When your car comes back from its MOT test, the certificate doesn’t just say “pass” or “fail” anymore. Since 20 May 2018, the DVSA has graded every fault it finds into a strict hierarchy of defect categories. Understanding that hierarchy is the difference between knowing your car is genuinely safe and just assuming it is because it has a green certificate.
This guide breaks down all five results you might see on a UK MOT: Pass, Advisory, Minor, Major, and Dangerous. It covers what each one actually means for your safety, your insurance, and your legal right to drive, plus the latest figures on how often each one comes up.
Before 2018, the MOT system worked on a simpler idea. A car passed, or it failed, with a loose list of “advisories” attached almost as an afterthought. That changed when Great Britain aligned its testing rules with the EU roadworthiness testing directive (2014/45/EU), replacing the old binary system with a structured framework built around risk, not just presence of a fault.
Today, when a DVSA approved tester finds a problem, they don’t eyeball its severity. They match it against the official MOT Inspection Manual, which defines the exact category for that specific fault on that specific component. A worn tyre isn’t just “a worn tyre.” Depending on tread depth, it’s classified as fine, an advisory, or an automatic fail. This removes most of the guesswork, though testers still apply judgement to borderline cases such as corrosion depth and location.
For the full walkthrough of what happens during the test itself, from booking to the checks under the vehicle, see our complete guide to the MOT test.
This is the result every driver wants: no defects of any kind were found, in any category. Your vehicle meets the minimum legal safety and environmental standard, and you’re issued a standard MOT pass certificate. A clean pass simply confirms the car is roadworthy on the day of the test. It isn’t a certification of overall condition, and it doesn’t mean nothing will need attention before next year.
An advisory isn’t technically a defect category at all. It’s a note, not a fault classification, and it has zero effect on the test result. Your car still passes. Testers use an advisory to flag something that’s beginning to wear out or is approaching the end of its useful life, using standardised phrasing like “worn but not excessively,” “slightly damaged,” or “approaching the legal limit.”
Common advisories include:
Here’s the number that matters. DVSA data consistently shows something that’s an advisory this year has a real chance of becoming a Minor or Major defect at next year’s test if nothing is done. Treat an advisory as a maintenance to-do list, not something to file away and forget.
A Minor defect is where the modern system most closely resembles the old “advisory” concept, but formalised. It has no significant effect on safety or the environment at the time of the test, so the vehicle still meets the legal MOT standard and receives a pass. The defect is, however, printed on the certificate as a permanent record.
Typical Minor defects include a slightly worn brake pad still above minimum thickness, a small, non-dripping oil leak, or a stone chip on the windscreen outside the driver’s critical zone of vision. The instruction from every tester is the same: fix it as soon as practical, because left alone it can escalate.
A Major defect means your car has failed the MOT. The DVSA defines it as something that “may affect the vehicle’s safety, put other road users at risk, or have an impact on the environment.” The vehicle needs the defect repaired and must be retested before it can pass.
Crucially, a Major defect does not automatically ground your car on the spot. If your previous MOT certificate is still valid and the vehicle was genuinely roadworthy going into the test, you can usually still drive it home or to a pre-booked repair. But this isn’t licence to keep driving on it. If police or a DVSA examiner judge the fault makes the car unsafe, they can still treat it as an unroadworthy vehicle regardless of what the paperwork says. The message from testers is consistent: a Major defect means fix it now, not “get round to it.”
This is the most serious result on the scale. A Dangerous defect represents a direct and immediate risk to road safety or has a severe impact on the environment. The vehicle fails the MOT, and unlike a Major defect, you must not drive it at all until the fault is repaired, except to a pre-arranged MOT retest or repair, and only if it’s safe to do so.
There’s a real financial risk attached too. Driving a vehicle recorded with a Dangerous defect can mean your insurance cover becomes void, on top of the standard penalties for driving an unroadworthy vehicle. If you’re told your car has a Dangerous defect, the safest and legally correct move is to have it recovered or repaired at the test centre rather than drive it anywhere.
The same underlying problem, corrosion for instance, can land in any of the three fail or pass affecting categories depending on context. The tester weighs:
Light surface rust on a non-critical panel is typically Minor. More advanced corrosion in an important structural area becomes Major. If the metal has thinned to the point a mounting could genuinely fail, it’s marked Dangerous. The same logic applies to brakes, steering joints, tyres, and wheels. Precise thresholds exist in the manual, but professional judgement still governs the close calls.
For brake specific examples: if the braking effort on one wheel drops below 70% of the maximum recorded on the opposite wheel of the same axle, that’s a Major defect. If a steered axle wheel drops below 50% of its opposite number, that becomes Dangerous.
Since 2026, testers are also required to capture digital photographic evidence for Dangerous defects, Major defects, and certain advisory items, stored against the vehicle’s MOT record and viewable through the government’s MOT history checker. This adds a layer of transparency if you ever want to challenge a result or check a used car’s history before buying.
If your car fails on a Major or Dangerous defect, you don’t necessarily have to pay for a full retest:
The pattern across all of this data points the same way. Most MOT failures aren’t catastrophic engineering problems. They’re cheap, visible, easily checked items, such as a blown bulb, a worn wiper blade, or a tyre a few millimetres past its limit, that a five minute pre-test walkaround would catch. For the full breakdown of what fails most often and how to avoid it, read our guide to the most common MOT failures in the UK.
| Category | Test Result | Can You Drive It? |
|---|---|---|
| Pass | Pass | Yes, no restrictions |
| Advisory | Pass | Yes, note it for future maintenance |
| Minor | Pass | Yes, repair as soon as practical |
| Major | Fail | Only if previous MOT is valid and car is genuinely roadworthy, and only to repair or retest |
| Dangerous | Fail | No. Do not drive under any circumstances until repaired |
Is an MOT advisory the same as a Minor defect? No. A Minor defect is a formal defect category recorded against the legal MOT standard. An advisory is a separate, informal note about wear that hasn’t yet reached defect level. Both let the car pass, but only Minor defects are graded within the official three-tier fail-risk hierarchy.
Can I drive with a Major defect if my current MOT hasn’t expired yet? Generally yes, but only if the vehicle is genuinely roadworthy and you’re driving to a pre-booked repair or retest. If the fault actually makes the car unsafe, driving it can still be treated as a roadworthiness offence regardless of certificate status.
Does a Dangerous defect always mean an instant fail? Yes. A Dangerous defect fails the MOT outright, and the vehicle must not be driven on public roads at all until it’s fixed, other than the narrow exception of getting it to a repair or retest.
How long do I have to fix a defect before it affects my insurance? There’s no grace period for a Dangerous defect. Driving with one risks voiding your cover immediately. For Minor and advisory items, insurers generally expect reasonable diligence, so addressing them before your next MOT is the safer course.
Ready to book your MOT? Book your MOT in Worthing with our DVSA-approved test centre, or check when your MOT is due using our free lookup tool.