What Fails an MOT? Most Common MOT Failures (UK)

What makes a car fail its MOT?

Your vehicle fails its MOT if the test result lists any dangerous or major problems. Minor problems and advisories do not cause a fail. The table shows what each category means.

Since 20 May 2018, defects found during an MOT in England, Scotland and Wales are categorised as dangerous, major or minor.

Which MOT defects cause a fail
Category	What it means	MOT result
Dangerous	A direct and immediate risk to road safety or a serious impact on the environment.	The vehicle fails the MOT.
Major	It may affect the vehicle’s safety, put other road users at risk or have an impact on the environment.	The vehicle fails the MOT.
Minor	No significant effect on the safety of the vehicle or impact on the environment.	The vehicle can still pass.
Advisory	It could become more serious in the future.	The vehicle can still pass.

Source: GOV.UK: MOT rule changes, 20 May 2018. Last checked 24 October 2026.

Our MOT advisories guide explains how urgent each category is.

Most common MOT failures

In DVSA’s figures for cars and light vans up to 3,000kg (classes 3 and 4), April 2025 to March 2026, the most common failure areas were lamps, reflectors and electrical equipment (24.89% of failure defects), suspension (20.49%) and brakes (15.18%). 27.51% of these tests failed as the vehicle was brought in.

Most common MOT failure areas, cars and light vans up to 3,000kg (classes 3 and 4), April 2025 to March 2026
Rank	Area (DVSA category)	Share of failure defects	Tests failed on this area
1	Lamps, reflectors and electrical equipment	24.89%	10.44%
2	Suspension	20.49%	8.90%
3	Brakes	15.18%	6.10%
4	Tyres	12.94%	6.23%
5	Visibility	7.72%	4.28%
6	Body, chassis, structure	6.26%	3.23%
7	Noise, emissions and leaks	5.89%	3.08%
8	Steering	3.59%	1.94%

Source: GOV.UK: MOT testing data for Great Britain (DVSA), table “MOT class 3 and 4 vehicles: initial failures by defect category (DVSA/MOT/03)”, April 2025 to March 2026. Last checked 25 October 2026.

The initial failure rate counts vehicles as they were brought in for the test, before any repairs. “Share of failure defects” is the area’s share of all the failure defects found; “tests failed on this area” is the share of all tests with at least one failure item in that area. DVSA says this data is not an official statistic.

The other areas (Seat belts and supplementary restraint systems, Road wheels, Identification of the vehicle, Seat belt installation check, Speedometer and speed limiter) each had 1.64% of failure defects or less.

Examples of what the MOT inspection manual fails in each of these areas:

Lamps, reflectors and electrical equipment (section 4): headlamps, stop lamps and indicators that are missing or not working.
Suspension (section 5.3): broken or seriously weakened springs, and shock absorbers that leak badly, do not work or are missing.
Brakes (section 1): pads worn down to the wear indicator, badly worn discs, and brakes below the minimum efficiency.
Tyres (section 5.2.3): tread below the legal depth, deep cuts, and lumps or bulges.
Visibility (section 3): windscreen damage in the driver’s view, and wipers or washers that do not work.
Body, chassis, structure (section 6): corrosion that weakens the structure, and doors that will not open or close properly.
Noise, emissions and leaks (section 8): emissions above the limits, a noisy or insecure exhaust, and fluid leaks.
Steering (section 2): worn steering joints and power steering faults.

What fails an MOT, area by area

In every area, a fault fails the MOT when the inspection manual lists it as major or dangerous. These are examples from the manual, in simpler words, with its category and section number.

Examples of faults that fail an MOT, by area
Area	Faults that fail, with their category	Manual section
Lights	A headlamp missing or not working: major. A stop lamp or direction indicator missing or not working: major. All stop lamps missing or not working: dangerous. An LED replacement bulb in a halogen headlamp with no approval sticker, or a sticker that cannot be read, looks tampered with or does not match the bulb: major.	4.1.1, 4.1.4, 4.3.1, 4.4.1
Tyres	Tread depth below the legal limit (for cars, 1.6mm across the central three-quarters of the tread): dangerous. A cut deep enough to reach the ply or cords: major. A lump, bulge or tear, or cords showing: dangerous.	5.2.3
Brakes	A brake pad worn down to its wear indicator: major. A brake pad worn below 1.5mm, or missing: dangerous. A brake disc significantly and obviously worn: major. Brakes below the minimum efficiency: major. Brakes at less than half the required efficiency: dangerous.	1.1.13, 1.1.14, 1.2.2
Suspension	A spring broken or seriously weakened: major. A shock absorber that does not work or leaks badly: major. A shock absorber missing or likely to come off: dangerous.	5.3.1, 5.3.2
Steering	A steering ball joint with too much wear or free play: major. A steering ball joint so worn it could come apart: dangerous. A steering rack gaiter missing or no longer keeping dirt out: major. Power steering fluid leaking or the system not working properly: major.	2.1.3, 2.1.5
Windscreen and wipers	Windscreen damage that affects the driver’s view (over 10mm across in zone A, or over 40mm elsewhere in the area the wipers clear): major. Something blocking the driver’s view through the area the wipers clear: major. A wiper missing or not working: major. Washers not working or not giving enough fluid to clear the windscreen: major.	3.1, 3.2, 3.4, 3.5
Seatbelts	A seatbelt that should be fitted is missing: major. Webbing badly stretched, damaged or weakened: major. A buckle missing, damaged or not working as it should: major. A seatbelt anchorage loose: major.	7.1.1, 7.1.2
Exhaust and emissions	An exhaust that is too noisy, or a part of it that is insecure: major. A part of the exhaust likely to fall off: dangerous. Exhaust emissions above the limits: major. Signs that the diesel particulate filter has been tampered with: major. A fluid leak that is likely to harm the environment or put other road users at risk: major.	8.1.1, 8.2.1.2, 8.2.2.1, 8.2.2.2, 8.4.1
Number plates	A plate missing or so insecure it is likely to fall off: major. Characters missing or unreadable, or the wrong registration: major. A plate that does not meet the rules, for example the size or spacing of the characters: major.	0.1
Warning lights	The engine warning light (malfunction indicator lamp) not working or showing a fault, on petrol cars first used from 1 July 2003 and diesel cars from 1 July 2008: major. The ABS warning light not working or showing a fault: major. The airbag (SRS) warning light showing a fault: major. The stability control (ESC) warning light showing a fault: major. The electronic power steering or electronic parking brake warning light showing a fault: major. The tyre pressure monitoring system obviously not working, on cars first used from 1 January 2012: major.	1.1.6, 1.6, 2.6, 5.2.3, 7.1.6, 7.12, 8.2.1.2, 8.2.2.2
Body and structure	Corrosion that makes the structure much less rigid: major. Corrosion so bad that the steering or brakes are likely to be affected: dangerous. A door that will not open or close properly: major. A boot lid or tailgate that cannot be kept shut: major.	6.1.1, 6.2.1, 6.2.3
Mirrors and horn	A required mirror missing, not working, badly damaged or insecure: major. The horn not working: major.	3.3, 7.7

LED headlamp bulbs: From 14 October 2026, MOT testers must accept ECE approved LED replacement (LEDr) bulbs in existing halogen headlamps on class 3, 4, 5 and 7 vehicles. The bulb must have a matching approval sticker from its manufacturer, fixed permanently to the vehicle where the tester can see it. The tester only checks that the sticker is there; they do not remove the lamp or the bulb. The headlamp fails, as a major defect (“light source and lamp not compatible”, section 4.1.4), if an LED replacement bulb is fitted and there is no sticker, the sticker cannot be read, it looks like it has been tampered with, or it clearly does not match the bulb. The change does not apply to motorcycles (class 1 and 2), to halogen headlamps converted to HID bulbs, or to full LED headlamp units fitted in place of the original ones. The notice applies to MOTs in England, Scotland and Wales. Read GOV.UK: MOT special notice 05-26 (LED replacement bulbs).

There are different MOT rules and processes for vehicles registered in Northern Ireland. Defect details are not provided for Northern Ireland tests. Our Northern Ireland guide explains what an NI MOT check shows.

Things that will not fail an MOT on their own

Some things are not checked at all, and some faults are only minor or not a defect.

The MOT is not the same as a service and does not check the vehicle's general mechanical condition. It does not cover the condition of the engine, clutch or gearbox.
Spare wheels and tyres are not inspected.
Windscreen damage that does not affect the driver’s view is a minor defect, so it does not fail on its own.
A slight seepage that leaves a film of fluid on a shock absorber is not a reason to fail.
A leak of engine coolant, screen wash or the fluid for selective catalytic reduction is not a reason to fail.
A passenger airbag that is switched off is not a defect, and nor is a light showing that it is switched off.
A brake fluid warning light that is on or faulty is a minor defect.
A tyre pressure warning light can stay on after an earlier loss of pressure. If it is not clear that it shows a fault, the tester adds an advisory instead.

Common motorbike MOT failures

In DVSA’s figures for motorcycles (classes 1 and 2), April 2025 to March 2026, the areas with the most failure defects were lamps and reflectors (40.74%), brakes (18.25%), structure and attachments (11.23%), suspension (10.20%) and tyres (8.84%). 13.40% of motorcycle tests failed as the vehicle was brought in.

Source: GOV.UK: MOT testing data for Great Britain (DVSA), table “MOT class 1 and 2 vehicles: initial failures by defect category (DVSA/MOT/02)”. Last checked 25 October 2026.

For every fault that fails a motorcycle, read GOV.UK: MOT inspection manual for motorcycles or GOV.UK: Motorcycle parts checked at an MOT.

Check what your vehicle failed on before

Enter your number plate below to see every past fail and advisory in the official record, with the tester’s exact wording.

Before the test, use our pre-MOT checklist to check these things yourself. If your vehicle fails, our MOT retest guide explains free and partial retests.

Frequently asked questions

What fails an MOT?

Your vehicle fails its MOT if the test result lists any dangerous or major problems. Minor problems and advisories do not cause a fail. In DVSA’s figures for cars and light vans up to 3,000kg (classes 3 and 4), April 2025 to March 2026, the most common failure areas were lamps, reflectors and electrical equipment (24.89% of failure defects), suspension (20.49%) and brakes (15.18%).

What are the most common MOT failures?

Do warning lights fail an MOT?

Yes, some do. The MOT inspection manual lists these as failures. The engine warning light (malfunction indicator lamp) not working or showing a fault, on petrol cars first used from 1 July 2003 and diesel cars from 1 July 2008: major. The ABS warning light not working or showing a fault: major. The airbag (SRS) warning light showing a fault: major. The stability control (ESC) warning light showing a fault: major. The electronic power steering or electronic parking brake warning light showing a fault: major. The tyre pressure monitoring system obviously not working, on cars first used from 1 January 2012: major. A brake fluid warning light that is on or faulty is a minor defect.

Will LED headlight bulbs fail an MOT?

Not if they are approved and have a matching sticker. From 14 October 2026, MOT testers must accept ECE approved LED replacement (LEDr) bulbs in existing halogen headlamps on class 3, 4, 5 and 7 vehicles. The bulb must have a matching approval sticker from its manufacturer, fixed permanently to the vehicle where the tester can see it. The tester only checks that the sticker is there; they do not remove the lamp or the bulb. The headlamp fails, as a major defect (“light source and lamp not compatible”, section 4.1.4), if an LED replacement bulb is fitted and there is no sticker, the sticker cannot be read, it looks like it has been tampered with, or it clearly does not match the bulb. The change does not apply to motorcycles (class 1 and 2), to halogen headlamps converted to HID bulbs, or to full LED headlamp units fitted in place of the original ones. The notice applies to MOTs in England, Scotland and Wales.

Does an advisory fail an MOT?

No. A tester can record an advisory when an item is not worn or damaged enough to fail the test. What GOV.UK says about an advisory: It could become more serious in the future. Monitor it and repair it if necessary.

Can a car fail its MOT on tyres?

Yes. Tread depth below the legal limit (for cars, 1.6mm across the central three-quarters of the tread): dangerous. A cut deep enough to reach the ply or cords: major. A lump, bulge or tear, or cords showing: dangerous. Tyres had 12.94% of all failure defects on cars and light vans in DVSA’s figures for April 2025 to March 2026.

What Fails an MOT?

Quick answers