There is many reasons why your car may fail its MOT. Some of them you can do something about before the test and others are unavoidable. The comprehensive MOT failure list goes over all the ways a car can fail an MOT and some useful MOT prechecks that can help you pass.

What is an MOT?

An MOT is an annual assessment of the road worthiness and emissions of your vehicle. You are required to have a valid MOT certificate to drive on public roads in the UK. It is a check of the safety of your vehicle, not the health of your vehicle, regular servicing is still important.

When is my MOT Due?

You can find the expiry date of current MOT on your test certificate, or the easier way is to use our free MOT history check which can tell you as well.

Minor, Major and Dangerous defects

In 2018 the government changed how the grading system on an MOT works. When you take your car for an MOT, the mechanic will go through a checklist to inspect your car and will grade the defects into one of the following three categories:

  • Minor – This indicates that there is an issue with the vehicle, however currently the defect is not currently impacting the safety of the vehicle. These are highlighted so you can take proactive action and avoid a bigger problem on the next MOT. If the inspector believes that a small defect will develop into a bigger one then they will fail your MOT.
  • Major – A major fault will cause your vehicle to fail its MOT. This defect indicates that there is an issue that will impede the safety of your vehicle. It is still legal to drive after the failed MOT as long as the current certificate has not expired, however this is not recommended.
  • Dangerous -A dangerous fault will also cause you to fail your MOT, however the issue highlighted is more severe and the inspector believes it will be a danger on the road. Driving a car with a dangerous defect is an offense in all circumstances, the garage can not prevent you from leaving but the police can stop you if they scan your number plate.

When it comes to the MOT what is tested?

During an MOT your vehicle will be inspected to determine if it is road worthy. All inspectors will use the same MOT check list. These are the parts that will be inspected.

mot failure list - illustration showing which parts of the car is inspected during MOT.

Body, vehicle structure and other general items

  • Specific areas are checked for corrosion damage and signs of structural weakness.
  • The body is checked for any protruding sharp edges that could potentially cause harm.

Towbars (if applicable)

  • Will check for damage
  • Repairs or modifications that could impede the safety.
  • How securely it fits to the vehicle.
  • The 13 pin electrical socket is working safely and correctly.
  • Engine mountings are securely attached.

Fuel System

  • That no leaks are coming from the fuel system.
  • All pipes and hoses are not damaged and working as intended.
  • The fuel cap is able to fasten and seal correctly.

Exhaust Emissions

This one depends on the fuel type your vehicle uses and its age. The check is done to determine your vehicle meets the rules for exhaust emissions.

Diesel Cars

If you have a Diesel car there is a chance the MOT inspector will refuse to carry out the MOT as the smoke test has a chance to damage your engine. If you think this may apply to you then you need to make them aware at the start.

You can reduce the chance of your car being damaged and the odds of it passing the MOT with the following:

  • Service your vehicle regularly.
  • Get the camshaft drive belt replaced at the times recommended.
  • Warm up your engine before you go to the garage for the test, it will produce less smoke.
  • Do not interfere or tamper with the governor settings.

Exhaust System

  • A check to see if the exhaust is securely attached to the vehicle and no parts are missing.
  • Your catalyst is present and not removed.
  • There is no leaks and the noise is at an acceptable level.


  • That they are attached securely.
  • There is no fraying or damage to the belts.
  • The car has seatbelts for all seats in the vehicle.
  • They will provide a suitable amount of protection.
  • Can lock in securely.

In addition to this the dashboard warning lights will be checked for:

  • Seatbelt load limiters
  • Seatbelt pretensioners 
  • air bags


  • Can be adjusted and securely lock back into place.
  • Are securely fitted with the backs in an upright position.


  • All the internal mechanisms are in good condition.
  • The rear doors can be opened from the outside of the car.
  • The front doors can be opened from within both the inside and outside of the car.
  • The latch is secure when the door is closed.


  • The vehicle needs a minimum of two mirrors in different locations.
  • The mirrors provide an sufficient view and are secure.

Load Security

  • The boot or tailgate needs to be able to close securely.


The brakes are inspected for:

  • the condition, including any inappropriate repairs or modifications.
  • The efficiency test, which inspects their operation and performance.
  • The ABS (anti-lock braking system) and if you have one the ESC (electronic stability control).

The dashboard warning lights will be checked for:

  • ABS and ESC.
  • Electronic Park Brake.
  • Brake fluid warning lights.

Tyres and wheels

These are going to be checked for:

  • Tyre size and depth
  • The depth of the tread
  • Security
  • Are in good condition

If your vehicle was first used on or after 1 January 2012 it will also be checked to ensure that the tyre pressure monitoring system is working correctly.

Registration Plates

  • The registration plate needs to be securely connected to the car.
  • It has the required font and is spaced according to DVLA standards.
  • The colour matches the DVLA guidelines.
  • Is in good condition.


  • Are in good condition
  • operation, which includes the HID and LED lights.
  • The headlamps are checked for cleaning, security and self leveling.
  • The alignment of the headlamp is correct.
  • The main beam warning light on your dashboard is working.


  • The bonnet needs to be able to close securely.

Wipers and Washers

  • Wipers and washers are functioning and correctly clean the windscreen, ensuring that the driver has a clear view of the road.


  • That there is no cracks or damage to the windscreen.
  • That the windscreen provides a sufficient view of the road.


  • That it is in working condition.
  • It is suitable for the vehicle.

Steering and Suspension

  • Needs to be in good condition.
  • The steering lock mechanism needs to work correctly.
  • The steering oil level is checked to ensure there is sufficient power steering fluid.
  • That everything performs to an acceptable standard.
  • That no inappropriate repairs or modifications have taken place.

Vehicle Identification Number (VIN)

  • The VIN only appears on vehicles first used on or after 1 August 1980. The vehicle will be checked to ensure that a single VIN number is displayed.


  • Any visible electrical wiring will be checked along with the battery.

Most common failures

The top 10 most common reasons for failing your MOT are:

  1. Tyres – 1,101,839 Failures
  2. Coil springs – 1,069,069 Failures
  3. Headlamp aim – 806,993 Failures
  4. Wipers – 778,244 Failures
  5. Position lamps – 759,032 Failures
  6. Brake pads – 674,986 Failures
  7. Pins and bushes – 632,061 Failures
  8. Ball joints – 620,900
  9. Service brake performance – 615,329 Failures
  10. Rigid brake pipes – 522, 429
mot failure list - man preparing car for MOT

What to check before your MOT

As you can see the MOT test is quite extensive, it is one of the most thorough road safety tests in the world. You can’t prepare for everything but there is some things that you can do that will help avoid any unnecessary failures:

  • Do the 20p test on your wheel tyre treads to check the depth, if the outer ridge is not visible then it should be fine.
  • Make sure the number plates are clean, they need to be readable.
  • Check the fluid levels and top them up if necessary. This would include your screen wash, oil and brake fluid.
  • Check your mirrors are working and are secured properly.
  • Check all the lights are working.
  • Clean up your car, the tester can refuse to carry out the MOT if the car is unclean.
  • Give the horn a toot and check it is working.

If you do all of that then you give yourself a much better chance of a passing your MOT first time.

Once again, the MOT test is not to determine the health of your vehicle but just the safety. If you need to check when your MOT is due you can do so here just enter your number plate and you will get a free MOT History check.

If you need to book an MOT you can do so here.

Find out more about MOT’s

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