MOT defects: dangerous, major and minor
Every fault an MOT tester finds is graded. Dangerous and major defects are a fail. Minor defects are a pass with a note. Advisories are not defects at all, but warnings, and they are the part of the record most worth reading.
Updated 14 October 2026
Dangerous: do not drive it
A dangerous defect is a direct and immediate risk to road safety or has a serious impact on the environment. The car fails, and you should not drive it until the fault is repaired, not even home.
Driving a car with a dangerous defect can bring a fine of up to £2,500, a driving ban and three penalty points. It can also invalidate your insurance. Examples include brakes that barely work, a tyre with exposed cords, or a steering component close to failing.
Major: a fail, and a repair needed
A major defect may affect the car’s safety, put other road users at risk or harm the environment. The car fails and the fault must be repaired.
Whether you can drive a car with a major defect depends on the MOT expiry date. If the old certificate is still valid and the car is roadworthy, you may legally drive it, but the fault is now on public record and you are responsible for the car’s condition. If the old certificate has expired, you can only drive it to a pre-booked repair or retest.
Minor: a pass with a note
A minor defect has no significant effect on safety or the environment. The car passes, and the fault is listed on the certificate so you can repair it soon. A slightly worn wiper or a minor oil leak are typical examples.
Advisories: the early warning
Advisories are things the tester thinks you should keep an eye on: tyres approaching the limit, light corrosion, a bush starting to perish. They do not affect the result, but they are recorded on the public MOT history.
For an owner, they are a to-do list. For a buyer, they are the most honest account of a car’s condition you will get without a mechanic: a car whose advisories are fixed between tests has been looked after, and one carrying the same advisory year after year has not.
Odomint shows every defect and advisory from every previous MOT, so you can see the pattern at a glance.
Common questions
Can I drive my car after a major MOT failure?
Only if the previous MOT certificate is still valid and the car is roadworthy, or to a pre-booked repair or retest once it has expired. With a dangerous defect you should not drive it at all.
Does a minor defect fail the MOT?
No. A minor defect is a pass, but it is recorded on the certificate and should be repaired soon.
Are advisories on the public MOT history?
Yes. Advisories, defects and mileage readings from every test are on the public record for any registration.
Check any car before you buy it
MOT history, every advisory and the full mileage record are free for any UK registration. An Odomint Check adds outstanding finance, insurance write-offs, stolen markers and salvage history, with a £10,000 data guarantee.