MOT advisory “Non-component advisories Mudguard insecure” — meaning and what to do

Last updated · OBDCode UK editorial

In plain English: the tester noted a non-component item that was not a fail on that MOT. Fix soon.

This advisory means the tester found non-component advisories that was mudguard insecure — not judged bad enough to fail that recorded test, but noted for attention. It was recorded 3,300 times on UK Class 4 MOT certificates in 2025 (about #161 in this dataset).
Fix soon What to do about timing
3,300Times recorded in 2025
AdvisoryDid not fail that test

Can you drive with this?

Drive with care. This advisory alone does not normally mean you must stop driving. Still plan the repair before the next MOT so it does not become a fail.

12V electrical safety. On a 12V battery: disconnect negative first, reconnect negative last. Prevent sparks and short circuits. Stop if the battery is damaged or sits near orange high-voltage cables.

What the tester saw

MOT testers work from the DVSA inspection manual. For this item the manual wording is “Mudguard insecure”. In plain English: the tester judged that wear or deterioration on the non-component advisories had not gone far enough to reject at that test. That is why it was recorded as an advisory rather than a failure. It is not a statement about the vehicle’s condition or legal status today.

Do you need to fix it?

An advisory did not affect that test’s result. It is the tester telling you what is likely to need attention, and how soon depends on the item.

  • Fix soon. An insecure mudguard should be refitted within a few weeks before it tears free. Book sooner if it flaps at speed, scrapes the tyre, or hangs low.
  • Can you DIY? Basic external checks may be suitable for a careful DIY driver with household tools, on firm level ground. We do not publish strip-down or fitting steps here.
  • 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.

What happened to other cars with this advisory

Of the 506 cars that passed their 2024 MOT with this advisory, none failed on that same item the following year.

These figures are a statistical association from the national MOT extracts. They are not a prediction about this car, and we have not inspected it.

Their rate of failing a 2025 MOT for any reason was 21.7% (95% CI 18.4–25.5), against 18.2% (95% CI 18.2–18.2) for cars that passed without this advisory.

The same 506 cars were 12.5 percentage points more likely not to be tested again in 2025 (19.8% (95% CI 16.5–23.5) versus 7.3% (95% CI 7.3–7.3) for cars without the advisory). The extracts do not record scrappage; a missing later test is the public signal that the vehicle was not presented.

The median car in this cohort was 12.0 years old with 89,438 miles at the 2024 test.

Follow-up uses the DVSA vehicle_id, which is stable across annual releases, so the same physical car is compared from its 2024 test to its 2025 test. Browse the MOT prognosis registry. Source: DVSA Anonymised MOT tests and results, 2024 and 2025 extracts (Class 4). Contains public sector information licensed under the Open Government Licence v3.0.

Related non-component advisories advisories

Before you agree to the work

A fault or an advisory is a quote waiting to happen. These pages set out what a garage has to tell you, what a comparable written quote should include, and what you can do if the bill is not what you agreed.

Frequency: DVSA Anonymised MOT tests and results, 2025 extract (Class 4). Wording follows the DVSA inspection manual. Contains public sector information licensed under the Open Government Licence v3.0.