Car clocking - what is it and how to avoid buying a clocked car

Many people assume that the unscrupulous practice of clocking is dead. Yet the number of cars that have had their mileage altered has risen by 25% in the past three years. We find out why...

Car clocking - what is it and how to avoid buying a clocked car

Think of clocking and you’ll probably conjure up a not-so-nostalgic image of a man in oily overalls in a backstreet garage manually winding back a chunky 1990s car odometer with a screwdriver.

You’ll also be forgiven for thinking that the practice of turning back the clock on a car died with the demise of the analogue odometer. However, far from being the modern, secure solution to this shady practice, digital odometers have made it easier than ever for a car’s apparent mileage to be altered.

Car clocking - how much of a problem is it?

According to vehicle history check provider Car Vertical, 5.7% of the cars checked in the first few months of 2023 were found to be clocked, which could amount to 400,000 being put at risk of buying a car that's covered more miles than it first appears.

Another history check provider, Cap HPI recently said it estimated the potential cost to motorists at more than £800 million every year, because the value of an average second-hand family car will increase by £2000-£4000 if 60,000 miles are wiped off its odometer.

There’s also concern from both the car industry and those concerned with consumer rights. The National Franchised Dealer Association (NFDA) and the Chartered Trading Standards Institute (CTSI) both recently wrote open letters to the Government urging it to take action to address the rising tide of clocking after what they describe as many years of inaction.

How does mileage affect value?

The traditional reason for a dodgy dealer to clock a car was to get a higher price for it on the second-hand market. The temptation to clock a car is clear: a 2015 Ford Focus 1.0 Ecoboost that has done 50,000 miles could fetch around £2700 more on a used car forecourt than the same car with 100,000 miles. Below we look at how mileage affects the value of some popular three-year-old models.

Model with 30,00 miles with 60,00 miles with 90,00 miles
Audi A4 3.0 TDI quattro SE £18,150 £15,995 £14,100
BMW 520d SE £16,850 £14,750 £13,200
Mazda MX-5 2.0 Sport Tech Nav £13,600 £11,195 £9625
Seat Leon 1.2 TSI SE 5dr £8425 £7375 £6525
Skoda Fabia 1.2 TSI 90 SE £6150 £5195 £4575
Volkswagen Tiguan 2.0 TSI Tech SE £15,200 £13,250 £11,650

Why is clocking on the increase?

There are still instances of second-hand traders clocking cars on a massive scale. In June 2017, a man from Bedford was jailed for 32 months after making £190,000 from selling clocked cars. However, many in the industry believe it’s car owners rather than traders who are pushing the current increase in clocking.

“There are many factors that could be driving a rise in clocking,” says Barry Shorto, head of industry relations at Cap HPI. “One issue is the popularity of personal contract purchase (PCP) and personal contract hire (PCH) finance deals that often come with strict mileage limits, where each additional mile can prove costly. This has led some to turn to ‘mileage correction’ firms that offer to dial back the odometer to dodge the financial penalties.”

These days, most new cars are bought using PCP deals, which require the buyer to state how many miles they’ll cover in the car during the term of the contract. A car’s mileage has a big effect on its value, so there’s a penalty fee of an average of 10p for every mile that exceeds the agreed limit. So, if you say you’re going to do only 5000 miles per year on a three-year deal but end up racking up twice that much, you’re likely to be hit with a fee of £1500.

The NFDA also cites the lack of official recording of a car’s mileage for the first three years of its life as a contributory factor.

“Cars may need servicing each year, with the car’s mileage recorded in the service book, but a consumer can easily get a car clocked before it goes to the garage,” explains Louise Wallis, the NFDA’s head of business management.

Car clocking - what is it and how to avoid buying a clocked car

How are cars clocked?

Although it’s illegal to alter a car’s odometer and then sell it on without telling the buyer that its mileage has been changed, the actual act of turning back the odometer isn’t illegal.

And it’s easy to alter a car’s mileage nowadays, as the CTSI’s Gerald Taylor explains: “All new vehicles have digital systems – usually under the driver’s seat or in the engine bay – and it is simple to connect a laptop up to them and use software to alter the mileage.”

You don’t have to buy the software, either; search online and you’ll find a number of companies that will come to you and change your car’s mileage for a fee of around £100.

The CTSI has been campaigning for years to have these companies and the act of altering a vehicle’s mileage outlawed. The RAC agrees that the current situation isn’t acceptable. Williams says: “It’s absolutely ludicrous that shady operators are able to advertise their services, putting motorists at risk of buying a car with a tampered mileage, disguising its true history and likely level of wear and tear.”

Could a clocked car be dangerous?

As well as the potential to be left hundreds of pounds out of pocket if you buy a clocked car, consumers are being put in danger.

“A vehicle’s ongoing safety will correlate to its mileage,” says the CTSI, “so clocking can present a significant injury risk to consumers.”

For example, if you buy a car thinking it has covered just 5000 miles, you won’t expect major wear and tear items, such as tyres or brake components, to be nearing the end of their lives. However, if that car has actually covered 20,000 miles, these items might be worn out and could contribute to your car being involved in an accident.

There’s also a concern about major components failing because they’ve not been replaced at the right time. One prime example is a car’s timing belt: if this isn’t replaced at the correct mileage, it could break, resulting in hugely expensive engine failure.

How to spot a clocked car

1. Check its service history

The seller of a cared-for car will have plenty of past MOT test documents and a service book with stamps at all the right intervals to show you. Check that there are no gaps in the service history or any years where the mileage doesn’t go up. Also make sure that it goes up at a steady rate each year; alarm bells should ring if it’s been doing 20,000 miles a year for three years and then only 1000 the next one.

You can also check previous MOTs online at If you’re unsure about the stamps in a car’s service book, you can call the garages that are recorded as having carried out the service to verify that they actually did. If a car doesn’t have MOT and service history you can check in any way, don’t buy it.

Car clocking - how to spot a clocked car

2. Inspect its condition

Modern cars are generally well built and pretty durable, but you should still be able to spot a car that has covered a big mileage. On the exterior, look for stone chips on the bonnet – an indicator of a high motorway mileage – and make sure there are no different shades of colour on any body panels or doors, because this could indicate repaired crash damage. Inside, a saggy or worn driver’s seat spells high miles, as do worn pedals, switches and steering wheels.

3. Take it for a test drive

Try to get behind the wheel of two or three examples of the model you’re thinking of buying so you can get an idea of how it should feel to drive. A clocked car could have a sloppy gearbox, worn brakes and clutch and tired suspension. So, during your drive, listen out for clonks from the engine and other components that will give away the truth about a car’s mileage.

4. Ask questions

If there are discrepancies between a car’s mileage and its service history or condition, don’t be afraid to ask why. If you’re buying from a dealer, make sure there isn’t a disclaimer in the car’s advert or paperwork that states the mileage isn’t verified.

Car clocking - how to spot a clocked car

5. Get a history check

A history check can’t guarantee to tell you whether a car has been clocked – for instance, if it’s been done by the owner of a car less than three years old – but it will provide you with all the recorded mileages there are for the car, giving you a fair amount of reassurance. It will also alert you to other issues, such as if a car has outstanding finance on it or if it has previously been stolen or written off. Be wary of free or very cheap online car history checks, because they’re unlikely to be as comprehensive as those offered by the bigger players in this market. Opt for a Cap HPI check and the car’s mileage is checked against its National Mileage Register, which is the UK’s largest vehicle mileage database, with details of more than 220 million mileage readings as well as all those on the Government’s MOT database.

6. Keep checking the odometer

It has been known for unscrupulous car sellers to turn back a car’s mileage so that it looks impressive when you first see it. Then, if you decide to buy it, they’ll put it back up to the original mileage when you collect it so that they can’t be prosecuted for selling you a clocked car.

What Car? says…

Many in the car industry believe that the Government should make it illegal for anyone other than franchised dealers to be allowed to alter a car’s odometer, and even then it should only be done in certain restricted circumstances, such as when the odometer has broken and needs to be replaced.

What Car agrees that the Government should do something to stop the scourge of car clocking. At present, consumers face the possibility of ending up thousands of pounds out of pocket if they unknowingly buy a clocked car. Worse still, they could be put at risk of being involved in a car accident if they’re driving a car that has covered more miles than they realise.

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