Why the Categories Were Introduced
Since 2018, the MOT test has used four defect categories rather than a simple pass or fail: minor, major, dangerous, and advisory. This gives drivers a clearer picture of exactly how serious a fault is, and whether the car remains legal and safe to drive.
Advisory
An advisory is a note about something that isn't a legal problem yet, but is worth keeping an eye on — for example, tyres approaching the legal tread limit, or a slight brake fluid weep. Advisories don't affect whether the car passes; the vehicle gets a full MOT certificate regardless.
Minor
A minor defect has no significant effect on safety or the environment and doesn't cause the vehicle to fail. It's recorded on the certificate as a minor item to be monitored and, ideally, repaired soon, but the car still passes overall.
Major
A major defect is more serious — it "may affect the vehicle's safety, put other road users at risk, or affect the environment," and results in an outright MOT failure. The vehicle cannot legally be used on the road for normal journeys until the fault is repaired, unless the existing MOT certificate hasn't yet expired (in which case you can drive until that expiry date, though it's not advisable if the fault is genuinely safety-related).
Dangerous
A dangerous defect is the most serious category — it represents "a direct and immediate risk to road safety or has a serious impact on the environment." A car with a dangerous defect must not be driven under any circumstances until it's repaired, even if the existing MOT certificate technically hasn't expired yet. Driving with a known dangerous defect can result in a fine of up to £2,500, penalty points, and a driving ban.
| Category | Affects pass/fail? | Can you drive? |
|---|---|---|
| Advisory | No | Yes, as normal |
| Minor | No — still passes | Yes, as normal |
| Major | Yes — fails the test | Only if the previous MOT certificate is still valid |
| Dangerous | Yes — fails the test | No — under no circumstances |
What to Do Next
Whatever category your defects fall into, we'll always explain what each item means in plain English and give you a written quote before carrying out any repair work. If you're bringing your car back for a retest, our guide to MOT retests and fees explains what you'll pay depending on timing.
Book Your MOT with Autoclinics High Wycombe
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