MOT advisory “Prescribed areas or chassis corroded within 30cm of a mounting, but not seriously affecting overall security” — meaning and what to do
What the tester saw
MOT testers work from the DVSA inspection manual. For this item the manual wording is “Body, cab or chassis excessively corroded at a mounting point”. In plain English: there is wear or deterioration on the prescribed areas that is currently within legal limits (defect category: Major). The tester is flagging it so you can plan the repair before it becomes a fail — or a roadside problem.
Do you need to fix it?
Not to stay legal today — an advisory does not affect the pass. But advisories are the tester telling you what will likely fail next time. Two sensible rules:
- Safety-critical systems first. Body, chassis, structure advisories are usually less urgent, but get a quote now so the cost doesn’t surprise you later.
- Buying a used car? Repeated advisories for the same item across several years of MOT history mean the owner has been ignoring it. Check the car’s full record with our free MOT history check.
Typical repair cost
Surface corrosion treated early is cheap; structural welding starts around £150 per area and climbs quickly. Get corrosion advisories inspected before winter.
Rule out related electronic faults yourself — a scan takes two minutes and saves a diagnostic fee.
- Topdon OBD2 scannersTopdon diagnostic scanners with full-system readouts
- XTOOL diagnostic toolsXTOOL code readers for petrol and diesel cars
- Autel UK testersAutel professional-grade diagnostic testers
Related body, chassis, structure advisories
FAQs
Will “or chassis corroded within 30cm of a mounting, but not seriously affecting overall security” fail my next MOT?
Not automatically — it fails only when the wear crosses the legal threshold in the inspection manual. But this advisory is the most common precursor: if left unattended, expect it to become a Minor or Major defect at a future test.
Can I ask the garage to remove an advisory?
No. Advisories are part of the official test record held by DVSA and appear in the vehicle’s public MOT history. Fixing the item means it simply won’t be advised next time.
Does an advisory affect the car’s value?
Slightly, yes — buyers who check MOT history (which is free) will price in the pending repair. Fixing cheap advisories before selling usually pays for itself.
Frequency: DVSA anonymised MOT data, 2025 (Class 4). Wording follows the DVSA inspection manual. Contains public sector information licensed under OGL v3.0.