MOT advisory · manual section 6.1.1

Chassis condition is corroded but structural rigidity is not significantly reduced

What this MOT advisory 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 an advisory, per 100 MOTs (n=130,233,413)0.38

Most often at25 years

Times recorded497,970

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 an advisory: the car passes its MOT, and the tester is warning about the part. An advisory is something the tester noticed that could become a defect later. The car passes its MOT. The advice is to monitor the part and repair it if it gets worse.

When it gets worse, the tester records it as a fail: Chassis condition corroded to the extent that the rigidity of the assembly is significantly reduced.

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 tester fails the car when the part reaches the point the MOT inspection manual describes (section 6.1.1):

Vehicle structure corroded to the extent that the rigidity of the assembly is seriously reduced

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
Advisory	Chassis condition	is corroded but structural rigidity is not significantly reduced (6.1.1)	497,970

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: 2.84 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	Advisory per 100	Tests (n)
3 years	0	8,016,463
4 years	0.001	8,699,937
5 years	0.003	9,425,360
6 years	0.008	10,382,720
7 years	0.017	10,537,318
8 years	0.036	10,440,457
9 years	0.065	9,949,012
10 years	0.11	9,049,507
11 years	0.19	8,087,514
12 years	0.31	7,303,151
13 years	0.46	6,612,160
14 years	0.65	6,054,526
15 years	0.86	5,591,675
16 years	1.09	4,858,625
17 years	1.34	4,040,458
18 years	1.55	3,261,622
19 years	1.77	2,479,858
20 years	1.91	1,845,952
21 years	2.03	1,321,417
22 years	2.16	913,980
23 years	2.42	619,531
24 years	2.65	428,815
25 years	2.84	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 an advisory, 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
Isuzu TFIsuzu TF body and structure problems	7.17	0.54	13.2	6,237	11 to 14
Isuzu D-Max	0.67	0.072	9.2	134,777	3 to 13
Toyota HiluxToyota Hilux corrosion welding repair	4.37	0.63	6.9	278,401	3 to 25
Nissan NavaraNissan Navara corrosion welding repair	2.73	0.39	6.9	286,820	3 to 21
Nissan PathfinderNissan Pathfinder body and structure problems	8.52	1.26	6.7	23,532	10 to 19
Mitsubishi L200	4.60	0.70	6.5	356,000	3 to 23
Isuzu RodeoIsuzu Rodeo body and structure problems	8.91	1.40	6.3	18,681	12 to 19
Ford Ranger	2.23	0.42	5.2	426,542	3 to 24
Suzuki JimnySuzuki Jimny corrosion welding repair Suzuki Jimny body and structure problems	3.72	0.73	5.0	98,308	3 to 25
Mitsubishi Shogun SportMitsubishi Shogun Sport body and structure problems	10.9	2.34	4.6	18,439	16 to 21
Mazda 5Mazda 5 body and structure problems	2.57	0.57	4.5	44,929	8 to 18
Daihatsu TeriosDaihatsu Terios body and structure problems	3.66	0.85	4.2	14,631	14 to 19
Ford TransitFord Transit corrosion welding repair	2.19	0.51	4.2	1,227,954	3 to 25
Iveco DailyIveco Daily body and structure problems	8.72	2.13	4.0	5,092	16 to 19
Suzuki CarrySuzuki Carry body and structure problems	4.73	1.27	3.7	13,545	17 to 22
Suzuki Grand VitaraSuzuki Grand Vitara corrosion welding repair Suzuki Grand Vitara body and structure problems	3.53	1.03	3.4	89,823	9 to 23
Land Rover DiscoveryLand Rover Discovery body and structure problems	3.88	1.18	3.2	591,956	3 to 25
Land Rover Range Rover Sport	1.25	0.42	2.9	498,033	3 to 20
Mazda BongoMazda Bongo body and structure problems	3.68	1.29	2.8	35,066	6 to 25
Toyota Land CruiserToyota Land Cruiser body and structure problems	5.22	2.06	2.5	78,269	3 to 25

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
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
Sub-frame is corroded but structural rigidity is not significantly reduced0.12 per 100

All body, structure and attachments defects All MOT defects Car repair costs

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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