MOT fail · manual section 5.3.6
Component mounting prescribed area excessively corroded significantly reducing structural strength
What this MOT fail means, how often testers record it and what the usual repair costs. From 130,233,413 DVSA MOT tests taken 2022 to 2025.
MOT data updated
Times recorded adds every DVSA code with this wording, so a test can record it more than once, for example on two wheels under separate codes.
What it means
This is a major defect: the car fails its MOT. A major defect may affect the car’s safety, put other road users at risk or harm the environment. The car fails its MOT and the defect must be repaired.
Before it reaches this point, testers often record it as an advisory: Component mounting prescribed area is corroded but not considered excessive.
Springs, shock absorbers, arms, bushes and ball joints hold each wheel in place and control how it moves. Wear lets a wheel move in ways it should not, and corrosion can weaken springs and mounting points.
The MOT inspection manual describes the defect (section 5.3.6) as:
The strength or continuity of the load bearing structure within 30cm of any sub-frame, spring or suspension component mounting (a 'prescribed area') is significantly reduced or inadequately repaired
Read this section of the MOT inspection manual on GOV.UK
| Result | Manual item | DVSA defect text | Records |
|---|---|---|---|
| Fail Major | Component mounting prescribed areas | prescribed area excessively corroded significantly reducing structural strength (5.3.6) | 635,786 |
Got an MOT advisory or defect on a certificate? Paste it into the MOT advisory checker to see what it means.
How common it is by age
Testers record it most at 25 years: 4.24 per 100 MOTs (n=313,355 tests at that age).
| Age | Fail per 100 | Tests (n) |
|---|---|---|
| 5 years | 0 | 9,425,360 |
| 6 years | 0.001 | 10,382,720 |
| 7 years | 0.002 | 10,537,318 |
| 8 years | 0.005 | 10,440,457 |
| 9 years | 0.013 | 9,949,012 |
| 10 years | 0.037 | 9,049,507 |
| 11 years | 0.10 | 8,087,514 |
| 12 years | 0.22 | 7,303,151 |
| 13 years | 0.41 | 6,612,160 |
| 14 years | 0.75 | 6,054,526 |
| 15 years | 1.11 | 5,591,675 |
| 16 years | 1.54 | 4,858,625 |
| 17 years | 1.93 | 4,040,458 |
| 18 years | 2.25 | 3,261,622 |
| 19 years | 2.57 | 2,479,858 |
| 20 years | 2.85 | 1,845,952 |
| 21 years | 3.16 | 1,321,417 |
| 22 years | 3.49 | 913,980 |
| 23 years | 3.87 | 619,531 |
| 24 years | 4.13 | 428,815 |
| 25 years | 4.24 | 313,355 |
Models that get it most
Each model generation is compared with cars of the same ages and fuel, so older and diesel models are not penalised for their age or fuel. Generations are never pooled.
Repair and cost
The usual repair is corrosion welding repair.
No public source records the price of this whole job, and the time it takes varies from car to car, so we do not publish a single figure. Garages charge by the hour, so ask for a quote that lists labour time and parts. The rates below are what UK garages charge per hour.
Median hourly rate charged for car repairs, from 1,058 local garage and 953 main dealer price quotes collected by the ONS, September 2025 to August 2026. The same shops are priced each month, so the number of shops is the real sample.
Corrosion welding repair: cost and the models that need it more often
Related MOT defects
- Suspension arm pin or bush worn but not resulting in excessive movement4.92 per 100
- Coil spring corroded3.09 per 100
- Shock absorber has light misting of oil2.89 per 100
- Coil spring fractured or broken2.37 per 100
- Sub-frame corroded but not seriously weakened1.89 per 100
- Suspension arm ball joint excessively worn1.41 per 100
- Suspension arm ball joint has slight play1.31 per 100
- Suspension arm pin or bush excessively worn1.19 per 100
- Anti-roll bar linkage ball joint has slight play1.18 per 100
- Suspension arm corroded but not seriously weakened1.08 per 100
All axles, wheels, tyres and suspension defects All MOT defects Car repair costs
Buying a used car?
These figures describe all cars, not any one car. Found one you might buy? See what the VetTheCar Buying Report would tell you.
See an example report MOT fail rates by model All free tools
Source
Contains public sector information licensed under the Open Government Licence v3.0. Source: DVSA anonymised MOT test data, class 4 normal MOT tests, 2022 to 2025, and the MOT inspection manual published on GOV.UK. Prices: ONS consumer price inflation price quotes, September 2025 to August 2026, UK.
MOT data updated . Prices updated .
Not affiliated with or endorsed by DVSA or the Office for National Statistics. How we calculate these figures · Data sources