Does storing your car keys in a microwave prevent theft?

South Wales Argus

03-06-2025

Usually, storing car keys in a kitchen may mean hanging them on a key holder or placing them in a dish.
But a recent increase of motorists storing their car keys in a microwave has led to experts to express their concern.
Yes, the trusty microwave has seen an increase in key storage overnight as it appears it's not only used for a quick re-heat of a midnight snack.
Why do people store car keys in the microwave?
Ofcom states that it's all down to the latest methods that crafty thieves are taking advantage of with keyless fobs.
'These keyless fobs use radio frequencies to communicate with your car, allowing it to unlock and start it when you have it in your possession,' Ofcom says.
'Sadly for car owners, thieves are sometimes able to use bits of tech that capture and amplify these frequencies in a way that helps them to gain access to your car.
'And if they can get near enough to the fob, for example by lurking close to your home or in your driveway, they can do this while it is inside your house – where you might think it's safe.'
Does putting car keys in the microwave block signal?
Because a microwave uses high-power radio waves to heat food, these can block the signal between your keys and car – but they're not the most ideal or safe solution.
We spoke to experts from car leasing deals site LeaseLoco, who have been hearing about a rise in this peculiar trend.
John Wilmot, CEO and founder of LeaseLoco, said: 'Thieves are becoming increasingly savvy when it comes to keyless car theft.
'Many modern cars use radio frequency signals to communicate with key fobs, which means criminals can use relay devices to capture and amplify these signals - even when the key is inside your home - to unlock and steal your vehicle.
'While it's true that microwaves are designed to block electromagnetic signals, using one as a storage place for your car keys is far from practical - and potentially dangerous.
'Microwaves are not a safe or recommended alternative to a proper signal-blocking solution.'
What happens if you accidentally microwave your car keys?
It's easily done – you're in a rush and accidentally catch the timer on your microwave, or worse still, microwave a ready meal with your keys already inside.
Mr Wilmot continued: 'If you forget the keys are inside and accidentally turn it on, you risk seriously damaging the fob's delicate electronics.
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'That could mean short circuits, melted components, or total failure, and repairs or replacements can run into the hundreds.
'Worse still, microwaving a key fob introduces a real fire hazard. The metal components inside could spark, potentially causing smoke, flames, or even damage to your microwave and home.
'The safer, more reliable option is a purpose-made RFID-blocking pouch or Faraday box. These are specifically designed to block key signals and protect your car from relay theft, without the risk of frying your keys!'