MOT failures that most often mean the car is never tested again
Last updated · OBDCode UK editorial
Among MOT failures with at least 20,000 cars in the 2024 fail cohort, “Prescribed areas prescribed area is corroded but not considered excessive” had the largest gap in the rate of not being tested again in 2025: 29.1 percentage points above cars that did not fail on that line (58,367 cars; 37.7% (95% CI 37.3–38.1) versus 8.6% (95% CI 8.6–8.6)).
Ranked by the percentage-point gap in the 2025 not-tested rate versus cars whose 2024 index test did not fail on that line. Failures with fewer than 20,000 cars are excluded.
By fuel at the 2024 test
Petrol and diesel are different faults. Each row is that fuel only. It is not the all-fuels same-item rate already on this page. The not-tested gap is percentage points versus other cars of the same fuel that did not fail on this wording.
Scroll horizontally to read every fuel column.
| Fuel | Cars | Same-item fail | Not-tested gap |
|---|---|---|---|
| Petrol | 192,397 | 15.4% (95% CI 15.3–15.6) | +15.6 pp |
| Diesel | 194,460 | 14.2% (95% CI 14.1–14.4) | +6.9 pp |
| Hybrid Electric (Clean) | 1,972 | 9.0% (95% CI 7.8–10.4) | +4.1 pp |
The ranking
Scroll horizontally to read every ranking column.
| Rank | Certificate wording | System | Not-tested gap | Gone rate vs control | Cars |
|---|---|---|---|---|---|
| 1 | Prescribed areas prescribed area is corroded but not considered excessive | Seat Belts and Supplementary Restraint Systems | +29.1 pp | 37.7% (95% CI 37.3–38.1) vs 8.6% (95% CI 8.6–8.6) | 58,367 |
| 2 | Chassis condition or chassis corroded within 30cm of a mounting, but not seriously affecting overall security | Body, chassis, structure | +28.5 pp | 37.1% (95% CI 36.6–37.6) vs 8.6% (95% CI 8.6–8.7) | 38,417 |
| 3 | Chassis condition is corroded but structural rigidity is not significantly reduced | Body, chassis, structure | +28.4 pp | 37.0% (95% CI 36.4–37.7) vs 8.7% (95% CI 8.6–8.7) | 22,841 |
| 4 | Integral vehicle structure condition is corroded but structural rigidity is not significantly reduced | Body, chassis, structure | +27.9 pp | 36.5% (95% CI 36.1–37.0) vs 8.6% (95% CI 8.6–8.6) | 49,559 |
| 5 | Component mounting prescribed areas prescribed area is corroded but not considered excessive | Suspension | +25.7 pp | 34.2% (95% CI 34.0–34.5) vs 8.5% (95% CI 8.5–8.6) | 159,224 |
| 6 | Battery(ies) A battery insecure and likely to fall from carrier or cause a short circuit | Lamps, reflectors and electrical equipment | +23.4 pp | 32.1% (95% CI 31.5–32.6) vs 8.7% (95% CI 8.6–8.7) | 23,805 |
| 7 | Engine oil leaks leak, but not excessive | Noise, emissions and leaks | +22.7 pp | 31.3% (95% CI 30.9–31.8) vs 8.6% (95% CI 8.6–8.7) | 38,080 |
| 8 | Sub-frame corroded but not seriously weakened | Suspension | +22.2 pp | 30.9% (95% CI 30.4–31.4) vs 8.7% (95% CI 8.6–8.7) | 35,497 |
| 9 | Pre 01/07/2008 Turbo Smoke opacity levels exceed the manufacturer's specified limit | Noise, emissions and leaks | +19.1 pp | 27.8% (95% CI 27.2–28.4) vs 8.7% (95% CI 8.7–8.7) | 20,637 |
| 10 | Flexible brake hoses has slight corrosion to ferrule | Brakes | +18.8 pp | 27.5% (95% CI 26.9–28.0) vs 8.7% (95% CI 8.7–8.7) | 23,598 |
| 11 | Catalyst emissions Emissions levels exceed default limits | Noise, emissions and leaks | +18.7 pp | 27.3% (95% CI 27.0–27.6) vs 8.6% (95% CI 8.6–8.6) | 82,254 |
| 12 | Headlamp reflector or lens seriously defective or missing | Lamps, reflectors and electrical equipment | +18.6 pp | 27.3% (95% CI 26.9–27.7) vs 8.6% (95% CI 8.6–8.7) | 47,290 |
| 13 | Catalyst emissions Emissions levels exceed the manufacturer's specified limits | Noise, emissions and leaks | +18.5 pp | 27.1% (95% CI 26.8–27.5) vs 8.6% (95% CI 8.6–8.6) | 73,521 |
| 14 | Emissions not tested Emissions test unable to be completed | Noise, emissions and leaks | +18.5 pp | 27.1% (95% CI 26.8–27.3) vs 8.6% (95% CI 8.6–8.6) | 132,012 |
| 15 | Headlamp has a product on the lens but not seriously reducing light output | Lamps, reflectors and electrical equipment | +18.3 pp | 26.9% (95% CI 26.5–27.3) vs 8.7% (95% CI 8.6–8.7) | 41,531 |
| 16 | Suspension arm corroded but not seriously weakened | Suspension | +17.2 pp | 25.8% (95% CI 25.3–26.3) vs 8.7% (95% CI 8.6–8.7) | 31,833 |
| 17 | Rbt (sp) Parking brake efficiency less than 50% of the required value | Brakes | +17.1 pp | 25.7% (95% CI 25.4–26.0) vs 8.6% (95% CI 8.6–8.6) | 91,651 |
| 18 | Individual direction indicators A direction indicator lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning | Lamps, reflectors and electrical equipment | +16.4 pp | 25.1% (95% CI 24.7–25.5) vs 8.6% (95% CI 8.6–8.7) | 52,165 |
| 19 | Anti-lock braking system Warning device shows system malfunction | Brakes | +16.4 pp | 25.0% (95% CI 24.7–25.2) vs 8.6% (95% CI 8.6–8.6) | 123,785 |
| 20 | Door condition A door will not open using the relevant control or close properly | Body, chassis, structure | +15.5 pp | 24.1% (95% CI 23.8–24.5) vs 8.7% (95% CI 8.6–8.7) | 51,168 |
| 21 | Wheel bearings has slight play | Suspension | +15.4 pp | 24.1% (95% CI 23.7–24.4) vs 8.7% (95% CI 8.6–8.7) | 49,396 |
| 22 | Stop lamps all missing or inoperative | Lamps, reflectors and electrical equipment | +15.2 pp | 23.8% (95% CI 23.3–24.4) vs 8.7% (95% CI 8.7–8.7) | 24,603 |
| 23 | Rigid brake pipes Leaking brake pipe or connection on a hydraulic system | Brakes | +15.1 pp | 23.8% (95% CI 23.3–24.3) vs 8.7% (95% CI 8.7–8.7) | 30,094 |
| 24 | Exhaust system has a minor leak of exhaust gases | Exhaust, Fuel and Emissions | +14.4 pp | 23.0% (95% CI 22.8–23.1) vs 8.6% (95% CI 8.6–8.6) | 241,756 |
| 25 | Headlamp emitted colour, position or intensity not in accordance with the requirements | Lamps, reflectors and electrical equipment | +14.4 pp | 23.0% (95% CI 22.6–23.5) vs 8.7% (95% CI 8.7–8.7) | 32,413 |
| 26 | Steering rack gaiter or ball joint dust cover missing or no longer prevents the ingress of dirt etc | Steering | +14.2 pp | 22.9% (95% CI 22.6–23.2) vs 8.6% (95% CI 8.6–8.7) | 68,143 |
| 27 | Shock absorbers has a reduced damping effect | Suspension | +14.0 pp | 22.7% (95% CI 22.3–23.2) vs 8.7% (95% CI 8.7–8.7) | 32,295 |
| 28 | Catalyst emissions An induction or exhaust leak that could affect emissions levels | Noise, emissions and leaks | +14.0 pp | 22.7% (95% CI 22.2–23.1) vs 8.7% (95% CI 8.6–8.7) | 38,770 |
| 29 | SRS Malfunction Indicator Lamp warning lamp does not illuminate | Seat Belts and Supplementary Restraint Systems | +14.0 pp | 22.6% (95% CI 22.3–22.8) vs 8.6% (95% CI 8.6–8.6) | 130,095 |
| 30 | Mirrors Obligatory mirror or device inoperative, excessively damaged or insecure | Visibility | +13.9 pp | 22.6% (95% CI 22.1–23.0) vs 8.7% (95% CI 8.7–8.7) | 28,484 |
| 31 | Ball joint A suspension pin, bush or joint likely to become detached | Suspension | +13.8 pp | 22.5% (95% CI 22.1–23.0) vs 8.7% (95% CI 8.7–8.7) | 33,061 |
| 32 | Headlamp Lamp not securely attached | Lamps, reflectors and electrical equipment | +13.8 pp | 22.5% (95% CI 22.1–22.9) vs 8.7% (95% CI 8.6–8.7) | 46,099 |
| 33 | Rigid brake pipes corroded, covered in grease or other material | Brakes | +13.8 pp | 22.4% (95% CI 22.2–22.5) vs 8.6% (95% CI 8.6–8.6) | 199,907 |
| 34 | Catalyst emissions Lambda coefficient outside the default limits or the range specified by the manufacturer | Noise, emissions and leaks | +13.4 pp | 22.0% (95% CI 21.8–22.2) vs 8.6% (95% CI 8.6–8.6) | 166,607 |
| 35 | Brake performance not tested Brake performance unable to be tested | Brakes | +13.4 pp | 22.0% (95% CI 21.7–22.4) vs 8.7% (95% CI 8.6–8.7) | 53,394 |
| 36 | Linkage pins and bushes pin or bush worn but not resulting in excessive movement | Suspension | +13.4 pp | 22.0% (95% CI 21.6–22.5) vs 8.7% (95% CI 8.7–8.7) | 31,187 |
| 37 | Service brake performance Service brake efficiency below minimum requirement | Brakes | +13.3 pp | 22.0% (95% CI 21.7–22.3) vs 8.7% (95% CI 8.6–8.7) | 56,819 |
| 38 | Size/type Tyres on the same axle or on twin wheels are different sizes | Tyres | +13.2 pp | 21.9% (95% CI 21.4–22.3) vs 8.7% (95% CI 8.7–8.7) | 35,837 |
| 39 | Parking brake performance Parking brake inoperative on one side | Brakes | +13.0 pp | 21.7% (95% CI 21.5–21.9) vs 8.6% (95% CI 8.6–8.6) | 167,276 |
| 40 | Track rod end A steering ball joint worn to the extent there is a serious risk of detachment | Steering | +13.0 pp | 21.6% (95% CI 21.1–22.2) vs 8.7% (95% CI 8.7–8.7) | 22,161 |
| 41 | Service brake imbalance Brakes imbalance across an axle such that the braking effort from any wheel is less than 70% of the maximum effort recorded from the other wheel on the same axle. | Brakes | +12.9 pp | 21.5% (95% CI 21.3–21.7) vs 8.6% (95% CI 8.6–8.6) | 112,629 |
| 42 | Position lamp A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning | Lamps, reflectors and electrical equipment | +12.9 pp | 21.3% (95% CI 21.2–21.4) vs 8.4% (95% CI 8.4–8.5) | 565,083 |
| 43 | Registration plate lamp(s) Rear registration plate lamp does not illuminate simultaneously with the position lamps | Lamps, reflectors and electrical equipment | +12.8 pp | 21.4% (95% CI 21.0–21.9) vs 8.7% (95% CI 8.7–8.7) | 33,185 |
| 44 | Rbt (sp) Parking brake efficiency below minimum requirement | Brakes | +12.6 pp | 21.1% (95% CI 21.0–21.2) vs 8.5% (95% CI 8.5–8.5) | 356,618 |
| 45 | Horn Audible warning inoperative | Lamps, reflectors and electrical equipment | +12.5 pp | 21.1% (95% CI 20.9–21.4) vs 8.6% (95% CI 8.6–8.7) | 88,092 |
| 46 | Headlamp aim The aim of a headlamp is not within limits laid down in the requirements | Lamps, reflectors and electrical equipment | +12.4 pp | 20.9% (95% CI 20.7–21.0) vs 8.5% (95% CI 8.4–8.5) | 553,422 |
| 47 | Registration plates deteriorated but not likely to be misread | Identification of the vehicle | +12.4 pp | 21.0% (95% CI 20.6–21.4) vs 8.7% (95% CI 8.7–8.7) | 37,629 |
| 48 | Wheel bearings slightly noisy | Suspension | +12.2 pp | 20.8% (95% CI 20.6–21.1) vs 8.6% (95% CI 8.6–8.6) | 91,899 |
| 49 | Individual direction indicators slightly discoloured | Lamps, reflectors and electrical equipment | +12.1 pp | 20.7% (95% CI 20.4–20.9) vs 8.6% (95% CI 8.6–8.6) | 102,004 |
| 50 | Fuel cap/sealing device Fuel system leaking, or missing or ineffective filler cap | Body, chassis, structure | +12.0 pp | 20.7% (95% CI 20.2–21.2) vs 8.7% (95% CI 8.7–8.7) | 28,902 |
| 51 | Exhaust system mounting defective | Body, chassis, structure | +11.8 pp | 20.4% (95% CI 20.1–20.7) vs 8.6% (95% CI 8.6–8.7) | 80,378 |
| 52 | Linkage ball joints ball joint has slight play | Suspension | +11.8 pp | 20.4% (95% CI 20.2–20.5) vs 8.6% (95% CI 8.6–8.6) | 218,778 |
| 53 | Registration plate lamp(s) A rear registration plate lamp or light source missing or inoperative in the case of multiple lamps or light sources | Lamps, reflectors and electrical equipment | +11.6 pp | 20.2% (95% CI 20.1–20.4) vs 8.6% (95% CI 8.6–8.6) | 246,610 |
| 54 | An obligatory rear fog lamp missing, or a front or rear fog lamp inoperative or in the case of a multiple light source more than 1/2 not functioning | Lamps, reflectors and electrical equipment | +11.6 pp | 20.2% (95% CI 20.0–20.4) vs 8.6% (95% CI 8.6–8.6) | 124,834 |
| 55 | Malfunction indicator lamp Engine MIL illuminated indicating a malfunction | Noise, emissions and leaks | +11.5 pp | 20.0% (95% CI 19.9–20.1) vs 8.5% (95% CI 8.5–8.5) | 391,384 all fuels |
| 56 | Attachment A wheel with a loose or missing wheel nut, bolt or stud | Road Wheels | +11.4 pp | 20.0% (95% CI 19.7–20.3) vs 8.7% (95% CI 8.6–8.7) | 68,581 |
| 57 | Stop lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning | Lamps, reflectors and electrical equipment | +10.8 pp | 19.3% (95% CI 19.2–19.4) vs 8.5% (95% CI 8.5–8.6) | 395,913 |
| 58 | Swivel pins and bushes swivel pin and/or bush slightly worn | Suspension | +10.7 pp | 19.4% (95% CI 19.0–19.9) vs 8.7% (95% CI 8.7–8.7) | 30,660 |
| 59 | A headlamp or light source missing, inoperative or more than ½ not functioning in the case of LED | Lamps, reflectors and electrical equipment | +10.6 pp | 19.1% (95% CI 19.0–19.3) vs 8.6% (95% CI 8.6–8.6) | 339,320 |
| 60 | Condition Seat belt not functioning as intended or of an incorrect type | Seat belts and supplementary restraint systems | +10.4 pp | 19.1% (95% CI 18.6–19.6) vs 8.7% (95% CI 8.7–8.7) | 23,774 |
| 61 | Electronic stability control warning lamp not working | Brakes | +10.4 pp | 19.1% (95% CI 18.8–19.4) vs 8.7% (95% CI 8.6–8.7) | 60,979 |
| 62 | Macpherson strut A suspension pin, bush, joint or bearing excessively worn | Suspension | +10.3 pp | 19.0% (95% CI 18.5–19.4) vs 8.7% (95% CI 8.7–8.7) | 26,821 |
| 63 | Headlamp aim not tested Headlamp aim unable to be tested | Lamps, reflectors and electrical equipment | +10.2 pp | 18.8% (95% CI 18.6–19.1) vs 8.6% (95% CI 8.6–8.7) | 87,360 |
| 64 | On or after 01/07/2008 Smoke opacity levels exceed the manufacturer's specified limit | Noise, emissions and leaks | +10.1 pp | 18.7% (95% CI 18.3–19.1) vs 8.7% (95% CI 8.7–8.7) | 36,817 |
| 65 | Hand lever A service brake control has insufficient reserve travel | Brakes | +9.9 pp | 18.6% (95% CI 18.2–19.0) vs 8.7% (95% CI 8.7–8.7) | 38,959 |
| 66 | Joints A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc | Body, chassis, structure | +9.9 pp | 18.4% (95% CI 18.3–18.6) vs 8.5% (95% CI 8.5–8.5) | 432,660 |
| 67 | Windscreen washers not working or not providing sufficient fluid to clear the windscreen | Visibility | +9.6 pp | 18.1% (95% CI 18.0–18.2) vs 8.5% (95% CI 8.5–8.5) | 502,334 |
| 68 | Parking brake lever has excessive movement indicating incorrect adjustment | Brakes | +9.4 pp | 18.0% (95% CI 17.7–18.3) vs 8.7% (95% CI 8.6–8.7) | 61,073 |
| 69 | Service brake imbalance requirements only just met. It would appear that the braking system requires adjustment or repair. | Brakes | +9.3 pp | 17.9% (95% CI 17.6–18.2) vs 8.7% (95% CI 8.6–8.7) | 60,130 |
| 70 | Condition Seat belt buckle missing, damaged or not functioning as intended | Seat belts and supplementary restraint systems | +9.1 pp | 17.8% (95% CI 17.4–18.2) vs 8.7% (95% CI 8.7–8.7) | 38,700 |
| 71 | Headlamp levelling device inoperative | Lamps, reflectors and electrical equipment | +9.1 pp | 17.8% (95% CI 17.4–18.2) vs 8.7% (95% CI 8.7–8.7) | 39,066 |
| 72 | Track rod end ball joint has slight play | Steering | +9.1 pp | 17.6% (95% CI 17.5–17.8) vs 8.6% (95% CI 8.6–8.6) | 350,028 |
| 73 | Service brake performance Abnormal lag in brake operation on a wheel | Brakes | +8.9 pp | 17.6% (95% CI 17.2–18.0) vs 8.7% (95% CI 8.7–8.7) | 31,845 |
| 74 | Service brake performance binding but not excessively | Brakes | +8.7 pp | 17.3% (95% CI 17.2–17.4) vs 8.6% (95% CI 8.6–8.6) | 286,992 |
| 75 | An obstruction significantly affecting the driver's view of the road through the swept area of the windscreen or an obligatory external mirror not visible | Visibility | +8.7 pp | 17.3% (95% CI 16.8–17.9) vs 8.7% (95% CI 8.7–8.7) | 20,653 |
| 76 | Pins and bushes pin or bush worn but not resulting in excessive movement | Suspension | +8.7 pp | 17.2% (95% CI 17.1–17.3) vs 8.6% (95% CI 8.5–8.6) | 449,260 |
| 77 | Ball joint has slight play | Suspension | +8.5 pp | 17.0% (95% CI 16.9–17.1) vs 8.5% (95% CI 8.5–8.5) | 564,288 |
| 78 | Pins and bushes A suspension pin, bush or joint likely to become detached | Suspension | +8.2 pp | 16.9% (95% CI 16.3–17.4) vs 8.7% (95% CI 8.7–8.7) | 20,841 |
| 79 | Shock absorbers has light misting of oil | Suspension | +7.9 pp | 16.5% (95% CI 16.4–16.7) vs 8.6% (95% CI 8.6–8.6) | 266,788 |
| 80 | Ball joint dust cover A suspension joint dust cover missing or no longer prevents the ingress of dirt etc | Suspension | +7.9 pp | 16.5% (95% CI 16.3–16.6) vs 8.6% (95% CI 8.6–8.6) | 251,775 |
| 81 | Linkage ball joint dust cover A suspension joint dust cover missing or no longer prevents the ingress of dirt etc | Suspension | +7.8 pp | 16.4% (95% CI 16.2–16.5) vs 8.6% (95% CI 8.6–8.6) | 223,930 |
| 82 | Brake discs worn, pitted or scored, but not seriously weakened | Brakes | +7.4 pp | 16.0% (95% CI 15.8–16.3) vs 8.7% (95% CI 8.6–8.7) | 76,299 |
| 83 | Service brake performance fluctuating, but not excessively | Brakes | +7.2 pp | 15.8% (95% CI 15.6–16.0) vs 8.7% (95% CI 8.6–8.7) | 99,151 |
| 84 | Side repeaters A direction indicator lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning | Lamps, reflectors and electrical equipment | +6.4 pp | 15.1% (95% CI 14.9–15.2) vs 8.7% (95% CI 8.6–8.7) | 125,571 |
| 85 | Shock absorbers has a slightly worn bush | Suspension | +6.3 pp | 15.0% (95% CI 14.6–15.3) vs 8.7% (95% CI 8.7–8.7) | 43,168 |
| 86 | Tread depth worn close to legal limit/worn on edge | Tyres | +5.8 pp | 14.3% (95% CI 14.2–14.4) vs 8.5% (95% CI 8.5–8.5) | 767,114 |
| 87 | Brake discs worn, but not excessively | Brakes | +5.3 pp | 14.0% (95% CI 13.8–14.1) vs 8.6% (95% CI 8.6–8.7) | 189,700 |
| 88 | Coil spring A spring or spring component fractured or seriously weakened | Suspension | +5.2 pp | 13.7% (95% CI 13.6–13.8) vs 8.6% (95% CI 8.6–8.6) | 654,624 |
| 89 | Wipers Wiper blade missing or obviously not clearing the windscreen | Visibility | +5.1 pp | 13.7% (95% CI 13.6–13.8) vs 8.6% (95% CI 8.6–8.6) | 482,354 |
| 90 | Registration plates Number plate does not conform to the specified requirements | Identification of the vehicle | +4.7 pp | 13.3% (95% CI 13.0–13.7) vs 8.7% (95% CI 8.7–8.7) | 40,838 |
| 91 | Condition A tyre cords visible or damaged | Tyres | +4.5 pp | 13.1% (95% CI 13.0–13.2) vs 8.6% (95% CI 8.6–8.6) | 449,245 |
| 92 | Condition slightly damaged/cracking or perishing | Tyres | +3.8 pp | 12.4% (95% CI 12.3–12.6) vs 8.7% (95% CI 8.6–8.7) | 178,497 |
| 93 | Reversing lamps A reversing lamp inoperative | Lamps, reflectors and electrical equipment | +3.7 pp | 12.4% (95% CI 12.1–12.8) vs 8.7% (95% CI 8.7–8.7) | 33,550 |
| 94 | Track rod end Steering rack gaiter or ball joint dust cover missing or no longer prevents the ingress of dirt etc | Steering | +3.6 pp | 12.3% (95% CI 12.1–12.5) vs 8.7% (95% CI 8.7–8.7) | 122,724 |
| 95 | Brake pads wearing thin | Brakes | +3.2 pp | 11.8% (95% CI 11.7–11.9) vs 8.6% (95% CI 8.6–8.6) | 588,405 |
| 96 | Brake pads Brake lining or pad worn down to wear indicator | Brakes | +2.6 pp | 11.3% (95% CI 11.0–11.6) vs 8.7% (95% CI 8.7–8.7) | 52,753 |
| 97 | Condition a tyre has a lump, bulge or tear caused by separation or partial failure of its structure. This includes any lifting of the tread rubber | Tyres | +1.3 pp | 10.0% (95% CI 9.7–10.2) vs 8.7% (95% CI 8.7–8.7) | 56,997 |
| 98 | Condition slightly damaged | Seat belts and supplementary restraint systems | +0.8 pp | 9.5% (95% CI 9.4–9.6) vs 8.7% (95% CI 8.7–8.7) | 153,642 |
| 99 | On or after 01/01/2014 Smoke opacity levels exceed the manufacturer's specified limit | Noise, emissions and leaks | +0.2 pp | 8.9% (95% CI 8.5–9.3) vs 8.7% (95% CI 8.7–8.7) | 20,752 |
| 100 | Condition has a cut but not deep enough to reach the ply or cords | Tyres | +0.1 pp | 8.8% (95% CI 8.7–8.9) vs 8.7% (95% CI 8.7–8.7) | 423,762 |
| 101 | A tyre pressure monitoring system malfunctioning or obviously inoperative | Tyres | -1.7 pp | 6.9% (95% CI 6.8–7.1) vs 8.7% (95% CI 8.7–8.7) | 90,173 |
How this ranking is calculated
- Universe. Class 4 vehicles whose first 2024 normal test recorded a failure on this certificate line.
- Outcome. That vehicle_id does not appear in the 2025 extract (“gone”). This is not a DVSA scrappage flag.
- Rank statistic. gone_gap_pp = (cohort gone rate − control gone rate) × 100. The control is every other Class 4 vehicle whose first 2024 normal test did not fail on this line (a car that failed on something else still belongs in the control). Highest gap is rank 1. The raw gone rate is not used to rank, because older cars vanish more often; the gap still is not a full age adjustment — age bands sit on the item page.
- Inclusion. Cohort of at least 20,000 cars.
- Ties. Larger cohort, then certificate wording A–Z.
- Censoring. A December 2024 test may not be due until 2026. Failure item pages re-run the gap on January–June 2024 tests only. Agreement with the full-year gap means the calendar window is not driving the result.
These figures are a statistical association from the national MOT extracts. They are not a prediction about an individual car, and we have not inspected any of the vehicles. 101 lines meet the inclusion rule on this page.
Other rankings
MOT advisories most likely to become a failure next yearSame-item fail rate in 2025, cohort of 20,000+
MOT advisories that most often mean the car is never tested againLargest 2025 not-tested gap versus cars without the advisory
MOT repairs that most often do not holdSame-item fail again in 2025 versus cars that did not fail on that line, cohort of 20,000+
MOT prognosis registry — method for the whole follow-up, including the vehicle_id link and the publication floor. Wilson intervals and age-standardisation: how these figures are calculated.
Source: DVSA Anonymised MOT tests and results, 2024 and 2025 extracts (Class 4). Contains public sector information licensed under the Open Government Licence v3.0. Wording is pooled across reason-for-rejection codes that print the same line on the certificate.