Best Car Key Signal Blockers 2020 UK


Every 1 minute, a car is stolen in the United Kingdom, which is close to a million vehicles per year. Thieves are now more sophisticated than ever, opening and operating your car without needing to break in. Using “signal amplification” to gain unauthorized access to your car, these thieves can steal your car with total ease. So these Car Key Signal Blockers can protect your car, putting your car keyless fob into one of our special Keyless entry fob signal blockers, preventing your keyless entry fobs from being remotely accessed.

The convenience of Keyless entry fob signal blockers has made entering and leaving our cars so much easier. The physical key can be kept on your person and is no longer something you have to struggle to dig out when your hands are carrying other things. Simply walk up to the car, open the door and press the button to start the engine, doing the reverse when you leave the car.

Thieves are tech-savvy and can use relay attack devices to obtain the correct frequency from your key. Using this copied frequency makes driving away in your car a simple task, with no smashed glass, bypassing of car alarms or complex ignition systems to worry about.

• How to avoid keyless entry car theft

A Car Key Signal Blocker bag eliminates this concern. Lined with a layer of metal, it blocks the devices that thieves use to get the frequency from your key. These bags can also work with mobile phones and credit cards, keeping your mind at ease.

There are a number of these bags on the market and we’ve tested three of them to find out which is the best one to buy.

How Car Key Signal Blocker bags were tested

In the first test, we tried to open the car door with the car’s key in the bag next to the driver’s door handle. Next, we pressed buttons on the key fob within the bag. Finally, with the key still bagged up in the cabin, we pressed the engine start button.

We also assessed the build quality, cost and usability of the bags. An app was used to check the phone, Bluetooth and Wi-Fi signal-blocking capabilities.


The results were very close because all the products worked as the manufacturers stated. With this in mind, we turned to the quality, practicality and value for money offered by each of the products.. The best signal blocker was the Defender, a bag that’s big enough to accommodate other items too. Both the Disklabs KS1 and the Ecence weren’t far behind.

1. Defender Signal Blocker

2. Disklabs Key Shield Faraday Bag KS1

3. Ecence RFID Radiation Protection Bag


Defender Signal Blocker

Price: Around £5

Size (cm): 18.5 x 11.5

Rating: 5.0

Our winner successfully blocked all signals and had excellent build quality. Surprisingly, it’s the cheapest to buy too. It’s the second largest bag out of the ones tested, easily handling larger phones, but it could be a bit excessive if you only have a small set of keys. We were happy to accept its size given the benefits the Defender gives you for the price.

Disklabs Key Shield Faraday Bag KS1


Price: Around £17

Size (cm): 12 x 10

Rating: 4.5

The Disklabs bag instantly inspired confidence, as it was the only one here given the ‘Secured by Design’ accreditation from the police. The build quality was among the best here and the effectiveness of the signal blocking worked even with the flap still open. It would fit most keys nicely. It’s a pricey choice, but it feels like a sound investment.

Ecence RFID Radiation Protection Bag

Price: Around £7

Size (cm): 12.5 x 8

Rating: 4.5

Designed for key use only, the Ecence bag is exactly the same as the Halfords and B-G, aside from the fact it’s cheaper, hence why we rated this one higher. It performed signal blocking well, the material itself thick and reassuring. The only quibble we had was the lack of stitching quality, especially at the bottom of the bag and whether this had the potential to wear with use.

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