Top 10 MOT Failure Points & How to Avoid Them
Every year, millions of UK vehicles fail their MOT. Understanding the most common failure points can help you prepare and potentially save hundreds of pounds in retest fees and emergency repairs.
Looking for your specific car? Check MOT failure rates by make and model for detailed data on 400+ vehicles.
According to DVSA data, approximately one in four vehicles fails its MOT on the first attempt. That is roughly 7.5 million failures each year across the UK. However, a large proportion of these are for relatively minor, preventable issues. By understanding where failures concentrate, you can focus your preparation on the areas that matter most.
1. Lights and Signalling
The single biggest cause of MOT failures. Includes blown bulbs, faulty indicators, and misaligned headlights.
Prevention: Walk around your car weekly and check all lights work. Keep spare bulbs in your glovebox.
Failure by age: Lighting failures are relatively consistent across all vehicle ages, though cars over 10 years old see a slight increase due to corroded bulb holders and degraded wiring. The Ford Fiesta (Mk7 and Mk7.5) and Vauxhall Corsa (Corsa D) are particularly susceptible to rear light cluster failures due to known design issues with moisture ingress.
Typical fix cost: Bulb replacement costs two to eight pounds. A full headlight unit ranges from thirty to one hundred and fifty pounds depending on the model. Headlight alignment adjustment at a garage costs around twenty to thirty pounds.
2. Suspension
Worn shock absorbers, damaged springs, and deteriorated bushes. Often develops gradually so drivers don't notice.
Prevention: Listen for knocking sounds over bumps. If the car bounces more than twice when you push down on each corner, shocks may be worn.
Failure by age: Suspension failures increase significantly with age. Vehicles under 5 years old rarely fail on suspension, but by 10 years the rate climbs sharply. Cars driven frequently on poor road surfaces (rural areas, cities with potholes) are disproportionately affected. The Peugeot 207 and Renault Megane have notably high suspension failure rates compared to their competitors, particularly for front lower arm bushes and anti-roll bar links.
Typical fix cost: Anti-roll bar drop links cost thirty to sixty pounds per pair fitted. Shock absorbers range from one hundred to three hundred pounds per pair including fitting. Spring replacement typically costs one hundred to two hundred pounds per corner.
3. Brakes
Worn pads and discs, corroded lines, and seized callipers. Critical safety system that testers examine thoroughly.
Prevention: Replace pads before they reach minimum thickness. Address any squealing or grinding immediately.
Failure by age: Brake failures rise steadily with mileage rather than age per se, though the two are correlated. Vehicles covering high annual mileages (above 15,000 miles) are more likely to need brake work before their MOT. Diesel vehicles tend to have slightly higher brake failure rates because their engine braking is less pronounced, leading to more reliance on the friction brakes. Models like the Ford Transit and other commercial vehicles have elevated brake failure rates due to heavy loads and stop-start driving.
Typical fix cost: Front brake pads cost forty to eighty pounds fitted. Pads and discs together typically run one hundred and fifty to three hundred pounds per axle. Corroded brake lines can cost one hundred to two hundred pounds to replace.
4. Tyres
Insufficient tread depth, damage to sidewalls, and incorrect tyre types. Legal minimum tread is 1.6mm.
Prevention: Check tread monthly with a 20p coin. If you see the outer band, tyres need replacing.
Failure by age: Tyre failures are driven more by mileage and driving style than vehicle age. However, very old tyres (over 5 to 6 years) develop cracking in the rubber compound even with adequate tread, and testers will flag this. SUVs and larger vehicles like the Nissan Qashqai and Ford Kuga wear tyres faster due to their weight, and uneven wear caused by poor alignment is a common issue on these models.
Typical fix cost: Budget tyres start from forty pounds each fitted, with mid-range options at sixty to ninety pounds. Premium brands cost one hundred to one hundred and fifty pounds per tyre. Wheel alignment costs thirty to fifty pounds and can dramatically extend tyre life.
5. Driver's View
Windscreen damage, worn wipers, and obstructions. Chips in the driver's central view are automatic failures.
Prevention: Get windscreen chips repaired early — they spread over time. Replace wipers annually.
Failure by age: Windscreen failures are relatively age-independent since stone chips can happen to any vehicle. However, older vehicles are more likely to have accumulated multiple chips or developed cracks that have spread. Vehicles driven frequently on motorways are at higher risk. Wiper-related failures increase with age as rubber degrades, with most failures occurring on vehicles that have not had blades replaced for two or more years.
Typical fix cost: Windscreen chip repair is often free through car insurance. Wiper blades cost eight to twenty pounds per pair. Full windscreen replacement ranges from one hundred and fifty to five hundred pounds depending on the vehicle, though this is usually covered by insurance with an excess.
6. Steering
Worn components, excessive play in the wheel, and power steering issues.
Prevention: Note any wandering, vibration, or difficulty steering. Get checked if steering feels different.
Failure by age: Steering failures become significantly more common after 8 to 10 years. Power steering pump failures and rack wear are the most common issues on older vehicles. Vehicles with electric power steering (most cars built after 2010) tend to have fewer mechanical steering failures but can develop sensor issues. The Vauxhall Astra H and Ford Focus Mk2 have notably high steering component wear rates.
Typical fix cost: Track rod ends cost fifty to one hundred pounds per side fitted. Power steering pump replacement ranges from two hundred to five hundred pounds. A full steering rack is a major expense at five hundred to one thousand pounds or more.
7. Exhaust and Emissions
Failed catalytic converters, exhaust leaks, and high emissions readings.
Prevention: A 20-minute motorway drive before the test helps the catalytic converter reach optimal temperature.
Failure by age: Emissions failures increase sharply for vehicles over 8 years old, particularly diesels. The introduction of stricter emissions standards in 2018 hit older diesel vehicles hardest, with DPF-related failures becoming a major issue. Vehicles that are primarily used for short urban journeys are at the highest risk because the DPF and catalytic converter never reach the temperatures needed for regeneration. The Volkswagen Golf TDI and BMW 3 Series diesel are common offenders for DPF-related failures.
Typical fix cost: An exhaust flexi-pipe repair costs sixty to one hundred and fifty pounds. Catalytic converter replacement ranges from two hundred to eight hundred pounds. DPF cleaning costs one hundred to three hundred pounds, while DPF replacement can cost five hundred to two thousand pounds.
8. Body and Structure
Excessive corrosion, sharp edges, and structural damage that could be dangerous.
Prevention: Check underneath for rust, especially on older vehicles. Treat any corrosion early.
Failure by age: Body and structure failures are heavily age-dependent and are the category most affected by vehicle age. Cars over 12 years old are dramatically more likely to fail on corrosion, particularly in coastal areas and regions where road salt is heavily used (Scotland, northern England, Wales). Sill corrosion, subframe rust, and floor pan deterioration are the most common structural issues. Japanese imports and vehicles from brands like Mazda, particularly older models, have historically higher corrosion rates in the UK climate.
Typical fix cost: Minor corrosion repair and welding costs fifty to two hundred pounds. Sill replacement ranges from two hundred to six hundred pounds per side. Subframe repair or replacement can cost five hundred to one thousand five hundred pounds, often making it uneconomical on older vehicles.
9. Fuel System
Leaks, damaged fuel caps, and insecure fuel tanks.
Prevention: Check for fuel smells and ensure your fuel cap seals properly.
Failure by age: Fuel system failures are relatively uncommon on vehicles under 10 years old. On older vehicles, fuel line corrosion and degraded rubber hoses are the primary concerns. The fuel filler cap seal is the most commonly failed item in this category and costs very little to replace. Vehicles stored outdoors are more susceptible to fuel system corrosion than those kept in garages.
Typical fix cost: A replacement fuel cap costs ten to thirty pounds. Fuel line repair ranges from fifty to two hundred pounds depending on the location and complexity. Fuel tank repairs or replacement can cost two hundred to six hundred pounds.
10. Seatbelts
Frayed webbing, faulty buckles, and retractor issues.
Prevention: Test all seatbelts monthly — they should lock when tugged sharply and retract smoothly.
Failure by age: Seatbelt failures increase gradually with age but are also affected by usage patterns. Family cars with children tend to have more seatbelt issues, with buckle mechanisms becoming clogged with debris. The retractor mechanism can weaken over time, causing the belt to lock inconsistently. Vehicles over 15 years old may also show webbing degradation, particularly if exposed to prolonged sunlight through the windows.
Typical fix cost: Seatbelt buckle replacement costs forty to eighty pounds per belt. A full seatbelt assembly replacement ranges from one hundred to two hundred and fifty pounds per belt. Retractor repairs are similar in cost as the entire unit typically needs replacing.
Summary: All 10 Failure Points at a Glance
| Rank | Failure Point | % of Failures | Avg Fix Cost | DIY Possible? |
|---|---|---|---|---|
| 1 | Lights & Signalling | 18% | £2 – £150 | Yes (bulbs) |
| 2 | Suspension | 12% | £30 – £300 | Limited |
| 3 | Brakes | 10% | £40 – £300 | Limited |
| 4 | Tyres | 9% | £40 – £150/tyre | No (fitting) |
| 5 | Driver's View | 8% | £8 – £500 | Yes (wipers) |
| 6 | Steering | 7% | £50 – £1,000 | No |
| 7 | Exhaust & Emissions | 6% | £60 – £2,000 | No |
| 8 | Body & Structure | 5% | £50 – £1,500 | No |
| 9 | Fuel System | 4% | £10 – £600 | Partial |
| 10 | Seatbelts | 3% | £40 – £250 | No |
See Your Vehicle's Specific Risk Profile
Our AI analyses your vehicle's make, model, age, and history to predict which components are most likely to fail.
Check Your MOT Risk FreeHow Failure Rates Change With Vehicle Age
The relationship between vehicle age and MOT failure is not linear. Understanding how it evolves can help you anticipate problems at different stages of your car's life.
3 to 5 years (first MOT window): Vehicles in this age range have an overall failure rate of around 15%. The most common failures are lighting faults (often caused by LED or DRL issues on modern cars), tyre wear, and windscreen chips. Suspension and corrosion are extremely rare at this stage. Many first-time MOT failures are for simple oversights that owners of newer cars simply haven't thought to check.
6 to 10 years: Failure rates climb to around 18%. Brakes and suspension start to feature more prominently as components reach the end of their first lifecycle. This is the age range where neglected maintenance begins to show. Advisory items from previous MOTs that were never addressed often graduate to failure items. Emissions issues also begin to appear, particularly on diesel vehicles where the DPF has been subjected to years of short journeys.
10 to 15 years: The failure rate peaks at approximately 20%. Corrosion and structural issues become significant for the first time. Suspension and steering component wear accelerates, and many vehicles need major work to remain MOT-compliant. This is the age range where the cost of MOT-related repairs most often prompts owners to consider scrapping rather than repairing.
15+ years: Interestingly, the failure rate plateaus or even dips slightly to around 19%. This is a survivorship effect — vehicles that have lasted this long are typically well-maintained by enthusiast or careful owners. The poorly maintained examples have already been scrapped. Corrosion remains the biggest threat, and structural welding repairs become increasingly common.
MOT Failures by Car Type
Different types of vehicles have different failure profiles, driven by their weight, typical usage patterns, and mechanical complexity.
- Hatchbacks (e.g., Ford Fiesta, Vauxhall Corsa, VW Polo): Hatchbacks generally have slightly lower failure rates than larger vehicles. Their lighter weight puts less stress on suspension, brakes, and tyres. However, they are often used as first cars or city runabouts, meaning they may receive less attentive maintenance. Common failures are lights, wipers, and tyres.
- SUVs and crossovers (e.g., Nissan Qashqai, Ford Kuga, Hyundai Tucson): SUVs have higher tyre and brake wear due to their weight. Suspension failures are also more common as the heavier body puts additional strain on bushes and dampers. However, because many SUVs are relatively new on UK roads, their average age is younger, which partially offsets these mechanical disadvantages.
- Estates and saloons (e.g., Ford Mondeo, VW Passat, BMW 3 Series): Often used as company cars and for longer journeys, estates and saloons accumulate higher mileages. This increases brake and tyre wear but also means the catalytic converter and DPF are more likely to stay in good condition due to regular motorway driving. Corrosion can be an issue on older examples, particularly around the rear wheel arches.
- Vans and commercial vehicles (e.g., Ford Transit, VW Transporter, Vauxhall Vivaro): Vans have the highest average failure rates of any vehicle type. Heavy loads, hard use, and high mileages all contribute. Brake failures are disproportionately high, as are suspension and corrosion issues. Tyre wear is also accelerated by frequent heavy loading. Many van owners defer maintenance due to commercial pressures, compounding the problem.
How to Use This Data
Knowing the top failure points is useful, but the real value comes from applying this knowledge to your specific vehicle. Here is how to make this data work for you:
- Check your previous advisories: Your last MOT certificate lists advisory items that were noted but did not cause a failure. These are your strongest signal of what might fail next time. If your last test had a "brake disc worn but above limit" advisory, you can be confident that brakes should be your top priority before the next test.
- Consider your vehicle's profile: Use the age and type breakdowns above to identify which categories are most relevant to your car. A 12-year-old hatchback should focus on corrosion and suspension, while a 5-year-old SUV should check tyres and brakes.
- Use AutoSafe for personalised data: AutoSafe's prediction tool combines all of these factors — your vehicle's make, model, age, mileage, and full MOT history — to produce a personalised risk score and component-level breakdown. This is the most targeted way to prepare for your MOT.
- Act on the data early: Book your MOT 2 to 4 weeks before the expiry date. This gives you time to address any failures without the stress of an expired certificate. If you know your vehicle is likely to need work, get a pre-MOT inspection done at a local garage to identify issues before the official test.
Frequently Asked Questions
What is the most common reason for MOT failure?
The most common reason for MOT failure is lighting and signalling faults, which account for approximately 18% of all failures. This includes blown bulbs, misaligned headlights, faulty indicators, and broken number plate lights. Lighting issues are also among the cheapest and easiest problems to fix, often costing under ten pounds for a replacement bulb.
What percentage of cars fail their MOT?
Approximately 25% of vehicles fail their MOT on the first attempt each year in the UK. However, this figure varies significantly depending on the vehicle's age, make, model, and how well it has been maintained. Newer vehicles aged 3 to 5 years have a failure rate of around 15%, while vehicles aged 10 to 15 years fail around 20% of the time. Some individual models have failure rates above 35%.
What are the top 10 MOT failures?
The top 10 MOT failure points in order are: 1) Lights and signalling (18%), 2) Suspension (12%), 3) Brakes (10%), 4) Tyres (9%), 5) Driver's view including windscreen and wipers (8%), 6) Steering (7%), 7) Exhaust and emissions (6%), 8) Body and structure (5%), 9) Fuel system (4%), and 10) Seatbelts (3%). Together, these account for the vast majority of all MOT failures in the UK.
Do older cars fail MOT more often?
Yes, older cars generally fail their MOT more frequently. Vehicles aged 3 to 5 years have a failure rate of around 15%, which rises to 18% for 6 to 10 year old vehicles and approximately 20% for vehicles aged 10 to 15 years. However, very old vehicles (15 years and above) sometimes show a slight decrease because the ones still on the road tend to be well-maintained by dedicated owners. The types of failures also change with age, with older cars more prone to corrosion and suspension wear, while newer vehicles are more likely to fail on electronics and lighting.
How can I avoid failing my MOT?
To avoid failing your MOT, perform a pre-MOT checklist covering lights, tyres, wipers, windscreen, seatbelts, and fluid levels. Address any advisories from your previous MOT, as these are the strongest predictor of future failures. Drive the car for 20 minutes on a motorway before the test to warm the catalytic converter and DPF. Use a tool like AutoSafe to check your vehicle's specific risk profile based on its make, model, age, and history. Finally, book your MOT 2 to 4 weeks before the expiry date so you have time to fix any issues if needed.
Can I fix MOT failures myself?
Many common MOT failures can be fixed at home without specialist tools. Blown bulbs, worn wiper blades, low washer fluid, and underinflated tyres are all simple DIY fixes. Even replacing a number plate light or topping up brake fluid is straightforward for most people. However, more complex repairs such as brake pad replacement, suspension work, or exhaust repairs are best left to a qualified mechanic unless you have experience and the proper tools.