MOT advisories that most often mean the car is never tested again
Last updated · OBDCode UK editorial
Among MOT advisories with at least 20,000 cars in the 2024 pass cohort, “Chassis condition or chassis corroded within 30cm of a mounting, but not seriously affecting overall security” had the largest gap in the rate of not being tested again in 2025: 20.5 percentage points above cars without that advisory (31,566 cars; 27.8% (95% CI 27.3–28.3) versus 7.2% (95% CI 7.2–7.3)).
Ranked by the percentage-point gap in the 2025 not-tested rate versus cars that passed without the advisory. Advisories with fewer than 20,000 cars are excluded.
The ranking
Scroll horizontally to read every ranking column.
| Rank | Certificate wording | System | Not-tested gap | Gone rate vs control | Cars |
|---|---|---|---|---|---|
| 1 | Chassis condition or chassis corroded within 30cm of a mounting, but not seriously affecting overall security | Body, chassis, structure | +20.5 pp | 27.8% (95% CI 27.3–28.3) vs 7.2% (95% CI 7.2–7.3) | 31,566 |
| 2 | Integral vehicle structure condition is corroded but structural rigidity is not significantly reduced | Body, chassis, structure | +19.6 pp | 26.8% (95% CI 26.5–27.1) vs 7.2% (95% CI 7.2–7.2) | 74,771 |
| 3 | Chassis condition is corroded but structural rigidity is not significantly reduced | Body, chassis, structure | +17.6 pp | 24.8% (95% CI 24.5–25.1) vs 7.2% (95% CI 7.2–7.2) | 69,801 |
| 4 | Sub-frame mounting prescribed areas prescribed area is corroded but not considered excessive | Suspension | +15.2 pp | 22.4% (95% CI 22.0–22.8) vs 7.2% (95% CI 7.2–7.3) | 46,414 |
| 5 | Parking brake efficiency (Trikes, quads and pre-68 vehicles) efficiency only just met. It would appear that the braking system requires adjustment or repair. | Brakes | +14.9 pp | 22.1% (95% CI 21.7–22.5) vs 7.2% (95% CI 7.2–7.3) | 50,658 |
| 6 | Component mounting prescribed areas prescribed area is corroded but not considered excessive | Suspension | +14.7 pp | 21.9% (95% CI 21.7–22.2) vs 7.2% (95% CI 7.2–7.2) | 107,819 |
| 7 | Other suspension component corroded but not seriously weakened | Suspension | +13.6 pp | 20.8% (95% CI 20.5–21.1) vs 7.2% (95% CI 7.2–7.3) | 55,330 |
| 8 | Headlamp has a product on the lens but not seriously reducing light output | Lamps, reflectors and electrical equipment | +13.5 pp | 20.7% (95% CI 20.5–20.9) vs 7.2% (95% CI 7.2–7.2) | 151,411 |
| 9 | Engine oil leaks leak, but not excessive | Noise, emissions and leaks | +13.4 pp | 20.2% (95% CI 20.1–20.3) vs 6.8% (95% CI 6.8–6.8) | 831,419 |
| 10 | Flexible brake hoses slightly deteriorated | Brakes | +12.0 pp | 19.3% (95% CI 18.9–19.6) vs 7.2% (95% CI 7.2–7.3) | 57,008 |
| 11 | Wheel bearings has slight play | Suspension | +11.8 pp | 19.0% (95% CI 18.8–19.3) vs 7.2% (95% CI 7.2–7.2) | 95,742 |
| 12 | Non-component advisories Fuel Pipe/s corroded | Non-component advisories | +11.6 pp | 18.9% (95% CI 18.5–19.3) vs 7.3% (95% CI 7.2–7.3) | 33,464 |
| 13 | Shock absorbers has a reduced damping effect | Suspension | +11.4 pp | 18.7% (95% CI 18.3–19.0) vs 7.3% (95% CI 7.2–7.3) | 45,193 |
| 14 | Sub-frame condition is corroded but structural rigidity is not significantly reduced | Body, chassis, structure | +11.4 pp | 18.7% (95% CI 18.1–19.2) vs 7.3% (95% CI 7.3–7.3) | 22,273 |
| 15 | Steering rack has slight free play detected at steering wheel | Steering | +10.9 pp | 18.1% (95% CI 17.7–18.6) vs 7.3% (95% CI 7.3–7.3) | 27,995 |
| 16 | Exhaust system has a minor leak of exhaust gases | Body, chassis, structure | +10.8 pp | 17.9% (95% CI 17.8–18.0) vs 7.1% (95% CI 7.1–7.1) | 373,802 |
| 17 | Track rod end ball joint has slight play | Steering | +9.9 pp | 17.1% (95% CI 16.9–17.2) vs 7.2% (95% CI 7.2–7.2) | 234,897 |
| 18 | Wheel bearings slightly noisy | Suspension | +9.6 pp | 16.8% (95% CI 16.5–17.1) vs 7.2% (95% CI 7.2–7.3) | 67,766 |
| 19 | Sub-frame corroded but not seriously weakened | Suspension | +9.3 pp | 16.4% (95% CI 16.3–16.5) vs 7.1% (95% CI 7.1–7.1) | 364,836 |
| 20 | Ball joint has slight play | Suspension | +9.2 pp | 16.4% (95% CI 16.2–16.5) vs 7.1% (95% CI 7.1–7.1) | 411,708 |
| 21 | Linkage ball joints ball joint has slight play | Suspension | +8.9 pp | 16.1% (95% CI 16.0–16.3) vs 7.2% (95% CI 7.2–7.2) | 247,306 |
| 22 | Rigid brake pipes corroded, covered in grease or other material | Brakes | +8.3 pp | 15.4% (95% CI 15.3–15.5) vs 7.0% (95% CI 7.0–7.0) | 690,642 |
| 23 | Non-component advisories Play in steering rack inner joint(s) | Non-component advisories | +8.1 pp | 15.3% (95% CI 15.1–15.4) vs 7.2% (95% CI 7.2–7.2) | 241,394 |
| 24 | Anti-roll bar corroded but not seriously weakened | Suspension | +8.0 pp | 15.2% (95% CI 14.8–15.6) vs 7.3% (95% CI 7.3–7.3) | 29,333 |
| 25 | Non-component advisories Coolant leak | Non-component advisories | +7.7 pp | 14.9% (95% CI 14.6–15.3) vs 7.3% (95% CI 7.3–7.3) | 35,882 |
| 26 | Transmission oil leaks leak, but not excessive | Noise, emissions and leaks | +7.5 pp | 14.8% (95% CI 14.6–15.0) vs 7.2% (95% CI 7.2–7.2) | 110,031 |
| 27 | Coil spring corroded | Suspension | +7.2 pp | 14.3% (95% CI 14.2–14.4) vs 7.1% (95% CI 7.1–7.1) | 587,235 |
| 28 | Suspension arm corroded but not seriously weakened | Suspension | +7.0 pp | 14.2% (95% CI 14.0–14.3) vs 7.2% (95% CI 7.2–7.2) | 209,642 |
| 29 | Shock absorbers has slight external damage to the casing | Suspension | +6.8 pp | 14.1% (95% CI 13.8–14.4) vs 7.3% (95% CI 7.2–7.3) | 48,395 |
| 30 | Swivel pins and bushes swivel pin and/or bush slightly worn | Suspension | +6.8 pp | 14.1% (95% CI 13.8–14.3) vs 7.2% (95% CI 7.2–7.3) | 86,437 |
| 31 | Linkage pins and bushes pin or bush worn but not resulting in excessive movement | Suspension | +6.4 pp | 13.7% (95% CI 13.4–13.9) vs 7.3% (95% CI 7.2–7.3) | 80,908 |
| 32 | Flexible brake hoses has slight corrosion to ferrule | Brakes | +6.3 pp | 13.5% (95% CI 13.3–13.7) vs 7.2% (95% CI 7.2–7.2) | 138,431 |
| 33 | Individual direction indicators slightly discoloured | Lamps, reflectors and electrical equipment | +6.2 pp | 13.4% (95% CI 13.2–13.6) vs 7.2% (95% CI 7.2–7.2) | 142,389 |
| 34 | Registration plates deteriorated but not likely to be misread | Identification of the vehicle | +5.9 pp | 13.0% (95% CI 13.0–13.1) vs 7.2% (95% CI 7.1–7.2) | 466,754 |
| 35 | Pedal wearing smooth | Brakes | +5.9 pp | 13.1% (95% CI 12.8–13.6) vs 7.3% (95% CI 7.3–7.3) | 27,507 |
| 36 | Exhaust system mounting defective | Body, chassis, structure | +5.9 pp | 13.1% (95% CI 12.9–13.3) vs 7.2% (95% CI 7.2–7.2) | 146,325 |
| 37 | Pins and bushes pin or bush slightly worn | Suspension | +5.8 pp | 13.1% (95% CI 12.7–13.5) vs 7.3% (95% CI 7.3–7.3) | 23,076 |
| 38 | Shock absorbers has a slightly worn bush | Suspension | +5.5 pp | 12.7% (95% CI 12.5–13.0) vs 7.3% (95% CI 7.2–7.3) | 65,124 |
| 39 | Pins and bushes pin or bush worn but not resulting in excessive movement | Suspension | +5.1 pp | 12.1% (95% CI 12.0–12.2) vs 7.0% (95% CI 7.0–7.0) | 1,188,355 |
| 40 | Non-obligatory stop lamp not working | Lamps, reflectors and electrical equipment | +4.8 pp | 12.1% (95% CI 11.8–12.3) vs 7.3% (95% CI 7.3–7.3) | 54,730 |
| 41 | Service brake imbalance requirements only just met. It would appear that the braking system requires adjustment or repair. | Brakes | +4.7 pp | 11.9% (95% CI 11.7–12.2) vs 7.3% (95% CI 7.3–7.3) | 50,588 |
| 42 | Service brake performance binding but not excessively | Brakes | +4.3 pp | 11.5% (95% CI 11.4–11.6) vs 7.2% (95% CI 7.2–7.2) | 316,800 |
| 43 | Macpherson strut corroded but not seriously weakened | Suspension | +4.3 pp | 11.5% (95% CI 11.2–11.9) vs 7.3% (95% CI 7.3–7.3) | 31,467 |
| 44 | Shock absorbers has light misting of oil | Suspension | +3.7 pp | 10.8% (95% CI 10.8–10.9) vs 7.2% (95% CI 7.2–7.2) | 631,357 |
| 45 | Service brake performance fluctuating, but not excessively | Brakes | +2.6 pp | 9.8% (95% CI 9.6–10.0) vs 7.3% (95% CI 7.3–7.3) | 115,705 |
| 46 | Brake discs worn, pitted or scored, but not seriously weakened | Brakes | +2.4 pp | 9.5% (95% CI 9.5–9.6) vs 7.1% (95% CI 7.1–7.1) | 1,777,480 |
| 47 | Tread depth worn close to legal limit/worn on edge | Tyres | +2.0 pp | 8.9% (95% CI 8.9–9.0) vs 7.0% (95% CI 7.0–7.0) | 3,822,709 |
| 48 | Condition slightly distorted | Road Wheels | +1.1 pp | 8.4% (95% CI 8.2–8.5) vs 7.3% (95% CI 7.3–7.3) | 163,219 |
| 49 | Brake discs worn, but not excessively | Brakes | +0.8 pp | 8.1% (95% CI 8.0–8.2) vs 7.3% (95% CI 7.2–7.3) | 502,155 |
| 50 | Brake pads wearing thin | Brakes | +0.6 pp | 7.8% (95% CI 7.8–7.8) vs 7.2% (95% CI 7.2–7.2) | 1,724,201 |
| 51 | Condition slightly damaged | Tyres | -0.6 pp | 6.7% (95% CI 6.6–6.8) vs 7.3% (95% CI 7.3–7.3) | 155,933 |
| 52 | Condition slightly damaged/cracking or perishing | Tyres | -1.0 pp | 6.3% (95% CI 6.3–6.3) vs 7.4% (95% CI 7.3–7.4) | 1,939,529 |
| 53 | Non-component advisories Nail in tyre | Non-component advisories | -1.8 pp | 5.5% (95% CI 5.5–5.6) vs 7.3% (95% CI 7.3–7.3) | 360,247 |
| 54 | Condition has a cut but not deep enough to reach the ply or cords | Tyres | -1.8 pp | 5.5% (95% CI 5.4–5.6) vs 7.3% (95% CI 7.3–7.3) | 301,660 |
| 55 | Non-component advisories Child Seat fitted not allowing full inspection of adult belt | Non-component advisories | -1.8 pp | 5.5% (95% CI 5.4–5.6) vs 7.3% (95% CI 7.3–7.3) | 433,540 |
| 56 | Non-component advisories Vehicles internal headlight adjuster altered to recheck lights | Non-component advisories | -2.0 pp | 5.2% (95% CI 5.0–5.5) vs 7.3% (95% CI 7.3–7.3) | 38,870 |
| 57 | Non-component advisories Items removed from driver's view prior to test | Non-component advisories | -2.1 pp | 5.2% (95% CI 5.1–5.3) vs 7.3% (95% CI 7.3–7.3) | 137,470 |
How this ranking is calculated
- Universe. Class 4 vehicles whose first 2024 normal test was a pass (P or PRS) and carried this advisory wording.
- 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 all other 2024 passes. 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. Advisory 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. 57 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 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 failures that most often mean the car is never tested againLargest 2025 not-tested gap versus cars that did not fail on that line
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.