What is mileage clocking, and why does it happen?
A car's value drops as the miles climb. Knock the reading down and the asking price can rise by hundreds or thousands of pounds, which explains why people do it.
It happens anywhere in the chain. Sometimes a private seller, sometimes a back-street trader, sometimes someone further up who bought at auction and "corrected" the figure before selling it on.
The method has changed. Older cars had mechanical dials, wound back by hand. Modern cars store the mileage electronically. A tool plugged into the diagnostic port rewrites the figure held in the instrument cluster.
The effect is the same either way. The electronic version often leaves no visible sign on the dashboard. So you can't trust the clock itself. You'll need to check the paper and data trail behind it.
Is mileage clocking illegal?
Selling a car on a false mileage is against the law. But "clocking is illegal, full stop" is too blunt to be useful. The detail matters, because it changes what you can do about it.
What the actual offence is
The law targets misleading a buyer, not the private act of turning a number back. Under the rules that govern the motor trade, it is a criminal offence for a trader to mislead a buyer about a vehicle. Trade-standards guidance is explicit about what that covers: altering an odometer reading, and supplying or offering to supply a vehicle with a false mileage. It also covers putting a false mileage in an advert on or near the car.
Silence counts too: failing to disclose a mileage discrepancy the seller knows about can be a "misleading omission".
That offence applies to traders: anyone selling in the course of a business. A genuine private seller who lies about mileage isn't caught by this particular criminal regime. They can still be liable to you in civil law for misrepresentation. Honesty is the rule either way; what changes is who enforces it and how.
The current law — and why competitors get it wrong
Most guides still cite the Consumer Protection from Unfair Trading Regulations 2008. That regime was replaced. Since 6 April 2025, the law that applies is the Digital Markets, Competition and Consumers Act 2024. Its unfair-trading provisions sit in Part 4, Chapter 1, which set out the offences of misleading actions (section 226) and misleading omissions (section 227).
Trading Standards' own trade guidance now points squarely at this Act for mileage descriptions.
The same Act gave the Competition and Markets Authority (CMA) new powers to act directly against misleading practices. Those powers include issuing fines without going to court. Local Trading Standards teams still investigate and prosecute clocking on the ground.
These cases are real: in 2023, Royal Borough of Kensington and Chelsea Trading Standards prosecuted a trader who had clocked 46 cars. The genuine service history was destroyed and MOT certificates forged to match. The result was a two-year suspended prison sentence.
This is a general explanation, not legal advice. Any specific dispute can turn on its own facts. If you're unsure where you stand, check the current guidance on gov.uk or Citizens Advice.
How to check a car's mileage history before you buy
Compare the odometer against the MOT history (the best free check)
Do this one first. It costs nothing, and every time a car over three years old is MOT tested the tester records the mileage. GOV.UK's free MOT history service shows that figure at every test back to 2005, from just the registration.
You can run this check on our site. Our free car check pulls the full MOT history, including the mileage logged at each test. It shows the car's road-tax status alongside that, all from one number-plate lookup.
Cross-check the service history
The service book and any digital service records give you a second, independent mileage trail. The figure stamped at each service should match the MOT pattern and today's reading.
Patchy or missing service history isn't proof of clocking. It does remove one of your best cross-checks. A seller who can't produce it deserves more scepticism, not less.
What a paid check adds
Sometimes the MOT and service history are thin. A younger car has few tests behind it, and plenty of cars turn up with no service book at all. A paid history check then gives you more to go on.
Our Comprehensive check pulls the car's mileage record together with the things the free lookup can't show. That's outstanding finance, insurance write-off markers, stolen-vehicle flags, plate changes and previous keepers.
It won't reconstruct a mileage that was never recorded anywhere. What it does is widen the paper trail you're checking against. You can see exactly what one looks like in this sample report.
Signs of a clocked car — physical checks
Now look at the car itself. It often gives the game away.
- Steering wheels, gear knobs and pedal rubbers wear with use. A shiny, smooth wheel or worn-through pedal rubbers on a low-mileage car don't add up.
- A sagging driver's seat, worn bolsters and a scuffed, tired cabin all point to more miles than claimed.
- Tyres, brakes and other wear parts should look consistent with the mileage. Suspiciously new tyres can be innocent, but combined with other flags they're worth questioning.
- On older cars with mechanical dials, study the instrument cluster. Mismatched or loose screws, misaligned digits, or panel gaps suggest it's been apart. That mainly applies to analogue clocks: a modern digital odometer altered through the diagnostic port typically leaves no physical trace, so passing this check alone proves nothing.
Other red flags worth trusting your gut on
- The price sits noticeably below market for the claimed mileage. A genuine bargain is possible, but ask why it's cheap.
- The seller won't produce the service history or old MOT certificates, or gets defensive when you ask.
- The mileage changed between the online advert and the car in front of you.
Any one of these might be nothing. Two or three together, and the free MOT check becomes non-negotiable before you go any further.
What to do if you think you've bought a clocked car
Don't panic, and don't bin anything. Gather your evidence first: a printout or screenshot of the MOT mileage history, the advert, and any messages with the seller. Then the service records, and a dated photo of the current reading.
Raise it with the seller. If that goes nowhere, report it to Trading Standards through the Citizens Advice consumer service, which passes reports on to them. Suspect deliberate fraud? You can report it to Action Fraud as well.
What you can recover depends on whether you bought from a trader or privately. Check the specific guidance on Citizens Advice or Action Fraud, or get proper advice, before you decide your next move.
While you're checking history, look for the other nasty surprises. A write-off marker or outstanding finance can matter just as much as the mileage. See our guides to Cat N cars and Cat S cars for what those markers mean.
FAQs
Is mileage clocking illegal in the UK?
Selling a car on a false mileage is against the law. For traders it's a criminal offence under the Digital Markets, Competition and Consumers Act 2024, in force since 6 April 2025 and replacing the older 2008 regulations. It covers altering an odometer, or supplying, advertising or describing a vehicle with a mileage they know or suspect is false. A private seller isn't caught by that criminal offence but can still be liable for misrepresentation.
How can I check if a car's mileage has been tampered with?
Start with the free MOT history. The mileage should rise consistently and never fall between tests. Cross-check it against the service book, and look at physical wear on the steering wheel, pedals and seats. A paid history check adds finance, write-off and mileage-record data where the free trail is thin.
Can the MOT history check catch a clocked car?
Often, yes. It's the most reliable free check you have. It shows the recorded mileage at every MOT back to 2005, so any drop or implausible jump between tests stands out. It won't catch clocking done before a car's first MOT, or in the gaps between tests. That's why the service history and physical checks still matter.
What should I do if I think I've bought a clocked car?
Gather your evidence: MOT history, advert, seller messages, service records, a photo of the current reading. Raise it with the seller. If that fails, report it to Trading Standards via the Citizens Advice consumer service. Or to Action Fraud, if you suspect deliberate fraud.
Can electric cars and newer digital odometers be clocked?
Yes. Digital odometers are altered electronically through the car's diagnostic port, rather than by winding a dial. That often leaves no visible trace on the dashboard. The MOT and service-history cross-checks work just as well on newer and electric cars.
Does a low price mean a car is more likely to be clocked?
Not on its own. Some cheap cars are just cheap. But a price well below market for the claimed mileage is a prompt to run the free MOT check. And to look hard at the wear and paperwork before committing.