MOT fail · manual section 6.2.2

Chassis condition or chassis has excessive corrosion, seriously affecting its strength within 30cm of a body mounting

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 28 September 2026

As a fail, per 100 MOTs (n=130,233,413)0.081

Most often at25 years

Times recorded104,899

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: Chassis condition or chassis corroded within 30cm of a mounting, but not seriously affecting overall security.

The tester looks at the body and underside for corrosion and damage, especially near the points where suspension, steering and seat belts are mounted, and checks the exhaust, fuel system, drive shafts and towbar.

The MOT inspection manual describes the defect (section 6.2.2) as:

Body, cab or chassis excessively corroded at a mounting point

Read this section of the MOT inspection manual on GOV.UK

The DVSA codes counted on this page: the manual item and the defect text as DVSA records them. The heading above joins the two, as a certificate does; the tester also adds the position, such as nearside front.
Result	Manual item	DVSA defect text	Records
Fail Major	Chassis condition	or chassis has excessive corrosion, seriously affecting its strength within 30cm of a body mounting (6.2.2)	104,899

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: 0.87 per 100 MOTs (n=313,355 tests at that age).

Per 100 MOT tests of cars at each age, all makes. We show no figure below 20 tests.
Age	Fail per 100	Tests (n)
7 years	0	10,537,318
8 years	0.001	10,440,457
9 years	0.003	9,949,012
10 years	0.007	9,049,507
11 years	0.017	8,087,514
12 years	0.035	7,303,151
13 years	0.062	6,612,160
14 years	0.10	6,054,526
15 years	0.16	5,591,675
16 years	0.23	4,858,625
17 years	0.31	4,040,458
18 years	0.38	3,261,622
19 years	0.45	2,479,858
20 years	0.50	1,845,952
21 years	0.57	1,321,417
22 years	0.66	913,980
23 years	0.74	619,531
24 years	0.82	428,815
25 years	0.87	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.

Model generations with the highest rate as a fail, against cars of the same ages and fuel. A model’s figure counts this defect only at ages where it is among that model’s 25 most recorded items, and as zero elsewhere, so it is a floor. Tests (n) are all the generation’s MOT tests at ages with at least 1,000 tests each; at least 5,000 in total.
Model	Per 100 MOTs, at least	Same ages and fuel	Times as often	Tests (n)	Ages
Suzuki JimnySuzuki Jimny corrosion welding repair Suzuki Jimny body and structure problems	2.64	0.20	13.3	98,308	3 to 25
Toyota HiluxToyota Hilux corrosion welding repair	0.68	0.14	4.8	278,401	3 to 25
Daihatsu TeriosDaihatsu Terios body and structure problems	1.01	0.21	4.8	14,631	14 to 19
Mitsubishi Shogun SportMitsubishi Shogun Sport body and structure problems	2.41	0.56	4.2	18,439	16 to 21
Ford Ranger	0.38	0.093	4.0	426,542	3 to 24
Kia SorentoKia Sorento corrosion welding repair	0.33	0.095	3.5	147,328	3 to 20
Nissan PathfinderNissan Pathfinder body and structure problems	0.79	0.25	3.1	23,532	10 to 19
Ford TransitFord Transit corrosion welding repair	0.31	0.10	3.0	1,227,954	3 to 25
Suzuki CarrySuzuki Carry body and structure problems	1.07	0.35	3.0	13,545	17 to 22
Suzuki Grand VitaraSuzuki Grand Vitara corrosion welding repair Suzuki Grand Vitara body and structure problems	0.74	0.25	2.9	89,823	9 to 23
Nissan NavaraNissan Navara corrosion welding repair	0.20	0.074	2.7	286,820	3 to 21
Ford KaFord Ka corrosion welding repair Ford Ka body and structure problems	0.15	0.056	2.7	743,190	3 to 23
Isuzu RodeoIsuzu Rodeo body and structure problems	0.76	0.28	2.7	18,681	12 to 19
Toyota PreviaToyota Previa body and structure problems	1.09	0.44	2.4	14,722	17 to 23
Iveco DailyIveco Daily body and structure problems	1.14	0.48	2.3	5,092	16 to 19
Mazda BongoMazda Bongo body and structure problems	0.73	0.32	2.2	35,066	6 to 25
Citroen RelayCitroen Relay corrosion welding repair	0.24	0.13	1.8	57,180	3 to 20
Toyota Land CruiserToyota Land Cruiser body and structure problems	0.93	0.54	1.7	78,269	3 to 25
Ford EscortFord Escort body and structure problems	1.26	0.90	1.3	6,428	22 to 25
Mitsubishi L200	0.20	0.15	1.3	356,000	3 to 23

Read this with care. A fail rate is not a measure of build quality. How far cars are driven, how they are used and how well owners maintain them all change it, and wear items such as tyres and brake pads are common fails. Compare a model only with cars of the same age. Methodology and limits.

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.

Local garage labour, per hour (65 shops)£78

Local garage, middle half£70 to £96

Main dealer labour, per hour (62 shops)£156

Main dealer, middle half£144 to £174

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

Exhaust system has a minor leak of exhaust gases1.92 per 100
Drive shaft constant velocity boot severely deteriorated1.40 per 100
Drive shaft constant velocity boot split or insecure, no longer prevents the ingress of dirt1.35 per 100
Exhaust system mounting defective0.82 per 100
Exhaust system has a major leak of exhaust gases0.75 per 100
Chassis condition is corroded but structural rigidity is not significantly reduced0.38 per 100
Integral vehicle structure condition is corroded but structural rigidity is not significantly reduced0.37 per 100
Exhaust system insecure0.28 per 100
Integral vehicle structure condition corroded to the extent that the rigidity of the assembly is significantly reduced0.13 per 100
Door condition cannot be opened from outside the vehicle0.13 per 100

All body, structure and attachments 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 28 September 2026. Prices updated 22 September 2026.

Not affiliated with or endorsed by DVSA or the Office for National Statistics. How we calculate these figures · Data sources