What does an MOT advisory mean, and will it fail next time?

An MOT advisory is the tester's note that an item is wearing but has not reached the limit that would make it a defect, so it is not a failure and never becomes one by itself. It only matters at the next test if that item has worn past its limit by then. DVSA grades defects Minor, Major or Dangerous, and a Minor defect still passes.

An advisory is a note, not a defect

An advisory describes something that is worn, damaged or beginning to deteriorate, but that has not reached the point where the rules call it a defect. It is written down so the owner knows about it, not because the test has found a reason to refuse a certificate. An advisory is information to act on when the item needs it, and it carries no weight in the result. Nor does it tell you the result on its own: advisories are recorded on the test outcome either way, so a car refused a certificate for a Major defect can still have advisories listed about other items.

What an advisory does do is describe the vehicle on the day of the test. It is a single observation by one tester at one moment, which is why a run of certificates is more informative than the most recent one. An advisory repeated at consecutive tests and never resolved says something quite different from an advisory that appears once and is gone the following year.

Minor, Major and Dangerous: the grading people confuse with an advisory

Every defect found at an MOT is graded. The grade, not the existence of the defect, decides the result — and a Minor defect passes. This is the point most often misread: a result can list both advisories and Minor defects and still be a pass.

An advisory sits outside this scale altogether. A Minor defect is a defect that has been judged not serious enough to fail; an advisory is a note about something that has not been judged a defect at all. Neither one is a failure, and neither one can cause a failure on its own.

Will it fail next time? What the answer actually depends on

Nothing carries over. At the next test the vehicle is assessed from scratch against the same limits, and last year's advisory has no status in that assessment. So the question is not whether an advisory becomes a failure — it cannot — but whether the underlying item will have crossed its own pass limit by the time the tester looks at it again. That turns on one thing: whether the item goes on getting worse without anyone touching it.

• Advisories on wearing parts move towards a failure. Tyres, brake components and corrosion all deteriorate with use and time. An advisory here is a warning about direction of travel, and the more miles driven between tests, the more likely the item is to have crossed the line.
• Advisories on static observations often do not. A previous repair the tester wanted on record, or damage that is not deteriorating, can be noted at test after test without ever affecting a result.
• Mileage between tests matters more than the wording. The same advisory on a car covering a few thousand miles a year and on one covering many times that describes two quite different risks for the next test.

If one advisory deserves more attention than the rest, it is a tyre. DVSA's 2024/25 figures show tyres accounted for 60.12% of all dangerous defects, ahead of brakes at 29.01% and suspension at 5.34%. Tyres are both the component most often found in a dangerous condition and one that wears with every mile.

What actually fails an MOT, by the numbers

DVSA recorded 35,229,047 tests in Great Britain across all vehicle classes in 2024/25. Within classes 3 and 4, which cover cars and similar vehicles, the initial failure rate was 28.08%, with an average of 2.44 defects per initial failure, and at least one dangerous defect was found in 7.70% of tests. The categories below are ordered by how often they were recorded.

Source: DVSA MOT testing data 2024/25, classes 3 and 4, Great Britain. Lighting leads on volume; tyres lead on severity. An advisory in either category is worth reading twice, for different reasons.

Great Britain and Northern Ireland are tested differently

The MOT is not one scheme across the whole United Kingdom. DVSA is responsible for testing in Great Britain; in Northern Ireland the test is carried out by the DVA. The differences are not cosmetic.

• First test. The third anniversary of registration in Great Britain, four years in Northern Ireland.
• Fees. A maximum of £54.85 for a class 4 vehicle in Great Britain, and a garage may charge less. In Northern Ireland the full test is £38.00 and a retest is £29.50. These figures are maximums, free of VAT, and unchanged since 2010.
• Public history. Past results and advisories are published back to 2005 in England, Scotland and Wales, but only back to 2017 in Northern Ireland — so a Northern Ireland car will usually have a shorter record to read.
• Historic exemption. In Great Britain a vehicle built or first registered more than 40 years ago, with no substantial changes in the last 30, is exempt from testing. The exemption is automatic and declared on form V112. It does not cover substantially changed vehicles, Q-plated vehicles, kit cars, kit conversions or DVLA-defined reconstructed classics, and it is a separate thing from the historic vehicle tax exemption, which has to be applied for. This is the Great Britain rule, and it does not describe the Northern Ireland position, where the DVA runs its own scheme.

Reading the advisories on a car you are considering

The public MOT history service publishes every past result, the advisories written at each test and the mileage recorded on the day. Three things are worth doing with it. Read the advisories in sequence rather than one at a time, so a repeat becomes visible. Compare the recorded mileages between tests, because the same advisory means more on a car covering high mileage. And note which advisories vanished, since that is the closest thing to evidence the work was actually done.

Our MOT check tool works out when a vehicle's next test is due, and the most reliable used cars guide covers the models whose known faults tend to show up in advisories first. Unfamiliar terms on a certificate are defined in the car buying glossary.

Related pages

• MOT check — when the next test falls due.
• Car tax calculator — vehicle tax is a separate obligation from the test.
• Vehicle tax when buying a used car — what happens to the tax on a change of keeper.
• Most reliable used cars in the UK
• Compare cars side by side

Statistics on this page are DVSA MOT testing data for 2024/25 (classes 3 and 4 unless stated) and published maximum test fees. Verified 9 September 2026. Testing rules described as applying to Great Britain do not apply in Northern Ireland, where the DVA operates a separate scheme.