Yes, if a brake light is missing or doesn't work, doesn't show a steady red light, is much dimmer than it should be, or comes on late. A brake light that stays on after you let go of the brake is a dangerous defect.
Testers grade each defect: a major or dangerous defect fails the MOT, a minor one passes but is written on the certificate.
| Defect | Result |
|---|---|
| Stop lamp(s) with a multiple light source up to 1/2 not functioning | PassesMinor |
| Stop lamp(s) missing, inoperative or in the case of a multiple light source more than 1/2 not functioning | FailsMajor |
| Stop lamp(s) all missing or inoperative | FailsDangerous |
| A lens defective which has no effect on emitted light | PassesMinor |
| A lens defective such that the emitted light is adversely affected | FailsMajor |
| A stop lamp not securely attached | PassesMinor |
| A stop lamp likely to become detached | FailsMajor |
| Defect | Result |
|---|---|
| Stop lamp(s) switch does not operate in accordance with the requirements | PassesMinor |
| Stop lamp(s) switch with a delay in operation | FailsMajor |
| Stop lamp(s) remain on when the brakes are released | FailsDangerous |
| Defect | Result |
|---|---|
| A stop lamp position or intensity not in accordance with the requirements | PassesMinor |
| A stop lamp not showing a steady red light or has significantly reduced light intensity | FailsMajor |
| A stop lamp adversely affected by the operation of any other lamp | FailsMajor |
From DVSA's MOT inspection manual for cars and passenger vehicles. Contains public sector information licensed under the Open Government Licence v3.0.
In 2025, 619,666 car MOTs failed on brake lights: 1.97%, or about 1 in 51. 5% of those failures were for a dangerous defect. Another 65,038 MOTs recorded it as a minor defect, which passes. Testers also noted it as an advisory on 101,192 MOTs: something to keep an eye on that didn't fail the test.
Share of the MOTs that failed on brake lights. One MOT can fail for more than one reason.
Share of car MOTs in each mileage band that failed on brake lights.
4.38% of MOTs on cars registered in 2005 failed on brake lights, against 0.19% for cars registered in 2022.
Models that failed on brake lights at least 1.15 times as often as the average car of the same age and mileage, out of 90 with at least 30 MOTs failed on it.
Least often: Jaguar XF (0.1×), Land Rover Discovery Sport (0.1×), Mercedes E-Class (0.1×), Audi Q5 (0.1×), Kia Niro (0.1×).
Yes, if one doesn't work
In 2025, 619,666 car MOTs failed on brake lights, about 1 in 51. 5% of those were rated dangerous.
1 in 51car MOTs failed on brake lights in 2025
65,038minor defects recorded in 2025, which pass
Yes, if a brake light is missing or doesn't work, doesn't show a steady red light, is much dimmer than it should be, or comes on late. A brake light that stays on after you let go of the brake is a dangerous defect.
In 2025, 619,666 car MOTs failed on brake lights: 1.97%, or about 1 in 51. 5% of those failures were for a dangerous defect.
Against the average car of the same age and mileage, the Ford EcoSport (7.5 times as often), Ford Fiesta (2.9 times as often) and Suzuki Vitara (2.8 times as often), going by 2025 MOT results.