MOT advisories most likely to become a failure next year
Last updated · OBDCode UK editorial
Among MOT advisories with at least 20,000 cars in the 2024 pass cohort, “Track rod end ball joint has slight play” had the highest rate of the same item failing the following year: 12.7% (95% CI 12.6–12.8) of 234,897 cars — 20 times the rate for cars without it.
Ranked by same-item fail rate in 2025. Advisories with fewer than 20,000 cars in the 2024 pass cohort are excluded.
The ranking
Scroll horizontally to read every ranking column.
| Rank | Certificate wording | System | Same-item fail in 2025 | Vs cars without it | Cars |
|---|---|---|---|---|---|
| 1 | Track rod end ball joint has slight play | Steering | 12.7% (95% CI 12.6–12.8) | 20 times (0.63% (95% CI 0.6–0.6)) | 234,897 |
| 2 | Ball joint has slight play | Suspension | 9.5% (95% CI 9.4–9.6) | 8.3 times (1.1% (95% CI 1.1–1.1)) | 411,708 |
| 3 | Component mounting prescribed areas prescribed area is corroded but not considered excessive | Suspension | 7.5% (95% CI 7.4–7.7) | 27 times (0.28% (95% CI 0.3–0.3)) | 107,819 |
| 4 | Shock absorbers has light misting of oil | Suspension | 6.3% (95% CI 6.2–6.3) | 11 times (0.56% (95% CI 0.6–0.6)) | 631,357 |
| 5 | Linkage ball joints ball joint has slight play | Suspension | 5.8% (95% CI 5.8–5.9) | 15 times (0.39% (95% CI 0.4–0.4)) | 247,306 |
| 6 | Exhaust system has a minor leak of exhaust gases | Body, chassis, structure | 5.6% (95% CI 5.6–5.7) | 14 times (0.40% (95% CI 0.4–0.4)) | 373,802 |
| 7 | Shock absorbers has a slightly worn bush | Suspension | 5.6% (95% CI 5.5–5.8) | 70 times (0.08% (95% CI 0.1–0.1)) | 65,124 |
| 8 | Brake pads wearing thin | Brakes | 5.5% (95% CI 5.4–5.5) | 4.6 times (1.2% (95% CI 1.2–1.2)) | 1,724,201 |
| 9 | Rigid brake pipes corroded, covered in grease or other material | Brakes | 5.3% (95% CI 5.2–5.3) | 25 times (0.21% (95% CI 0.2–0.2)) | 690,642 |
| 10 | Pins and bushes pin or bush worn but not resulting in excessive movement | Suspension | 5.0% (95% CI 5.0–5.1) | 5.5 times (0.91% (95% CI 0.9–0.9)) | 1,188,355 |
| 11 | Wheel bearings slightly noisy | Suspension | 5.0% (95% CI 4.8–5.1) | 28 times (0.18% (95% CI 0.2–0.2)) | 67,766 |
| 12 | Individual direction indicators slightly discoloured | Lamps, reflectors and electrical equipment | 4.7% (95% CI 4.6–4.8) | 27 times (0.18% (95% CI 0.2–0.2)) | 142,389 |
| 13 | Service brake performance binding but not excessively | Brakes | 4.7% (95% CI 4.6–4.8) | 10 times (0.46% (95% CI 0.5–0.5)) | 316,800 |
| 14 | Condition has a cut but not deep enough to reach the ply or cords | Tyres | 4.4% (95% CI 4.3–4.4) | 3.8 times (1.1% (95% CI 1.1–1.1)) | 301,660 |
| 15 | Swivel pins and bushes swivel pin and/or bush slightly worn | Suspension | 3.7% (95% CI 3.6–3.8) | 66 times (0.06% (95% CI 0.1–0.1)) | 86,437 |
| 16 | Integral vehicle structure condition is corroded but structural rigidity is not significantly reduced | Body, chassis, structure | 3.5% (95% CI 3.4–3.7) | 39 times (0.09% (95% CI 0.1–0.1)) | 74,771 |
| 17 | Tread depth worn close to legal limit/worn on edge | Tyres | 3.2% (95% CI 3.2–3.2) | twice (1.5% (95% CI 1.5–1.5)) | 3,822,709 |
| 18 | Wheel bearings has slight play | Suspension | 3.2% (95% CI 3.1–3.3) | 35 times (0.09% (95% CI 0.1–0.1)) | 95,742 |
| 19 | Chassis condition or chassis corroded within 30cm of a mounting, but not seriously affecting overall security | Body, chassis, structure | 3.0% (95% CI 2.8–3.2) | 41 times (0.07% (95% CI 0.1–0.1)) | 31,566 |
| 20 | Service brake performance fluctuating, but not excessively | Brakes | 2.8% (95% CI 2.7–2.9) | 14 times (0.20% (95% CI 0.2–0.2)) | 115,705 |
| 21 | Linkage pins and bushes pin or bush worn but not resulting in excessive movement | Suspension | 2.7% (95% CI 2.6–2.8) | 49 times (0.06% (95% CI 0.1–0.1)) | 80,908 |
| 22 | Exhaust system mounting defective | Body, chassis, structure | 2.6% (95% CI 2.5–2.6) | 18 times (0.14% (95% CI 0.1–0.1)) | 146,325 |
| 23 | Flexible brake hoses slightly deteriorated | Brakes | 2.5% (95% CI 2.4–2.7) | 92 times (<0.1% (95% CI 0.0–0.0)) | 57,008 |
| 24 | Headlamp has a product on the lens but not seriously reducing light output | Lamps, reflectors and electrical equipment | 2.4% (95% CI 2.3–2.5) | 35 times (0.07% (95% CI 0.1–0.1)) | 151,411 |
| 25 | Shock absorbers has a reduced damping effect | Suspension | 2.2% (95% CI 2.1–2.3) | 31 times (0.07% (95% CI 0.1–0.1)) | 45,193 |
| 26 | Suspension arm corroded but not seriously weakened | Suspension | 2.0% (95% CI 2.0–2.1) | 32 times (0.06% (95% CI 0.1–0.1)) | 209,642 |
| 27 | Service brake imbalance requirements only just met. It would appear that the braking system requires adjustment or repair. | Brakes | 1.9% (95% CI 1.8–2.0) | 16 times (0.11% (95% CI 0.1–0.1)) | 50,588 |
| 28 | Chassis condition is corroded but structural rigidity is not significantly reduced | Body, chassis, structure | 1.7% (95% CI 1.6–1.8) | 42 times (<0.1% (95% CI 0.0–0.0)) | 69,801 |
| 29 | Condition slightly damaged/cracking or perishing | Tyres | 1.7% (95% CI 1.7–1.7) | 4.6 times (0.37% (95% CI 0.4–0.4)) | 1,939,529 |
| 30 | Registration plates deteriorated but not likely to be misread | Identification of the vehicle | 1.7% (95% CI 1.6–1.7) | 34 times (<0.1% (95% CI 0.0–0.1)) | 466,754 |
| 31 | Flexible brake hoses has slight corrosion to ferrule | Brakes | 1.5% (95% CI 1.5–1.6) | 44 times (<0.1% (95% CI 0.0–0.0)) | 138,431 |
| 32 | Brake discs worn, but not excessively | Brakes | 1.5% (95% CI 1.5–1.5) | 3.5 times (0.43% (95% CI 0.4–0.4)) | 502,155 |
| 33 | Sub-frame corroded but not seriously weakened | Suspension | 1.5% (95% CI 1.4–1.5) | 21 times (0.07% (95% CI 0.1–0.1)) | 364,836 |
| 34 | Pins and bushes pin or bush slightly worn | Suspension | 1.5% (95% CI 1.3–1.6) | 80 times (<0.1% (95% CI 0.0–0.0)) | 23,076 |
| 35 | Sub-frame mounting prescribed areas prescribed area is corroded but not considered excessive | Suspension | 1.3% (95% CI 1.2–1.4) | 40 times (<0.1% (95% CI 0.0–0.0)) | 46,414 |
| 36 | Steering rack has slight free play detected at steering wheel | Steering | 1.2% (95% CI 1.0–1.3) | 61 times (<0.1% (95% CI 0.0–0.0)) | 27,995 |
| 37 | Macpherson strut corroded but not seriously weakened | Suspension | 1.2% (95% CI 1.0–1.3) | far higher (<0.1% (95% CI 0.0–0.0)) | 31,467 |
| 38 | Condition slightly damaged | Tyres | 1.0% (95% CI 1.0–1.1) | 2.9 times (0.35% (95% CI 0.3–0.4)) | 155,933 |
| 39 | Brake discs worn, pitted or scored, but not seriously weakened | Brakes | 0.77% (95% CI 0.8–0.8) | 6.0 times (0.13% (95% CI 0.1–0.1)) | 1,777,480 |
| 40 | Engine oil leaks leak, but not excessive | Noise, emissions and leaks | 0.68% (95% CI 0.7–0.7) | 12 times (0.06% (95% CI 0.1–0.1)) | 831,419 |
| 41 | Sub-frame condition is corroded but structural rigidity is not significantly reduced | Body, chassis, structure | 0.62% (95% CI 0.5–0.7) | 79 times (<0.1% (95% CI 0.0–0.0)) | 22,273 |
| 42 | Condition slightly distorted | Road Wheels | 0.52% (95% CI 0.5–0.6) | 30 times (<0.1% (95% CI 0.0–0.0)) | 163,219 |
| 43 | Pedal wearing smooth | Brakes | 0.41% (95% CI 0.3–0.5) | far higher (<0.1% (95% CI 0.0–0.0)) | 27,507 |
| 44 | 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 | 0.29% (95% CI 0.2–0.3) | 21 times (<0.1% (95% CI 0.0–0.0)) | 50,658 |
| 45 | Other suspension component corroded but not seriously weakened | Suspension | 0.22% (95% CI 0.2–0.3) | 38 times (<0.1% (95% CI 0.0–0.0)) | 55,330 |
| 46 | Shock absorbers has slight external damage to the casing | Suspension | 0.18% (95% CI 0.1–0.2) | 25 times (<0.1% (95% CI 0.0–0.0)) | 48,395 |
| 47 | Coil spring corroded | Suspension | 0.13% (95% CI 0.1–0.1) | 14 times (<0.1% (95% CI 0.0–0.0)) | 587,235 |
| 48 | Non-obligatory stop lamp not working | Lamps, reflectors and electrical equipment | 0.13% (95% CI 0.1–0.2) | 11 times (<0.1% (95% CI 0.0–0.0)) | 54,730 |
| 49 | Transmission oil leaks leak, but not excessive | Noise, emissions and leaks | 0.12% (95% CI 0.1–0.1) | 21 times (<0.1% (95% CI 0.0–0.0)) | 110,031 |
| 50 | Anti-roll bar corroded but not seriously weakened | Suspension | <0.1% (95% CI 0.0–0.0) | 12 times (<0.1% (95% CI 0.0–0.0)) | 29,333 |
| 51 | Non-component advisories Child Seat fitted not allowing full inspection of adult belt | Non-component advisories | 0% (95% CI 0.0–0.0) | 0% (95% CI 0.0–0.0) | 433,540 |
| 52 | Non-component advisories Nail in tyre | Non-component advisories | 0% (95% CI 0.0–0.0) | 0% (95% CI 0.0–0.0) | 360,247 |
| 53 | Non-component advisories Play in steering rack inner joint(s) | Non-component advisories | 0% (95% CI 0.0–0.0) | 0% (95% CI 0.0–0.0) | 241,394 |
| 54 | Non-component advisories Items removed from driver's view prior to test | Non-component advisories | 0% (95% CI 0.0–0.0) | 0% (95% CI 0.0–0.0) | 137,470 |
| 55 | Non-component advisories Vehicles internal headlight adjuster altered to recheck lights | Non-component advisories | 0% (95% CI 0.0–0.0) | 0% (95% CI 0.0–0.0) | 38,870 |
| 56 | Non-component advisories Coolant leak | Non-component advisories | 0% (95% CI 0.0–0.0) | 0% (95% CI 0.0–0.0) | 35,882 |
| 57 | Non-component advisories Fuel Pipe/s corroded | Non-component advisories | 0% (95% CI 0.0–0.0) | 0% (95% CI 0.0–0.0) | 33,464 |
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. The same vehicle_id failed on that same certificate line in 2025.
- Rank statistic. fail_same_rate = same-item 2025 failures ÷ 2024 advisory-and-pass cohort. Highest rate is rank 1.
- Inclusion. Cohort of at least 20,000 cars. Below that the rate is not ranked here (the item page may still exist if it meets the registry floor of 500).
- Ties. Larger cohort, then certificate wording A–Z.
- Shown, not used to rank. fail_same_control is the same-item fail rate among 2024 passes that did not carry the advisory. The lift is the ratio of the two rates when the control rate is above zero.
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 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 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.