What Are the Most Common Reasons That Cars Fail Their MOT?

These items come up again and again as MOT fails. The list is not a ranking and it is not a count of tests.

1. Faulty Brakes: Worn pads, damaged discs, low fluid, or imbalanced braking force all lead to an instant fail. Listen for squeals, grinding, or pulling under braking and have problems fixed promptly.

2. Worn Tyres: Tyres must have at least 1.6mm tread depth across the central three-quarters and show no cuts or bulges. Underinflated or mismatched tyres can also raise concerns.

3. Lights and Indicators: Broken bulbs, misaligned headlights, or cracked lenses remain one of the simplest reasons for failure. Check every light, including fog and reversing lamps, before the appointment.

4. Emissions and Exhaust Issues: Excessive smoke, a damaged catalytic converter, or exhaust leaks will not pass the test. Regular servicing keeps the system efficient and compliant with legal limits.

5. Suspension Problems: Worn shock absorbers, broken springs, or noisy suspension joints compromise handling and safety, so they are closely inspected.

6. Windscreen Damage: Cracks or chips in the driver's line of sight, or significant damage elsewhere, are classed as dangerous and will fail immediately.

The free MOT history check shows earlier fails and advisories for a registration, including mileage at each test. Counts of classified failure comments from vehicles checked through VehicleScore are in MOT failure reasons. This page does not book a test.