With numerous vital components in near-constant use, it’s no wonder that vehicles often fail their MOTs.

The complex parts which make up your vehicle can experience gradual deterioration as they age, which is why regular servicing is so important in advance of an MOT test.

Read on and find out everything you need to know about MOT failure.


How Can I Avoid MOT Failure?

Regular car servicing throughout the year is a must if you ever hope to avoid MOT failure.

As your test approaches, make sure you book a pre-MOT check on your vehicle in plenty of time – this can help you spot and fix any issues which could lead to a fail.

You can also carry out a pre-MOT check at home by following our MOT checklist



What Happens If My Car Fails Its MOT?

You will always learn your MOT result as soon as the mechanic finishes the test.

If your vehicle passes, the garage will fill out the VT20 pass form, sort out payment and send you on your way.

If your vehicle fails, you will be issued with a ‘refusal’ of an MOT certificate VT30 form. Your mechanic can then talk you through why your car failed its test.


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What Are MOT Defect Categories?

There are four main types of faults: minor, major, dangerous and advisory.

Major and dangerous faults will lead to immediate MOT failure, whilst advisories and minor faults won’t lead to a fail.

Even so, these issues should be repaired as soon as possible.



A minor defect is one which isn’t serious enough for the vehicle to fail the test.

A minor defect can be found on a component which has suffered slight damage, but is still working well.

Minor defects are not that common – any worn or damaged components are more likely to be classed as major defects, or as an advisory item.

Examples of minor defects include a rear registration plate lamp which isn’t working properly, or something which is obstructing the driver’s field of view.

You can easily avoid a minor defect by performing a pre-MOT check on your vehicle ahead of the test, which can save you time and money in the long run.



Defects which are failure items but are not seen as dangerous are known as major defects.

Major MOT defects will cause an instant MOT fail, and you will not pass the test until these defects have been rectified.

Major defects include a shock absorber or exhaust system with a substantial fluid leak.

Major faults pose an immediate safety risk, so it is important that you have these fixed right away.



The most serious of the failure notices, a dangerous defect will lead to an instant fail.

As such, a dangerous defect will invalidate any remaining days on your current MOT, meaning it is now illegal to drive your vehicle on a public road.

You must have any dangerous defects fixed right away. Such defects include significantly worn brake lining or pads or a fractured road wheel.

Your vehicle will not be roadworthy or safe to drive until you have these issues fixed.



In addition to the MOT defect categories listed above, MOT testers can declare faults as advisories if they believe that a fault may soon become apparent.

Whilst an MOT tester does not have to tell you about any advisories, a good MOT tester will.

Your vehicle will not fail its MOT due to an advisory notice, but it can fail a future MOT test if you do not rectify these faults soon.

A worn shock absorber bushing or a worn tyre with around 1.6mm tread depth – the minimum limit – are examples of advisories.


Mechanic holding a clipboard completing an MOT inspection

A mechanic can find any of these four faults during an MOT - and major and dangerous faults can lead to instant MOT failure.


What Should I Do About MOT Failure?

If your car fails its MOT, you can leave it at the test centre for essential repairs to be carried out.

Provided these repairs are done within 10 working days of the test, the car can be retested free of charge.

In the event you want your vehicle to be repaired somewhere else, then you can still have it retested for free at the original test centre so long as you return it before the end of the next working day.

Please know that you may only take the car elsewhere if its current MOT certificate is valid, and the MOT test did not highlight a dangerous defect.


What Is a Retest?

An MOT retest is a partial test which is carried out after the initial MOT test - a retest will generally only check the parts of your car which failed the initial test.

If you don’t have the issues affecting your vehicle fixed and then book a retest, then you won’t be able to drive the vehicle.

If your current MOT certificate has not yet expired, then you will only be allowed to drive the vehicle to a garage for repairs or for the retest – it is illegal to drive it anywhere else.

When you choose a garage through BookMyGarage, please know that every garage on our site offers a free MOT retest and affordable MOT repairs.

During an MOT retest, the mechanic will check that the repairs have fixed the original cause of the failure. This is free for a wide variety of defects, including those affecting the wheels, tyres, mirrors, doors, lamps and indicators.

You don’t need to book an MOT retest separately. Once the garage has completed the necessary work, they will complete the retest and issue you with an MOT pass certificate.


Can I Appeal Against a Failed MOT Test?

If your vehicle has failed its MOT, then you need to discuss your results with the test centre before any repairs can be carried out.

You can appeal the result of the MOT if you think it is wrong by filling in the complaint form and sending it to the DVSA within 14 working days of the test.

The DVSA will contact you within 5 days to discuss the appeal.

In the event the DVSA are happy to recheck your vehicle, you will need to arrange a date and pay the full test fee again.

If your appeal is successful, then you will be refunded the test fee.

You should only begin this process if you are convinced that your car should have passed its original test – if the independent tester feels the failure was justified, you’ll have to pay for repairs, the original test and potentially two retest fees.


Mechanic in dungarees inspecting car during an MOT retest

Any MOT appeal will be completed by an independent tester. Your car must pass for you to get any sort of refund.


Can I Still Drive After a Failed MOT?

It is illegal to drive without a valid MOT, and you could face a £1000 fine for doing so.

You may only drive your vehicle if you are heading to a garage or a pre-booked MOT test or repair which is designed to fix defects highlighted during a previous MOT test.

Your vehicle must be insured to do this – you could invalidate your car insurance and face a £300 fine and 6 points on your licence if you drive without an MOT.

If your vehicle has a dangerous defect at the MOT, the vehicle cannot be legally driven on the road until the necessary repairs have been carried out and the vehicle passes a retest. 

If your vehicle had a major defect at the MOT, any remaining MOT from a previous test will still be valid because you booked your test early. 

Whilst you can technically still drive if your previous MOT certificate is still valid, we would strongly advise against this. A major fault means that there is a safety-related issue with your vehicle which needs to be fixed as soon as possible. 

If you need to move your vehicle under any other conditions, then you will need to book a tow truck.

The same is true if your classic car fails an MOT – even though it doesn’t legally require one.


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If you would like to check when your MOT is due, you can use our free MOT checker.

We hope that you have enjoyed learning about MOT failure. If your vehicle has failed its MOT, we have plenty of resources to help you when it comes to understanding MOT testing.