Things That Will Fail An MOT

When your car goes in for its annual MOT test, there are a lot of thing that can go wrong.

Sure, it might pass with flying colours, but there are so many potential mechanical issues that can throw a spanner in the works. That’s why it’s important to know – and prepare against – everything can can cause an MOT failure.

What things cause an MOT Fail?

The following is the complete checklist of everything that will be tested and needs to be in good working order for your car to be safe.

Body, vehicle structure & general items
- They should be free from corrosion and other damage, with no sharp edges that could cause injury.
Towbars
- They will be inspected to determine secureness, condition & any repairs or modifications that have been made.
- The speedometer, 13 pin electrical socket & engine mountings will also be checked over.
Fuel system
- It will be inspected for leaks, loose fittings or degradation & whether the fuel cap seals properly.
Exhaust emissions
- A standard emissions test will be completed to see if your car is producing too much pollution.
Exhaust system
- It should be free from leaks and have all of the required parts, including a catalyst when there should be.
Seatbelts
- They should be in good condition, work properly and attached securely.
Seats
- They will be checked that they are firmly secured in the vehicle and can be fixed in position, with the driver’s seat being adjustable.
Doors
- The latch, hinges & catches should be secure when the door is closed, and the doors should be openable from the outside (and inside in the front).
Mirrors
- A minimum number of mirrors needs to be present, and they need to be in working condition.

Load security
- The boot or tailgate should be able to close securely.
Brakes
- Their condition will be inspected, the anti-lock braking & electronic stability control will be tested and the overall performance of the brakes will be assessed.
Tyres & wheels
- Their condition, fitting, tread size & tread depth will be examined.
Registration plates
- The condition, attachment, colour & character spacing will be checked to ensure everything is legal.
Lights
- The dipped & full-beam headlights should be in working order, aimed directly in front of the car and clean.
Bonnet
- It should close securely.
Wipers & washers
- They should work well enough to keep the driver’s vision clear.
Windscreen
- The condition of the windscreen should not impede the driver’s view of the road.
Horn
- It should be suitable for the vehicle and work properly.
Steering & suspension
- They should be in good working condition with appropriate levels of fluids, with no damage or ill-fitting to piping.
VIN (Vehicle Identification Number)
- A VIN should be displayed.
Electrical
- Electrical wiring & the vehicle’s battery will be checked.

What Are The Categories Of An MOT Fail?

Here is a breakdown of MOT issue classifications. Not all result in a fail, so it’s important to broadly understand which faults result in a MOT fail.

As of 2018, there are four categories of problems that your faulty car might fall into.

Your car will pass with…

Advisories

These have been around for a long time now. They indicate things that are not yet faulty, but will soon become faulty.

Minor defects

These are current problems with your vehicle, but they’re not serious enough for it to fail the MOT test.

Your car will fail with…

Major defects

These are problems that are serious and need to be repaired before the test can be passed. However, they will not prevent you from driving your car away if your existing MOT certificate is still valid.

Dangerous defects

These are the most serious problems of all, and will mean that your car cannot leave the test centre, except on the back of a tow truck – You cannot legally drive it until the faults are fixed.

What are the common failures?

The second important thing to know is what are the common failures. The ones which, despite them being cheap to fix and simple to spot, will still result in a fail.

Check that all of your lights are working – Failing because of a silly little lightbulb can be a pain. Sure, it’s easy & cheap to fix, but that failure is on the car’s record forever.
Make sure your tyres are legal – If even one of your tyres is below the legal limit of tread, or is damaged, your car will fail. Get the tyre(s) replaced ahead of the test for a first-time pass.
Fill your washer fluid – This is one of the simplest reasons for failing an MOT imaginable! If your car doesn’t have washer fluid in its reservoir, it won’t pass the test.
Remove custom decorations – People like to personalise their stuff, and that often extends to their cars. Anything on the outside that could be deemed a danger to other road users (like ornaments) or anything inside that restricts your road view will result in an MOT fail.

We strongly advice checking for these yourself and if you have time, completing a full MOT preparation check, before you send the car in.

Concerned about passing your MOT? Here’s some more helpful advice

MOT FAQs

Can your car fail an MOT test for being dirty?

Yes. Believe it or not, your car will fail its MOT if it’s filthy – inside or outside. It’s your responsibility to keep your vehicle clean enough for the test technicians to properly assess it.

If you’ve got mountains of fast food bags or plastic bottles in the passenger seat footwell, they could refuse to test it. Similarly, if the car’s exterior is caked in mud – especially on the windscreen – then they might not be able to complete certain tests.

Aside from MOT tests, you can also be fined for driving around in a car that’s excessively dirty or messy!

Do garages fail MOTs on purpose?

Absolutely not. There might be rumours around MOTs (and driving tests, too) that test centres have a quota to meet by failing enough people. However, with regards to MOT tests, this is totally untrue. No genuine, honest MOT technician is going to deliberately fail your car for no reason.

If you do believe your vehicle has been failed when it should have passed, you are able to appeal the test result.

Can police see if you a failed MOT test?

Yes. If your car has failed its test and you’re currently driving about without a valid MOT, an ANPR (Automatic Number Plate Recognition) camera will flag this to the authorities. With ANPR cameras now so commonplace, it’s unlikely you’ll get away with this for long!

Sell your MOT failed car

If you want to get rid of a car which has failed it’s MOT test, or is damaged beyond repair, you can get an instant and free quote online. Simply add your reg number and postcode and we can find you a salvage buyer in your area.

Find out more

MOT Failure Hub

If you have, or expect to, fail you next MOT test there are a number of options, and important things to know. Luckily, we have expert guides on all MOT failure topics.

Things That Will Fail An MOT

What things cause an MOT Fail?