Updated May 2026
Advisory vs fail vs dangerous defect — what's the difference?
Since May 2018 every UK MOT defect is logged as minor (pass-with-advisory), major (fail), or dangerous (fail and do-not-drive). Anything older than that uses the previous pass/advisory/fail language. MOT Checkup surfaces all three categories on every free MOT check.
TL;DR
- Advisory / Minor — pass; fix when convenient
- Major — fail; cannot drive on public road unless old MOT still valid
- Dangerous — fail; do not drive at all
- System introduced May 2018, replacing the earlier categories
The three categories in detail
| Category | MOT result | Action |
|---|---|---|
| Advisory | Pass | Plan repair before next MOT |
| Minor | Pass with note | Fix soon — repeat-testers may upgrade to major next year |
| Major | Fail | Repair before driving (unless old certificate still valid) |
| Dangerous | Fail | Do not drive on a public road |
See our advisory vs minor defect deep-dive for examples drawn from real MOT records.
The can-I-drive matrix
- Advisory or minor — drive normally. The car is roadworthy on the day of the test.
- Major fail, previous MOT still valid — you can usually drive away to a repair location. The previous certificate keeps you legal until it expires.
- Major fail, previous MOT expired — you cannot drive on a public road. Repair on-site or arrange recovery.
- Dangerous fail — do not drive on a public road under any circumstances. Driving in a dangerous condition is a separate offence carrying up to £2,500 and 3 points.
Examples of each
- Advisory: Tyre tread approaching legal limit (~3mm); rear shock absorber slightly weeping; brake disc lightly pitted.
- Minor: Number plate lamp blown; offside indicator lens cracked; small windscreen chip outside the swept area.
- Major: Tyre tread below 1.6mm; brake pads worn to backing plate; suspension joint with excessive play; emissions beyond limit.
- Dangerous: Sidewall split with cords visible; brake fluid leak onto a hot disc; corroded chassis member in a prescribed area; steering rack mounting failed.
How the categories interact with retesting
Major and dangerous defects both fail the MOT. The retest rules are the same — partial retest free at the same station within 10 working days. The difference is whether you can drive there. See MOT cost and can I drive without an MOT for the full retest and exception rules. Our methodology explains how we cross-reference DVSA category data.
Frequently asked questions
Did the MOT categories change in 2018?
Yes. May 2018 introduced the current minor / major / dangerous categorisation, replacing the previous simpler pass / advisory / fail. The change brought UK MOT terminology in line with EU testing standards. Pre-2018 records use the older language, which is why historic MOT history sometimes reads differently from recent tests.
Can I drive home with an MOT advisory?
Yes — an advisory is a pass with a warning. The car is roadworthy on the day of the test. The tester is flagging wear that hasn't yet failed the standard but probably will at the next test. You don't need to fix it immediately, but you should plan to.
Can I drive a car with a major (fail) defect?
Generally no. If the previous MOT certificate has not yet expired and the defect is major rather than dangerous, you may be able to drive away from the test station to a place of repair. If the previous MOT has expired, you cannot drive on a public road. See our 'can I drive without an MOT' answer for the full rules.
What does a dangerous defect mean for my insurance?
Driving a vehicle with a dangerous defect is a separate offence carrying up to a £2,500 fine and 3 penalty points, on top of any no-MOT offence. Most insurance policies are voided when the vehicle is being used in a dangerous condition — you would have no cover for any claim arising from a collision.
Why do my MOT history records show advisories on items that failed later?
Advisories are predictive. The tester is saying 'this will fail at next year's test if you don't act'. About 60% of advisories on common wear items (brake pads, tyres, joints) appear as fails on the subsequent test. Use the advisory list as a planning tool, not a problem to ignore.