Reading an MOT history: what advisories actually mean
Plain-English breakdown of DVSA MOT records: pass, fail, dangerous, advisory, and the recurring-fault patterns that quietly tell you the car has a problem.
Every pass is just today's snapshot. The pattern is the real story.
- Free & publicMOT history is available for every UK vehicle, with no login or fee.
- More than a passThe pattern of advisories reveals how the car has been maintained.
- Spot problems earlyRepeated advisories are early red flags long before a failure.
- Know the limitsIt is a basic roadworthiness check, not a mechanical inspection.
- Use it before you buyThe cheapest way to avoid a wasted viewing and a costly surprise.
What the MOT is, and what it isn't
The MOT is a basic roadworthiness check, not a full mechanical inspection. A tester spends roughly 45 minutes checking that lights, brakes, tyres, steering, suspension, seatbelts, exhaust emissions, the windscreen and a few other safety items meet the legal minimum on the day of the test.
It does not check the engine internals, the gearbox or clutch, the cambelt, the air-conditioning, ECU faults, whether the service history is genuine, or whether the car has been crashed and repaired.
A car can sail through an MOT and have a worn clutch, a dripping head gasket, a coming-soon turbo failure and a clocked odometer. The MOT is a floor, not a quality rating.
The four MOT outcomes
Since the DVSA rules changed in May 2018, an inspection ends in one of these results.
Pass
Vehicle meets the minimum standard. The tester may still note advisories.
Pass with advisories
A pass, but with items flagged that are legal now and won't be for long.
Fail with a major defect
An item is below the legal standard. Not allowed back on the road until fixed and re-tested.
Fail with a dangerous defect
A danger to road users right now. It must not be driven away from the test centre.
You might see "Refused" instead of "Fail". That means the tester couldn't start the test: usually the registration didn't match, or the vehicle wouldn't start. It isn't a roadworthiness signal either way.
Defect ranking: what the terms mean
Minor defect
Doesn't affect safety significantly. Logged on the certificate but doesn't cause a fail. Treat the same as an advisory.
Major defect
Affects safety or the environment. Causes an immediate fail.
Dangerous defect
Immediate risk to road users. Causes a fail, and the vehicle is officially not roadworthy from that moment.
Before May 2018
Older records say "Advisory notice" rather than "Minor defect". They mean roughly the same thing, but an advisory in 2017 might be a minor or even a major under today's rules.
What advisories actually warn you about
An advisory isn't a defect yet: it's the tester saying this will fail next year if you don't fix it.
Tyres & wheels
- Tyre slightly damaged or cut, usually a sidewall scuff
- Worn close to the legal limit (1.6mm)
- TWI showing: you are at the limit; fail material
- Inner/outer edge worn: geometry is out
Budget for tyres and an alignment.
Brakes
- Disc worn but not seriously weakened
- Pads wearing thin, often paired with the disc advisory
- Pipe corroded but not seriously weakened
Fix corroded pipes early: once one leaks under pressure you have no brakes at that corner.
Suspension
- Anti-roll bar linkage has slight play (drop links)
- Shock absorber slightly misting oil
- Coil spring corroded, usually cosmetic until one fractures
Often cheap now, expensive later if ignored.
Body & structure
- Corrosion noted but doesn't significantly reduce strength
- Repeated over two or three MOTs: the bodywork is rusting in earnest
"Doesn't significantly reduce" is the tester saying "not yet". Check this car in person very carefully.
Lights & electrical
- Headlamp aim too high or low
- Wiper not effective: blades worn, trivial
- Suspect electrical wiring: something has been bodged
Usually minor and cheap, but repeated lighting advisories can mean a disturbed wiring loom after a body repair.
Recurring patterns that matter
One advisory is information. The same advisory again and again is a warning.
Same advisory, multiple MOTs
The owner hasn't fixed it and probably won't start now. Tyres or brakes flagged three years running means you inherit the bill.
Corrosion year on year
The metal is rotting and nobody is treating it. By the third or fourth such advisory, plan a bodyshop visit or walk away.
Suspiciously clean record
On a ten-year-old car, zero advisories ever is almost too clean. Cross-check the mileage progression.
Mileage that doesn't add up
A reading that drops, a flat year, or a sudden jump. The DVSA records a backwards reading explicitly.
Treat a pattern, not a single data point
The MOT history tells you how the car has been treated over years, not just today.
The mileage column: where clocking shows up
Every MOT records the odometer reading at the time of the test, and the DVSA publishes those readings. A car averaging 8,000–12,000 miles a year is normal; big swings aren't fatal but should have a story.
A reading that goes down between tests shouldn't happen; walk away unless the seller can document an instrument cluster replacement. Mileage barely changing on a car advertised as "low mileage" is worth pulling the record yourself: some sellers omit the most recent MOT from photos of the V5C, and the digital record is the only honest source.
A realistic example: what a bad pattern looks like
Every test below is a pass or a fixed fail. Read together, the record still tells you to be careful.
| Test date | Mileage | Result | Advisories and defects |
|---|---|---|---|
| Mar 2021 | 58,120 | Pass | Nearside front tyre worn close to legal limit |
| Mar 2022 | 69,430 | Pass | Nearside front tyre worn close to legal limit · Corrosion noted, doesn't significantly reduce strength |
| Apr 2023 | 80,905 | Fail | Major: brake pipe excessively corroded · Corrosion noted (sill) |
| Apr 2023 | 80,905 | Pass | Retest after repair · Corrosion noted (sill) |
| May 2024 | 91,260 | Pass | Corrosion noted (sill, offside) · Anti-roll bar linkage slight play |
Illustrative example, not a real vehicle's DVSA record.
What this record is telling you
- The same nearside tyre advisory appears twice before anything is done about it.
- Corrosion is noted in three consecutive years and spreads from one sill to the other; the "doesn't significantly reduce strength" wording is doing a lot of work.
- A corroded brake pipe became a major fail. That is the pipe advisory arriving as a bill.
- Mileage climbs steadily at around 11,000 a year, which is the one genuinely reassuring thing here.
When to bother with a pre-purchase inspection
The MOT history can save you from buying a car with obvious recurring issues. It cannot replace a mechanical inspection on the car you are seriously considering. Use it as the first filter: if the history is clean of patterns, then pay £100–£200 for an AA, RAC or independent inspection on a car you have test-driven and like. Spending an hour reading three or four MOT histories before viewing means you only go and see the cars whose records hold up.
Final checklist: ten minutes per shortlisted car
- 1Pull the registration on gov.uk/check-mot-history.
- 2Skim every result in chronological order and note the most recent one.
- 3Look for any "Dangerous" defect ever recorded.
- 4Read the latest advisories; those are the items you inherit.
- 5Look for repeated advisories in the same category across tests.
- 6Sanity-check mileage: years on the road × ~10,000 should land near the odometer.
- 7Cross-check the test centre location against where the seller says it's been kept.
Check the full picture before you buy
CompareForecourt pulls the complete MOT history, highlights the patterns that matter, and helps you compare similar vehicles with confidence.
- Full MOT history & advisories
- Spot recurring issues
- Compare similar cars side by side
- Estimate running costs & tax
