind the Theft

Think of the technique as giving your keyfobs’ signal a much louder ‘voice’. The first relay box acts as a powerful listener, capturing the unique radio frequency signal that your key constantly emits. This sophisticated method, technically known as a Relay attack, bypasses standard security by simply extending the key’s operational range. The second box receives this signal and ‘re-broadcasts’ it next to the car’s door, fooling the vehicle’s computer into granting access. Thieves gain full control of your car without force, damage, or the original key.

Which Cars Are Most at Risk?

Any vehicle with a keyless entry or keyless start system is potentially vulnerable. While organised criminals often target high-value SUVs and performance cars from brands like Range Rover, BMW, and Audi for their high resale value, any car with this technology can be stolen. Some manufacturers have introduced fobs with motion sensors that enter a ‘sleep’ mode when left still, but this is not a universal solution and does not protect millions of older vehicles. Relying on factory-fitted security alone is no longer sufficient to stop determined thieves.

Layer 1: Essential First Steps (Low-Cost & DIY Methods)

Before investing in advanced security systems, implementing basic keyfob discipline is the absolute minimum level of protection. These methods are designed to make your vehicle a less convenient target for opportunistic criminals. For owners asking how to stop relay attack car theft, the answer begins with these foundational habits. Their primary weakness is human error; they are only effective if you use them without fail, 100% of the time. Remember, this applies to all your keys, including the spare one tucked away in a drawer.

Using a Faraday Pouch or Signal-Blocking Box

A Faraday pouch, or a larger signal-blocking box for multiple keys, is a simple and affordable solution. These containers are lined with a special metallic fabric that creates a "Faraday cage," which physically blocks your key fob’s radio signal from escaping. Thieves cannot amplify a signal that isn’t there. We recommend you purchase a reputable pouch and test it regularly: place the key inside, walk up to your car, and see if the doors will open. If they do, the pouch is no longer working. The main drawback is the inconvenience of using it every single time, but it is a critical security habit.

Other ‘Home Brew’ Solutions

If you need an immediate, no-cost solution while you wait for a professional installation, there are several DIY options. While not as reliable as a purpose-built pouch, they still offer some protection.

• Metal Tins: A simple metal container, such as a biscuit tin or an old paint can with a secure lid, can serve as a makeshift signal blocker. Test it thoroughly before relying on it.

• Physical Distance: Do not leave keys on a hook by your front door. Storing them in the centre of your home, as far as possible from exterior walls and windows, can make it much harder for thieves to capture the signal from the street. This aligns with official police prevention advice on making your vehicle a harder target.

• Deactivate the Fob: Consult your vehicle’s manual. Some manufacturers offer a method to temporarily turn off the key’s wireless transmitter, which is a highly effective way to stop relay attacks at the source.

Layer 2: Physical & Visual Deterrents

While blocking your key’s signal is the first line of defence, a layered security strategy is the most effective approach to stopping relay-attack car theft. A successful relay attack only gets the thief inside your car and allows them to start the engine; they still need to drive it away. Understanding the sophisticated, electronic nature of how relay attacks on PKES systems work makes it clear why adding a crude, physical barrier is so effective. It introduces a noisy, time-consuming mechanical problem that criminals are not prepared to solve.

Thieves seek the path of least resistance. Your goal is to make your vehicle a difficult, high-risk target. These physical and visual deterrents achieve exactly that, forcing criminals to move on to an easier vehicle. While a determined thief with heavy-duty tools can eventually defeat them, they make the casual or opportunistic attacker think twice.

Steering Wheel Locks

The steering wheel lock is a classic, cost-effective, and highly visible security measure. Its presence immediately signals to a potential thief that your vehicle will require extra work, noise, and time to steal. For maximum protection and potential insurance benefits, we strongly recommend choosing a high-quality, Thatcham-approved lock made from hardened steel. These are rigorously tested to withstand common attack methods.

• Pros: A powerful visual deterrent that is simple to use and relatively inexpensive. It complicates the theft even after the engine has been started via a relay attack.

• Cons: Can be bulky to store when not in use and adds an extra step to every journey, which some drivers find inconvenient for daily use.

Driveway Posts and Wheel Clamps

For securing your vehicle at its most vulnerable location, your driveway overnight, these heavy-duty solutions offer an exceptional level of protection. A driveway security post is a retractable or removable steel bollard installed at the end of your driveway, creating a physical barrier that prevents the car from being driven away. Wheel clamps function similarly by immobilising a wheel, making the vehicle undrivable.

These are formidable visual deterrents. However, their primary drawback is a lack of portability. They are fixed solutions designed exclusively for home security and are not practical when you are parked at work, at the shops, or away from your property.

Layer 3: The Ultimate Fix – Advanced Electronic Security

While physical deterrents and signal-blocking pouches offer a first line of defence, they only delay a determined thief. To truly defeat a relay attack, you need an active electronic security system. These solutions integrate directly with your vehicle’s complex electronics, creating a digital fortress that actively prevents the car from being driven away. Unlike passive methods that slow thieves down, advanced systems provide a definitive stop.

Don’t settle for half-measures when your vehicle’s security is on the line. Explore our advanced security systems and get total peace of mind with professional, UK-wide installation.

Aftermarket Alarms and Immobilisers

A professionally fitted, Thatcham-approved alarm enhances your factory system with more sensitive sensors (such as tilt and glass-break) and a much louder, battery-powered siren. Paired with a traditional immobiliser that cuts power to the engine, this provides a solid security upgrade. However, sophisticated criminals with advanced tools can sometimes find ways to bypass these conventional systems.

Insurance Approved S5/S7 Trackers

It is crucial to understand that a tracker does not prevent theft; its purpose is to facilitate stolen vehicle recovery. Often required by insurance companies for high-value vehicles, S5 and S7 trackers use GPS technology to pinpoint your car’s location. Advanced S5 systems include features like Automatic Driver Recognition (ADR) tags. If the vehicle is moved without a tag, an alert is sent directly to a 24/7 monitoring centre, triggering recovery procedures.

The Gold Standard: The Ghost Immobiliser

For owners who ask how to stop relay-attack car theft for good, the Ghost Immobiliser is the definitive answer. This revolutionary device makes the relay attack completely useless. Even if thieves amplify your key’s signal and open the door, they will be unable to start the engine.

The Ghost integrates with your car’s CAN bus network and requires a unique, user-defined PIN code to be entered using existing buttons on your steering wheel or dashboard before the vehicle will start. Key features include:

• Completely Invisible: No physical unit to find, no flashing LED to give it away.

• No Key Fobs: Nothing to be cloned or stolen. The system uses the buttons you already have.

• Undetectable: Cannot be found with diagnostic or scanning tools used by thieves.

This technology is the ultimate safeguard, ensuring that even with possession of your keys, a thief is left powerless.

What’s the Right Level of Protection for You?

Choosing the right security is not a one-size-fits-all solution. The best defence against relay attacks involves layering different types of protection-Basic (signal blocking), Physical (visual deterrents), and Electronic (covert immobilisation)-to match your specific risk level. Before investing, take a moment to assess your situation.

Consider these critical factors:

• Vehicle Value: Is your car a desirable, high-value model frequently targeted by thieves?

• Insurance Requirements: Many insurers now mandate a Thatcham-approved tracker for premium vehicles to provide cover.

• Local Crime Rates: Do you park on the street in an area with a high vehicle theft rate?

Understanding your risk helps you choose a proportionate and effective solution. The table below offers a straightforward comparison of the most common security methods.

For the Budget-Conscious

For a solid, low-cost deterrent, combine a quality Faraday pouch with a highly visible steering wheel lock. This strategy’s success relies entirely on your diligence-you must use it every time you leave the car. While this pairing makes your vehicle a less appealing target, it is fundamentally a deterrent, not a guarantee of prevention.

For High-Value or High-Risk Vehicles

If you own a premium vehicle or live in a high-risk area, a multi-layered electronic defence is the only reliable answer. The ultimate solution for stopping relay-attack** car theft** is combining a Ghost Immobiliser to physically prevent the engine from starting with an S5 Tracker to meet insurance mandates and ensure rapid recovery. This is the package our experts fit most often for complete protection and peace of mind. View our security packages.

Your Ultimate Defence Against Relay Car Theft

Relay attacks pose a significant and growing threat to modern vehicles, but they are preventable. As we’ve covered, the key is a layered security approach. While low-cost solutions like Faraday pouches offer a basic first line of defence, true security comes from combining these with robust physical and electronic deterrents. Ultimately, knowing how to stop relay attack car theft means investing in professional, high-tech countermeasures that criminals cannot easily bypass, such as a Ghost Immobiliser or a Thatcham-approved tracker.

Don’t leave your vehicle’s security to chance. For the highest level of protection, professional installation is essential. At Safe & Sound Mobile, our Thatcham Approved Installers deliver 5-Star rated service directly to you with our Nationwide Mobile Fitting Service. We provide the industry-leading security systems that offer a definitive answer to keyless theft.

Ready to make your vehicle safe and sound? Secure your vehicle against relay theft. Speak to our experts today. Take decisive action and regain your peace of mind.

Frequently Asked Questions

Will my car insurance cover me if my car is stolen in a relay attack?

While most comprehensive policies should cover theft, insurers can be difficult to deal with if there’s no forced entry, which is common with relay attacks. You may face a difficult claims process and a higher premium upon renewal. Investing in a Thatcham-approved security system, such as a Ghost Immobiliser or a vehicle tracker, provides physical proof of protection, strengthening your claim and often lowering your insurance costs. It’s the only way to be certain you are protected.

Are car manufacturers doing anything to stop relay theft?

Some manufacturers are introducing newer key fobs with motion sensors that deactivate when idle, or using Ultra-Wideband (UWB) radio technology. However, this technology is not standard across all new models, and it offers no protection for millions of existing cars on UK roads. The only guaranteed way to secure your vehicle today is with a professionally installed aftermarket security system. Don’t wait for manufacturers to catch up; protect your asset now.

If I use a Faraday pouch, do I still need a Ghost Immobiliser?

A Faraday pouch is a good deterrent, but it relies entirely on correct and consistent use. These pouches can degrade over time, and a thief can still perform a relay attack if you forget to use them or if they target you when the key is out. A Ghost Immobiliser provides a separate, physical layer of security that works independently of your key. Even if thieves bypass your key’s signal, they cannot start the engine without your unique PIN code.

Do relay attacks work on electric and hybrid cars, too?

Yes. Any vehicle with a keyless entry and start system is vulnerable to a relay attack, regardless of its powertrain. Electric (EV) and hybrid cars are often high-value targets for thieves due to their advanced technology and resale value. The method used to steal them is identical. Securing your EV or hybrid with an immobiliser or tracker is a critical investment to protect against this modern theft technique. Your vehicle’s fuel type offers no protection.

Can just one person carry out a relay attack?

Typically, a relay attack requires two criminals. One stands near your home or office with a device to capture your key’s signal, while the second stands by your car with a transmitter. This ‘relays’ the signal, tricking the car into opening and starting. While a single person could theoretically attempt it with complex equipment, the two-person team method is overwhelmingly common due to its speed and efficiency. This organised approach is precisely why professional security is essential.

What about my spare key? Does it need protecting too?

Absolutely. Your spare key fob is identical to your main key and emits the same constant signal, making it equally vulnerable. Thieves don’t know which key is which; they only need to find a signal. You must protect both keys, preferably by storing them in separate Faraday pouches when not in use. This is a critical step in stopping relay-attack** car theft**, but for total peace of mind, an immobiliser protects your vehicle regardless of the key’s location.