1 in 4 cars fail their MOT. Here is what actually goes wrong.

Roughly 10 million MOT tests a year end in a failure slip. The car that was fine on the school run this morning now needs work before it can legally be on the road.

The DVSA publishes the data behind those slips. We went through it to find out what actually goes wrong, which cars are worst, and what the repair bill looks like now. Every figure below is sourced from DVSA data, government publications, or named industry research.

The headline number: 28% fail first time

DVSA recorded an initial failure rate of 28.1% for class 3 and 4 vehicles (cars and light vans) in the 2024-25 testing year. After retests the final failure rate drops to about 21%.

That means roughly one in four cars is driven to a test centre in apparently working order and does not pass. The number has been broadly stable for years, but the cost of fixing it has not.

Age is the biggest predictor

A three-year-old car sitting its first MOT fails at about 13%. By ten years old, that rises to roughly 30%. By fifteen, it is above 40%.

This is not surprising, but the jump is steeper than most people expect. A garage doing its first MOT on a 2023 plate expects to pass almost nine out of ten. A garage testing a 2011 Corsa expects to fail almost half. The parts budget and the conversation with the customer are completely different jobs.

Age bracket	Approximate failure rate
3-4 years	~13%
5-7 years	~20-25%
8-10 years	~28-32%
11-14 years	~35-40%
15+ years	~42%+

Drawn from DVSA published data and DfT consultation documents. Exact rates vary by year and vehicle class.

What actually fails: lighting is a quarter of all defects

The single biggest category is lighting and electrical, which accounts for roughly 25.8% of all MOT defect items recorded, or over 7 million individual fault items in a year.

Think about that for a second. A blown headlight bulb, a dim number plate light or a dodgy indicator is responsible for more MOT failures than brakes and tyres combined.

Here is how the top categories break down:

Defect category	Share of all defect items
Lighting and electrical	~26%
Suspension	~15%
Brakes	~13%
Tyres	~10%
Body and structure	~8%
Steering	~5%
Emissions	~5%
Visibility (wipers, washers, mirrors)	~4%
Other	~14%

Percentages are approximate, drawn from DVSA-sourced breakdowns published by motdata.uk and cross-referenced with DVSA annual reporting.

Here is the bit that should annoy you: over 2.5 million MOT failures a year are linked to checks you can do yourself in ten minutes. The RAC Foundation puts that figure on simple items like replacing bulbs, checking tyre tread and topping up washer fluid.

A pre-MOT checklist stuck to the fridge would save millions of pounds a year in retest fees alone.

The cars that fail most (and least)

An analysis of 33.2 million first-attempt tests in 2025 by CarcostCheck ranked every make by failure rate:

Highest failure rates (by make):

Make	First-attempt failure rate
Tesla	15.9%
Land Rover	14.2%
Renault	13.8%
Citroen	13.5%
Vauxhall	12.9%

Lowest failure rates (by make):

Make	First-attempt failure rate
Lexus	4.8%
Honda	6.0%
Porsche	7.3%
Suzuki	7.5%
Toyota	7.6%

Tesla at the top is the headline, but the reason is mundane: EVs are heavier, and the extra weight wears suspension components and tyres faster. The Tesla Model Y had a 14.8% first-MOT failure rate across 19,000+ tests, with suspension and tyre-related defects leading. The Mercedes-Benz EQC was worse at 17.2%.

At the other end, Lexus and Toyota's reliability is so consistent that it barely needs saying. A Lexus at 4.8% fails at roughly a third of the rate of a Tesla.

At model level, the Citroen Berlingo recorded a 44.9% initial failure rate and the Citroen DS3 hit 44.7% in one analysis of 29.6 million tests, though these are older models sitting their fifth or sixth test, not first MOTs.

Where you live matters

MOT failure rates vary by region. The data is messier here because different studies measure different things, but the pattern holds:

• Greater Manchester had the highest failure rate in a 2025 HiQ sample at 54%, with Merseyside and Lancashire close behind
• London consistently records the highest pass rate, at 78-87% depending on the source and period
• The South East and South West tend to sit at the lower end, around 67% pass rate

The likely explanations: road surface quality (potholes wreck suspension and alignment), average vehicle age (London runs newer cars), and road salt in the north accelerating corrosion through winter.

The bill is going up

BookMyGarage tracked MOT-related invoices across its partner garages from 2022 to 2025. The trend is sharp:

• Cars aged 3-5 years: average repair bill of £332 (including the £54.85 test fee)
• Cars aged 6-8 years: average repair bill of £425
• One national garage group saw its average MOT booking invoice rise from £134 in 2022 to £227 in 2025, a 70% increase in three years
• A smaller regional network saw a 50% increase over two years, from £122 to £183

Parts prices, the growing complexity of modern cars, and ADAS calibration (a windscreen swap on a new Golf now means recalibrating the forward camera) all push the number up.

What this means if you own a car

Before your MOT:

1. Walk around the car. Check every light: headlights, brake lights, indicators, fog lights, number plate light, reverse light. Replace any blown bulbs. This one check eliminates a quarter of all failures.
2. Check your tyre tread. The legal minimum is 1.6mm across the central three-quarters of the tyre. A 20p coin is the classic test: if you can see the outer band of the coin, the tread is too low.
3. Top up your washer fluid. An empty washer bottle is an instant fail.
4. Check your wipers leave a clean sweep. Torn or perished blades are cheap to replace and common failures.

If you fail: You can drive to a pre-booked retest or to a garage for repairs, as long as the failure is not marked dangerous. If it is dangerous, the car must not be driven. Most garages offer a free partial retest within 10 working days if you return to the same station.

What this means if you run a garage

The data points at where the money is:

• Pre-MOT inspections are the most undersold service in the trade. A quarter of all failures are lighting. 2.5 million failures a year are things the driver could have fixed at home. A £30-40 pre-MOT visual check saves the customer a retest fee and earns goodwill that brings them back next year.
• Suspension work is growing. Heavier EVs wear springs and dampers faster, and DVSA data shows suspension climbing the defect rankings year on year. Workshops with alignment rigs are going to see more of this work as the EV fleet ages into its MOT years.
• Older cars are more profitable per test, not less. A 15-year-old car with a 42% failure rate needs more work than a 3-year-old with 13%. The average bill at 6-8 years is already £425. At 10+ it is higher.
• MOT reminders work. 3 million cars are on the road without a valid MOT (Confused.com, DVSA data). That is 3 million tests waiting to be booked. A text message costs less than a penny.

Autera sends MOT reminders automatically to every customer vehicle, with the expiry date pulled straight from DVSA. If you are not reminding customers when their MOT is due, someone else will.

---

Data sources: DVSA annual MOT testing statistics (2024-25), DfT MOT consultation response (January 2024), BookMyGarage MOT invoice analysis (2022-2025), CarcostCheck analysis of 33.2 million first-attempt MOT tests (2025), HiQ Tyres & Autocare regional failure study (May 2025), Confused.com DVSA data analysis (November 2025), RAC Foundation MOT failure research, SMMT new car registration data (2023-2025). Individual test results are available through the DVSA MOT history API at check-mot.service.gov.uk.