What Fails Most on MOTs? The Complete Breakdown

Every year, millions of UK drivers are caught out by MOT failures that could have been spotted – and fixed – weeks earlier at home or on a quick visit to a local garage.

In our previous studies we looked at the cars most likely to fail their next MOT and the most reliable used cars at MOT (age 6–9 years). This time we’re not focusing on specific models at all. Instead, we’re asking a simpler question:

What actually fails most on UK MOT tests – and which of those problems can you prevent before test day?

At Pre MOT Check, we’ve built our platform on top of the DVSA’s anonymised MOT data. For this analysis, we dug into 2023 MOT test results to see which parts of the car fail most often, and which exact defects come up again and again on MOT failure sheets.

The answer is surprisingly clear: a handful of categories – tyres, suspension and brakes – account for the majority of failures, and many of those are avoidable with basic maintenance.

The big picture: which MOT failure categories dominate?

First, let’s look at MOT failures by broad category for 2023.

Category	Total Failures	% of All Failures
Tyres	5,951,404	38.5%
Suspension	4,987,956	32.3%
Brakes	3,131,699	20.3%
Lighting	377,209	2.4%
Steering	210,733	1.4%
Corrosion / Structure	134,066	0.9%
Wipers / Windscreen	129,495	0.8%
Exhaust	109,770	0.7%
Other	371,291	2.4%

Three things stand out straight away:

Tyres and suspension together cause over 70% of all MOT failures.
Brakes account for roughly 1 in 5 failures.
Everything else – lights, visibility, exhaust, structure – is relatively small by comparison.

So if you want to dramatically reduce your risk of failing an MOT, tyres, suspension and brakes are where you should focus first. For a detailed guide on what to check before your test, see our complete MOT checklist.

The top 10 specific MOT failure reasons

Broad categories are useful, but when you look at the most common specific failure reasons, the picture gets even clearer.

Rank	Failure Reason	Failure Count (2023)
1	Tyre tread depth below requirements	3,994,297
2	Suspension pin, bush or joint worn	2,865,497
3	Tyre seriously damaged	1,884,970
4	Spring fractured or weakened	1,175,530
5	Brake pipe damaged or corroded	1,129,963
6	Brake lining / pad worn below 1.5mm	959,629
7	Brake disc / drum weakened or fractured	857,874
8	Structural corrosion near mounting points	315,223
9	Shock absorber not functioning / leaking	233,831
10	Suspension component corroded	214,979

Again, tyres, suspension and brakes completely dominate. Four of the top ten are tyre‑related, four are suspension‑related and three are brake‑related (with some overlap).

The good news is that many of these issues give warning signs long before the MOT tester writes them down.

The “big three”: tyres, suspension and brakes

1. Tyres – the number one MOT killer

With nearly 4 million failures for tread depth alone, tyres are easily the most common MOT problem.

Common issues:

Tread depth below the legal minimum of 1.6mm across the central three‑quarters of the tyre.
Sidewall damage from kerbs or potholes.
Bulges, cuts or exposed cords.
Uneven wear from poor alignment or worn suspension.

What you can do:

Check your tyres monthly using a 20p coin or tread gauge.
Look along the sidewalls for cuts, bulges and cracks.
Rotate tyres and get wheel alignment checked if you notice uneven wear.

If your car regularly appears on the "worst tyres" lists in our database, the detailed MOT stats page for your car will flag this clearly and include tyre‑specific checks in your pre‑MOT checklist. For example, see tyre-related failures on the 2015 Ford Fiesta MOT pass rate page or the 2015 Vauxhall Corsa common MOT failures.

2. Suspension – worn joints and broken springs

Suspension issues account for nearly a third of all failures, and they're particularly common on heavier vehicles (like vans) and cars used on poor‑quality roads. For a detailed breakdown by manufacturer, see our suspension failure analysis by brand.

Common issues:

Worn suspension pins, bushes and ball joints.
Broken or weakened springs.
Leaking or ineffective shock absorbers.
Corroded suspension components.

Warning signs you might notice:

Clunks, knocks or rattles over bumps.
The car feeling “floaty” or unstable at speed.
Uneven tyre wear or the car sitting low on one corner.

If you drive a model that already has a high MOT failure rate for suspension – something you can see on its Pre MOT Check stats page – it's worth asking a garage to inspect these components before test day. Models like the 2017 VW Golf and 2016 Nissan Qashqai show their specific suspension failure patterns on their stats pages.

3. Brakes – wear, corrosion and neglect

Brakes account for just over 20% of MOT failures. Some of these are serious safety concerns that develop quickly, but many are predictable wear items that have simply been left too long.

Common issues:

Pads worn below the minimum thickness.
Discs corroded, scored or cracked.
Brake pipes corroded or damaged.
Parking brake (handbrake) efficiency too low.

Warning signs:

Squealing, grinding or scraping noises when braking.
The car pulling to one side under braking.
A soft or spongy brake pedal.
Handbrake needing to be pulled up higher than usual.

If you notice any of these symptoms, don't wait for your MOT. Get them checked – you'll improve safety and reduce the chances of more expensive repairs later. Check brake failure rates for popular models like the 2012 BMW 3 Series MOT statistics or 2015 Audi A3 MOT pass rate.

Easy fixes vs expensive surprises

Not all MOT failures are created equal. Some can be fixed quickly and cheaply; others point to deeper problems or bigger bills.

Common “easy fix” failures:

Low tyre tread (if spotted early enough to shop around for replacements).
Blown bulbs or poorly aimed headlights.
Worn wiper blades and smeared windscreens.
Washer jets not working due to blocked nozzles or low fluid.

These are exactly the kinds of issues you can catch by following a pre‑MOT checklist at home.

Likely “expensive surprise” failures:

Multiple suspension joints or springs needing replacement at once.
Extensive brake corrosion requiring discs, pads and possibly pipes.
Structural corrosion near suspension or subframe mounting points.
Serious exhaust or emissions issues on older vehicles.

For these, prevention is mainly about regular servicing and not ignoring early warning signs (noises, vibrations, dashboard lights) in the months leading up to the MOT.

On Pre MOT Check, each model/year MOT stats page highlights the most common failure categories for your specific vehicle – so you know whether tyres, suspension, brakes or corrosion are the bigger risk for your next test.

Turn the data into a pre‑MOT checklist

You don’t need to become a mechanic to benefit from this data. A simple, structured walk‑around can eliminate many of the top failure reasons before they reach the test station.

We’ve marked each section below as either “(check at home)” or “(ask a garage)” so you know what you can realistically tackle yourself.

Here’s a high‑level checklist based on the national failure patterns above:

Tyres (check at home)
- Check tread depth across the whole width of all four tyres and the spare (if fitted).
- Inspect sidewalls for bulges, cuts, cracking or exposed cords.
- Make sure tyre sizes and load ratings match across each axle.
Brakes (check at home, fix at a garage)
- Listen for squealing or grinding noises.
- Check for pulsation or pulling to one side when braking.
- Test the handbrake on a gentle slope – it should hold the car firm.
Suspension & steering (ask a garage)
- Drive slowly over speed bumps and listen for clunks or rattles.
- Check that the car sits level and doesn’t bounce excessively when pushed down at each corner.
- Notice any vagueness or wandering in the steering, especially at motorway speeds.
Lights & visibility (check at home)
- Turn on all lights (including fog and number plate lights) and walk around the car.
- Check indicators, hazards, brake lights and reverse lights.
- Inspect wiper blades and top up screenwash; make sure jets spray correctly.
Windscreen & mirrors (check at home)
- Look for chips or cracks in the driver’s line of sight.
- Ensure mirrors are secure and adjust correctly.
Exhaust & emissions (check at home, ask a garage if you spot issues)
- Listen for unusual exhaust noises or blowing sounds.
- Watch for excessive smoke on startup or under acceleration.

For an even more tailored list, you can look up your car by make, model and year on our MOT pass rate by make and model page. Each vehicle page turns its most common MOT failures into a dedicated pre‑MOT checklist. For example, see the 2013 Ford Focus MOT checklist or 2013 Vauxhall Astra pre-MOT checks.

Check your car’s MOT stats by number plate

Methodology & data sources

This study is based on the same underlying dataset we use across Pre MOT Check:

Data source: DVSA MOT test results, 2023 (anonymised car and light van tests).
Tests analysed: 40.7 million MOT tests across the UK.
Grouping: Failures aggregated by high‑level category (tyres, suspension, brakes, etc.) and by specific defect codes.
Metrics: Counts and percentages of failures per category and per top defect reason.
Scope: Passenger cars and light commercial vehicles; motorcycles and heavy goods vehicles are excluded.

We refresh our data when new DVSA datasets are released. The category‑level patterns tend to be very stable year‑on‑year, but individual models move up and down the rankings – something you can see on each detailed MOT stats page for your car.

If you’re interested in how this compares with the worst and best‑performing models, check out:

Frequently Asked Questions

What are the most common MOT failures?

The three most common MOT failure categories are tyres (38.5% of all failures), suspension (32.3%), and brakes (20.3%). Together, these account for over 90% of all MOT test failures. The single most common specific defect is tyre tread depth below the legal 1.6mm minimum.

What is the minimum tread depth for MOT?

The legal minimum tread depth for MOT is 1.6mm across the central three-quarters of the tyre. However, it's recommended to replace tyres when tread reaches 3mm for optimal safety. Tread depth failures account for nearly 4 million MOT failures per year.

What is the most expensive MOT failure to fix?

The most expensive MOT failures are typically structural corrosion near suspension mounting points (often £500+), multiple suspension component replacements, and extensive brake system corrosion requiring discs, pads and pipes. These are harder to prevent and often indicate longer-term neglect.

How can I reduce my MOT failure risk?

Focus on the 'big three': check tyres monthly (tread depth, condition, sidewalls), listen for brake squealing or grinding noises, and address any clunks or knocks from suspension promptly. Use a pre-MOT checklist 2-4 weeks before your test to catch issues early.

Key takeaways

Tyres, suspension and brakes account for the vast majority of MOT failures, with tyres alone responsible for nearly 4 million fails in 2023.
Many of the most common defects – especially tyre tread, basic brake wear and simple visibility issues – can be spotted and fixed before the MOT with a basic checklist.
Structural corrosion, major suspension work and serious brake problems are rarer but more expensive; catching them early makes a big difference to cost and safety.
Using model‑specific data from Pre MOT Check helps you prioritise the items most likely to fail on your car, not just the national averages.

To see how your car compares, browse all makes and models or search your registration on the Pre MOT Check home page. You’ll get instant MOT statistics and a checklist tailored to your vehicle.