Every year, millions of vehicles across the UK undergo an MOT test. While many pass without issue, a large number fail due to problems that could have been spotted and fixed beforehand.
The good news is that many MOT failures are caused by simple issues that are easy and inexpensive to put right.
Here are some of the most common reasons cars fail an MOT in the UK.
1. Faulty Lights
One of the biggest causes of MOT failures is defective lighting.
This includes:
- Headlights not working
- Brake lights failing
- Indicators not flashing correctly
- Number plate lights not working
Many drivers don’t realise a bulb has failed until the MOT test. Checking all your lights before your test takes only a few minutes and could save you a fail.
2. Worn Tyres
Tyres must meet the legal minimum tread depth of 1.6mm across the central three-quarters of the tyre.
Your vehicle may fail if:
- Tread depth is below the legal limit
- Tyres are damaged
- There are cuts, bulges or exposed cords
Regular tyre checks can help avoid an unexpected failure.
3. Windscreen Damage
A chipped or cracked windscreen can result in an MOT failure depending on its size and location.
Damage is taken particularly seriously if it affects the driver’s view of the road.
Even a small chip can grow into a larger crack if left untreated.
4. Brake Problems
Brakes are one of the most important safety components on any vehicle.
Common brake-related failures include:
- Worn brake pads
- Damaged brake discs
- Poor braking performance
- Brake fluid leaks
If your brakes feel unusual or make grinding noises, it’s worth getting them checked before your MOT.
5. Suspension Issues
Suspension helps keep your car stable and comfortable on the road.
Your MOT may identify:
- Worn shock absorbers
- Broken springs
- Damaged suspension components
Common signs include knocking noises, uneven tyre wear and poor handling.
6. Poor Visibility
Drivers need a clear view of the road at all times.
Problems that can lead to an MOT failure include:
- Worn windscreen wipers
- Empty screen wash bottles
- Excessive windscreen damage
- Mirrors that are damaged or insecure
These are often quick and inexpensive fixes.
7. Emissions Problems
Modern MOT tests include emissions checks to ensure vehicles meet environmental standards.
Common causes of failure include:
- Engine management warning lights
- Faulty sensors
- Exhaust system issues
- Excessive smoke emissions
If your engine warning light is illuminated, it’s best to investigate the issue before booking your MOT.
8. Seatbelts
All seatbelts must function correctly and be in good condition.
Your car may fail if:
- Seatbelts do not latch securely
- The belt is damaged
- The mechanism does not retract properly
Because seatbelts are critical safety equipment, defects are treated seriously.
How to Improve Your Chances of Passing an MOT
Before your MOT, carry out a simple inspection:
- Check all lights
- Inspect tyre tread depth
- Test windscreen wipers and washers
- Ensure warning lights are not illuminated
- Check mirrors and seatbelts
- Top up fluids where necessary
A few minutes of preparation can prevent many common failures.
You should always consider fixing last years advisories before the next MOT!
https://www.gov.uk/check-mot-history
Final Thoughts…
Many MOT failures occur because of small issues that drivers overlook. Checking your vehicle before the test can improve your chances of passing first time and save both money and inconvenience.
If your engine warning light is illuminated, it’s best to investigate the issue before booking your MOT. Seatbelts All seatbelts must function correctly and be in good condition. Your car may fail if any seatbelt is frayed, damaged, or does not retract properly. Because seatbelts are critical safety equipment, defects are treated seriously. A malfunctioning seatbelt not only compromises passenger safety but may also lead to severe repercussions during the inspection process. How to Improve Your Chances of Passing an MOT Before your MOT, carry out a simple inspection: check fluid levels, brakes, lights, and tyres. A few minutes of preparation can prevent many common failures. Ensure that your headlights and taillights are functioning, and that your tyres meet the legal tread depth requirement. Additionally, examine your wiper blades and windscreen for any damage that could impair visibility. Final Thoughts… Many MOT failures occur because of small issues that drivers overlook. Checking your vehicle before the test can improve your chances of passing first time and save both money and inconvenience. Whether it’s a blown bulb, worn tyre, or cracked windscreen, dealing with problems early is always the best approach. Regular maintenance and attention to detail can significantly enhance your vehicle’s performance during the MOT.