This blog explains why checking a vehicle’s mileage history before you buy is a must in the UK. Our FAQ below runs through all you need to know about mileage adjustment.
Total Car Check now provides an enhanced MOT mileage check in all Silver and Gold checks. This returns records of any motor industry mileage readings recorded before a vehicle has had its first MOT. For more information and to run a check visit our mileage check page.
What is vehicle mileage adjustment?
It’s where someone uses equipment to change a vehicle’s mileage reading. Reducing the vehicle’s mileage helps to boost its value, because it gives the impression to buyers that the vehicle has been used less. Reducing a vehicle’s mileage is often referred to as ‘clocking’. This is because the odometer (mileage gauge) was traditionally linked to the speedometer, which has dials like a clock as below.

Is vehicle mileage adjustment legal?
Unfortunately the stand alone practice of adjusting a vehicle’s mileage is legal. If you ran a search online you would find many garages across the UK that offer mileage adjustment services. DIY mileage adjustment equipment can also be obtained online cheaply.
But selling or misrepresenting the vehicle as having lower mileage is illegal. Selling a clocked vehicle is illegal under consumer law and can also be prosecuted against under a criminal fraud offence.
Are there legitimate reasons to adjust a vehicle’s mileage?
Yes, but these are very uncommon. Where vehicles are restored to the point a new engine and other parts have been introduced then it is within reason to adjust the odometer. In any case the person adjusting the mileage must disclose how much the mileage has been reduced by when selling.
Haven’t manufacturers developed technology to prevent clocking?
Yes they have, but like with any crime there is a technology battle. Most modern vehicles record mileage in a vehicle’s onboard computer. So the problem has become a software related one. Once the manufacturer develops a defence hackers write new software to break through these defences and they embed it into adjustment hardware.
What are the risks of buying a clocked vehicle?
If you buy a vehicle that’s had its mileage wound back then you will almost certainly lose out financially. The vehicle will be worth less than what you paid for it. Running it will lead to a higher risk of parts needing replacing. In extreme cases the vehicle could also be unsafe to drive – particularly where critical parts don’t work properly such as the engine, brakes, clutch etc.
Who clocks vehicles?
Because clocking equipment is so easy to obtain in the UK lots of different types of people are adjusting mileage. Here are three common scenarios. But be under no illusion. These sorts of practices have led to prison sentences and hefty fines for those that have been caught.

The individual who wants to limit the amount they owe to lenders
Clocking has been incentivised in recent years because of the rise of Personal Contract Purchase (PCP) and Personal Contract Hire (PCH) finance and lease agreements. They now fund over 80% of new vehicles sold in the UK.
PCP and PCH build in a mileage allowance. The higher the mileage allowance the higher the monthly payment you pay to the lender/lessor. Also if the mileage allowance is exceeded in any one year then additional mileage charges are payable. This type of offender is a person that may be in financial distress and feels like clocking could be a way out of charges they owe to lenders.
The petty criminal that buys cars, clocks them and sells them on
Taking clocking a step further is the petty criminal that wants to profit from this practice. They may work with others to help them sell their vehicles, but if not will be selling vehicles privately and advertising them online. Typically selling using online platforms and social media such as eBay, Gumtree and Facebook Marketplace.
The organised criminals that clock vehicles at scale
There are intelligent organised crime gangs that go to great lengths to disguise their clocking activities. They may use online channels to sell. There has also been instances of criminals setting up legitimate businesses to market their vehicles, such as a dealership. Organised clockers will also likely be involved in other more serious organised crime. Clocking could be their sole focus or could be one ‘division’ of their illegitimate business activities.
How can I protect myself from buying a clocked vehicle?
- Carry out a Total Car Check Gold check on our website or on our app available on the app stores.
- Even if our vehicle check report show’s the vehicle holds no mileage issues, go and view and inspect it. Have a look at the bodywork, interior and under the bonnet and check the VIN.
- Take it out for a test drive to see how it runs.
- If you need further reassurance purchase a vehicle inspection service making sure that the inspector is an IMI accredited vehicle inspection technician.
Take a look at our used vehicle buyer advice for further tips about buying vehicles.
What is Government doing to stamp out clocking?
Up until now, the Government, law and authorities have done very little to stop vehicles being clocked. After all it remains legal to adjust a vehicle’s mileage.
The motor industry has for many years called for Government to introduce new laws to tackle clocking in order to protect motorists.
In 2021 the Government consulted on introducing what could be wide ranging new offences for ‘tampering’ with a vehicle. Although the proposals don’t specify mileage adjustment, clocking is tampering and would therefore be included as a tampering offence. However, the motor sport industry has signed a petition against these proposals, in fear that their constant renewal, and rebuilding of vehicles would be deemed illegal.
MOT is important for recording mileage
The Government has also proposed changes to MOT testing which is the main way in which mileage is recorded. The data is managed by the Driver and Vehicles Standards Agency (DVSA). Government recognises that increasing the period from new to first MOT and between MOTs (as proposed) provides more opportunity for criminals to clock vehicles. It is therefore asking for ideas about how to prevent mileage fraud.
The MOT consultation references the Government’s Future of Transport Regulatory Review, which includes the above tampering proposals. The impact of Brexit, Covid and recent political leadership issues has meant all of the above work remains on the drawing board. Expect little change to the law in the short to medium term.
Does industry data show that clocking is getting worse?
Yes it does. HPI has been tracking mileage discrepancies shown by its data for many years. In 2016 HPI said that 1 in 20 of vehicles had been potentially clocked, whereas in 2020 this has increased to 1 in 11 vehicles having a mileage discrepancy.
Total Car Check undertook analysis in 2020 which showed that over 3 million, or 1 in 18 UK vehicles, had their mileage reduced. With the average mileage reduction of over 46,000 miles.

The review we undertook showed that a number of mileage discrepancy issues were due to garages entering typos in their MOT systems. We have repeatedly called on the DVSA to put in place warnings to garages where they may have made a data entry error. This would lead to the MOT certificate displaying the wrong mileage. We are pleased to see that the DVSA has now listened to Total Car Check and others. It is now putting in place a solution to help stop garages submitting incorrect mileage readings.