Every car in the UK over three years old must pass an annual MOT test to be legally driven on the road. Crucially, the result of every test — pass or fail, along with mileage and any issues found — is recorded and made publicly available through the DVSA. This creates a detailed, year-by-year history of the vehicle that any buyer can access for free.
Most buyers glance at the MOT history just to check the car has a valid certificate. That's a wasted opportunity. The full history is one of the most revealing documents available about a used car — if you know what to look for.
The four types of MOT result
Since May 2018, MOT defects are graded by severity. Understanding the difference is essential when reading a history:
| Type | What it means |
|---|---|
| Dangerous | A direct and immediate risk to road safety. Automatic fail. The car must not be driven until fixed. |
| Major | Could affect safety or the environment. Automatic fail. Must be repaired and retested. |
| Minor | No significant effect on safety. The car passes, but the issue should be repaired soon. |
| Advisory | Something to monitor — wear that may need attention in the future. The car passes. |
What advisories really tell you
Advisories are where the real insight lies. An advisory note means the tester spotted something starting to wear, but not yet bad enough to fail. Read across several years of advisories and patterns emerge that tell you how the car has been treated.
For example, an advisory for "brake disc worn, pitted or scored" one year, followed by no mention the next, suggests the owner acted on it and replaced the discs. The same advisory appearing three years running suggests an owner who ignores maintenance until it becomes a failure. That pattern tells you far more than any single test result.
Reading tip: Look for advisories that disappear in later tests — that means the work was done. Advisories that persist or worsen year after year are a sign of a neglected car.
Common advisories and what they mean
- Corrosion / corroded brake pipes — common on older cars; worth checking how advanced it is, as it can become a structural MOT failure
- Tyre worn close to the legal limit — budget for new tyres soon; check all four
- Brake disc worn or pitted — normal wear, but factor in replacement cost
- Oil leak — minor seepage is common; significant leaks can signal bigger engine issues
- Play in suspension or steering components — worth a closer look as repairs can be costly
The mileage check that catches clockers
This is one of the most powerful uses of MOT history. Every MOT test records the car's mileage. Plotted across years, that mileage should only ever increase, and at a fairly consistent rate.
If you see the recorded mileage drop between tests — say 62,000 miles one year and 48,000 the next — that's a glaring sign the odometer has been wound back, a practice known as "clocking". It's illegal, surprisingly common, and the MOT history exposes it instantly.
Even without an obvious rollback, watch for suspicious patterns: a car that covered 15,000 miles a year suddenly dropping to 2,000 miles a year right before sale can indicate the clock has been tampered with, or that the displayed mileage no longer matches reality.
Red flag: Any mileage that decreases between MOT tests is a serious warning sign. carDNA automatically flags mileage inconsistencies in the MOT history so you don't have to spot them yourself.
SEE THE FULL MOT HISTORY
Every test, every advisory, every mileage reading — free, straight from DVSA records.
Check a Vehicle →What a good MOT history looks like
When you're assessing a car, a healthy MOT history generally shows:
- A high proportion of first-time passes
- Few or no "dangerous" or "major" failures
- Advisories that are acted upon and don't recur
- Steadily increasing mileage at a consistent annual rate
- No long unexplained gaps between tests
What should make you cautious
Conversely, these patterns are worth questioning before you buy:
- Repeated failures on the same component year after year
- Multiple "dangerous" defects suggesting the car was driven in poor condition
- Mileage that drops or barely moves between tests
- A sudden flurry of repairs immediately before sale (sometimes a quick patch-up to sell)
- Gaps where the car had no MOT for a year or more
None of these is necessarily a dealbreaker on its own — but each is a question you should be able to answer before you hand over your money. A seller with nothing to hide will happily talk you through their car's history.
MOT history is only part of the picture
The MOT tells you about safety and roadworthiness over time, but it won't reveal whether a car has been written off, has outstanding finance, or has been stolen. For complete peace of mind, combine the free MOT history with a full vehicle history check before purchase.