27% of car MOTs in 2025 found at least one defect that failed the test: 8,578,996 of 31,475,521. The most common reasons were tyre damage (1 in 26 MOTs), headlight aim (1 in 33) and sidelights and rear lights (1 in 41).
Share of all car MOTs in 2025 that failed on each part. One MOT can fail on more than one, so these add up to more than the 27% that failed.
What the MOT inspection manual says about each, and how often it failed in 2025.
| Question | Failed MOTs | Share of MOTs |
|---|---|---|
| What makes suspension fail the MOT? | 2,756,281 | 8.76% |
| What makes a tyre fail the MOT? | 1,984,532 | 6.30% |
| Is headlight alignment an MOT failure? | 1,536,466 | 4.88% |
| Is a broken brake light an MOT failure? | 619,666 | 1.97% |
| What makes a number plate fail the MOT? | 484,168 | 1.54% |
| What makes a handbrake fail the MOT? | 469,795 | 1.49% |
| Is the engine management light an MOT failure? | 466,296 | 1.48% |
| Is rust an MOT failure? | 440,807 | 1.40% |
| Is a split CV boot an MOT failure? | 423,383 | 1.35% |
| What makes a car fail the MOT on emissions? | 375,008 | 1.19% |
| Are worn brake discs an MOT failure? | 246,780 | 0.78% |
| Is a broken fog light an MOT failure? | 158,829 | 0.50% |
| Is a worn wheel bearing an MOT failure? | 126,594 | 0.40% |
| Is an airbag warning light an MOT failure? | 125,938 | 0.40% |
| Is the ABS warning light an MOT failure? | 120,883 | 0.38% |
| Is an oil leak an MOT failure? | 38,328 | 0.12% |
| Is a cracked windscreen an MOT failure? | 24,150 | 0.08% |
| Are faulty daytime running lights an MOT failure? | 10,828 | 0.03% |
| Is a DPF warning light an MOT failure? | 1,468 | 0.00% |
Going by 2025 MOT results, tyre damage: 3.8% of car MOTs failed on it. Next were headlight aim (3.0%) and sidelights and rear lights (2.5%).
27.3% of car MOTs in 2025 found at least one defect that failed the test, counting cars that were fixed within the hour. That's 8,578,996 of 31,475,521 first MOTs on cars first used 2005 to 2022.