MOT advisories: what they mean and which ones become failures
An advisory is an item the tester noticed that passed today but is wearing. It does not fail the car, it is not a legal requirement to fix, and it stays on the record for anyone who checks the history. Whether it matters depends on which component it is on, and we can put a number on that, because we followed 51,588,977 advisories through to the same car's next test.
How often an advisory becomes a failure
An advisory on lights is the one to act on: 36.1% of cars given one failed on that component at the next MOT. At the other end, fuel and oil leaks advisories turned into a failure only 1.3% of the time.
Share of cars with an advisory in each category that failed on that category at their next test. Based on 51,588,977 advisories with a following test on record, from the DVSA dataset for 2023 to 2025.
The four defect categories
Passed, but wearing. No action required by law. The most useful line on any MOT history, because it is the tester telling you what fails next.
A defect that does not fail the test. Recorded, should be fixed, but the certificate is issued.
Fails the test. The car cannot be issued a certificate until it is repaired and retested.
Fails the test and must not be driven, even away from the test station, until repaired. Driving it is an offence.
Buying a used car: how to read the advisories
Look at the last two tests together. An advisory that appears twice has been ignored for a year. An advisory on tyres or brakes with a "close to limit" wording is a repair bill within months. An advisory on corrosion is the one to take seriously on any car over ten years old, because it only goes one way. The model pages list the advisories each car usually collects, so you can tell a normal one from a warning sign.
The history is free to check and the seller cannot alter it. Check a registration and the report shows each current advisory with the rate at which that kind of advisory became a failure. If the certificate is due soon, the test centre directory has every station by town.
Questions people ask
Do I have to fix an MOT advisory?
No. An advisory does not fail the test and there is no legal requirement to act on it. But the tester expects it to fail next time, and a tyre or brake advisory can become a police matter before then if it crosses the legal limit.
Can an advisory be removed from the record?
No. It stays on the DVSA history permanently, whether or not it was fixed. A buyer will see it, which is a reason to keep receipts for the repair.
Why did my car pass with several advisories?
Because none of them had reached the failure threshold on the day. Advisories are the tester's judgement about direction, not a failure.
What is the difference between an advisory and a minor defect?
A minor defect is a fault that exists now but is not serious enough to fail the car; it should be repaired. An advisory is an item that is still within limits but wearing. Both are recorded and neither fails the test; major and dangerous defects do.
Which advisories matter most when buying a used car?
Those on components that fail most often next time: lights (36.1%) and suspension and steering (22.4%). Corrosion advisories matter on cars over ten years old because rust only goes one way. An advisory that appears on two consecutive certificates has been ignored for a year.
Conversion rates from the DVSA anonymised MOT tests and results dataset, following each vehicle between consecutive tests. Methodology.