Most advice on clocked cars tells you to look at the pedal rubbers and the shine on the steering wheel. That's fine as far as it goes, but a decent clocker knows about pedal rubbers too, and a new set costs about a fiver.
The reading you actually want is free, takes a minute, and lives on a government website. Here's how to read it properly.
What is a clocked car?
A clocked car is one whose odometer has been wound back so it shows fewer miles than it's actually done. The point is money: mileage is one of the biggest levers on a used car's value, so knocking 40,000 miles off a reading can add well over a thousand pounds to the asking price in an afternoon.
It used to mean physically spinning the numbers on a mechanical dial. Now it's a laptop, a cable into the OBD port and a few minutes in a car park. Digital dashboards made the job faster and quieter, not harder, and the tools to do it are sold openly as "mileage correction" kit.
HPI, who sell vehicle checks and so have an interest in the number being alarming, say 1 in 11 vehicles they check has a mileage discrepancy. Treat that as the top of the range rather than the national rate, but it's the right order of magnitude for the sort of cars people bother getting checked.
Is clocking illegal in the UK?
Changing the reading isn't itself an offence. Selling the car without telling the buyer is.
That distinction catches people out, so it's worth being clear about. There are legitimate reasons a reading changes: replace a failed instrument cluster and the new one starts from whatever it starts from. What the law goes after is the misrepresentation, not the screwdriver. Knowingly selling a car on a false mileage is a misleading action under the Consumer Protection from Unfair Trading Regulations 2008, and it can be fraud as well.
How do you check a car's mileage history for free?
Put the registration into the DVSA's MOT history service. It lists every MOT the car has had, and every one of them records the mileage on the day of the test.
That's the whole trick, and it costs nothing. Cars, vans and motorbikes have results going back to 2005, and Northern Ireland from 2017. You get a dated sequence of readings taken by a tester who had no reason to flatter the car, which is the closest thing to an honest record a used car has.
Don't just look at the last figure. Write the sequence out, oldest first, and work out the gap between each pair. It's the gaps that talk.
If you'd rather not do that on your phone at the kerbside, our free scan draws the same sequence as a graph and marks the years that don't fit. More on that below. The raw data is free either way, and it's the same data.
Check the history before you hand over money
A Provenance Check covers the four things no free lookup includes: outstanding finance, theft markers, insurance write-off category and recorded mileage discrepancies.
Run a provenance check →What does a clocked MOT history actually look like?
Rarely like the thing everyone watches for. A reading that goes backwards is the easiest fraud to catch and therefore the least common, because it fails the free check anyone can run. These are the shapes that actually turn up.
| What you see | What it usually means |
|---|---|
| A reading lower than the one before it | Straightforward clocking, or a typo by the tester. Two adjacent years disagreeing by a few hundred miles is a fat finger. A drop of 30,000 isn't |
| One year at 3,000 miles sat between years at 15,000 | Either the car genuinely sat unused, or the clock was wound and the next tester recorded what he was shown |
| Big miles for years, then a flat spell right before sale | The most common shape by far. The car was corrected once, recently, and the history hasn't caught up with the story yet |
| A long gap with no MOT at all, then a modest reading | Nothing was recorded while the car was off the road, so nothing had to stay consistent. Worth the most suspicion of the lot |
| A car under three years old with one test or none | There's no history to check yet. See the next section |
The single most useful question to ask of the sequence: does the pattern change at the point the car last changed hands? A car that did 18,000 a year for six years under a company and 4,000 a year since might have moved to a retired owner. Or the current keeper bought a high-miler, corrected it, and is selling it as a low one. Ask who owned it and when, then see whether the answer matches the shape of the numbers.
What can't the MOT record show you?
Plenty, and this is the part the free-check articles skip.
It can't see between tests. Readings are annual snapshots. A car clocked in March and tested in April simply shows the corrected figure, and every reading after that is consistent with it. The record is only ever as honest as the day it was taken.
It can't see the first three years. Cars don't need an MOT until the third anniversary of registration, so a nearly-new car has no independent mileage record at all. Nothing to check, which is why the youngest cars need the paperwork trail instead.
It can't see before 2005. Older cars and classics have a blank at the start of their lives, because that's when the digital record began.
It doesn't flag anything. The service shows you numbers. It won't tell you a sequence is odd, which is exactly how people scroll past a discrepancy that's sitting there in plain text. This is one of the things a free check will never do for you.
The wider mileage register is the gap-filler. It collects readings from services, sales, finance applications and insurance work rather than just MOTs, so it picks up figures recorded between tests and before the car turned three. That's what turns "the MOT history looks fine" into "every recorded reading in this car's life agrees", and it's why a proper mileage check sits alongside finance and write-off data rather than with the free stuff.
Can anything read that sequence for you?
That last gap is the one worth closing, because it isn't a gap in the data. The numbers are right there on gov.uk, free, for anyone. The problem is that they arrive as a plain table and nothing in it points at the year that doesn't fit.
Our free scan plots the whole sequence as a graph and marks the shapes for you. It flags a reading that drops below the one before it, a year that sits almost flat among busy ones, a sudden surge well above what that particular car normally does, and the stored-then-driven-hard pattern where a long idle stretch is followed immediately by a spike. They're the same four shapes as the table further up this page, and each flagged segment comes with a line explaining what that shape usually means and what to ask the seller about it. You can see one on our sample report.
It also does the one check gov.uk structurally cannot: it compares the mileage the seller put in the advert against the most recent MOT reading. If the advert claims fewer miles than the car has already officially recorded, that's flagged straight away. The MOT service has never seen the advert, so it can't catch that no matter how carefully you read it.
None of this proves a car's been clocked. A flat year is often just a flat year. What it does is stop you scrolling past the one that isn't, which is how most clocked cars get sold: not to people who checked and were fooled, but to people who looked at the last number and moved on.
If you want the gaps filled as well as the sequence read, that's the Provenance Check. It adds the wider mileage register described above, so readings taken between MOTs, and before the car turned three, come into the picture, and the result is scored into the report's verdict rather than listed beside it. It includes the full Smart Check too, so the known faults, the repair costs and the questions to put to the seller come with it.
What should you look at on the car itself?
Physical tells are worth a look, but rank them properly: they're corroboration, not evidence. Anyone who'll spend an hour on the dashboard will spend a fiver on pedal rubbers.
- The service book and the invoices. Every stamp and every garage bill carries a mileage. This is the strongest paper record there is, because a clocker has to forge a dozen documents rather than edit one number. A full history that agrees with the MOT record is very hard to fake, which is also why a car with no history at all needs the MOT sequence doing twice as carefully.
- Wear against the claim. A 45,000-mile car with a polished gear knob, a collapsed driver's seat bolster, a worn key and its third set of tyres is telling you something the dash isn't. Look at the bits nobody thinks to replace: seat belt webbing, the driver's door handle, the boot floor.
- Old MOT certificates in the folder. The paper ones carry the reading too, and sellers often hand over a wallet of them without ever having read them.
- The car's own weak spots. Known faults tend to arrive at a mileage. A BMW 3 Series or Audi A4 showing wear that normally turns up at 120,000 while the clock says 60,000 is a real signal. Same for the motorway staples like the VW Passat and the Mercedes C-Class, which are precisely the cars that do big company miles and are therefore worth the most to clock.
What should you do if you think a car's been clocked?
Walk away first, then report it. In that order.
There's no version of this where you buy the car and sort it out afterwards. If the mileage is wrong, the seller either knows, in which case ask yourself what else they're saying, or doesn't, in which case they can't answer a single question about the car's history. Neither is a car you want.
If you've already bought one, you have rights against a trader under the Consumer Rights Act 2015, and you can report them to Trading Standards through the Citizens Advice consumer helpline. Against a private seller it's harder, because a private sale only has to match the description, though a false mileage is precisely that: not as described.
Before any of it, read the advert again. Clocked cars often come wrapped in wording that's doing some work: a mileage given as "approx", a service history described as "partial", a reason for selling that doesn't fit a car with that few miles on it. If the car's also had a knock, the same wording habits show up around write-off categories. The numbers and the words tend to go wrong together.
