What does 4.1.2 mean on an MOT certificate?

It refers to sub-section 4.1.2 of the MOT inspection manual, "Headlamp alignment", within section 4, lamps, reflectors and electrical equipment. The letter or letters after it — (a), (b)(i) and so on — identify the specific defect from the 3 listed here. 3 Major and 0 Minor.

Which headlamp alignment defect is recorded most often?

"The aim of a headlamp is not within limits laid down in the requirements" (4.1.2 (a)), recorded about 9.0 times per 100 failed MOT tests nationally. We explain what it means and what puts it right.

Does a Minor defect fail the MOT?

No. a defect with no significant effect on safety or the environment. Recorded on the certificate; the vehicle passes. Major and Dangerous defects fail. A Dangerous defect also means the car must not be driven until it is repaired.

Section 4 · Lamps, reflectors and electrical equipment

4.1.2 Headlamp alignment

Manual indexed 3 September 2026

Quick answer

Sub-section 4.1.2 of the MOT inspection manual covers headlamp alignment and lists 3 defects. A reference like "(4.1.2 (a))" on a certificate points to the matching row below. The most recorded is "The aim of a headlamp is not within limits laid down in the requirements", about 9.0 times per 100 failed tests.

Official wording

The defect clauses

4.1.2 (a)Major9.0 per 100 fails
The aim of a headlamp is not within limits laid down in the requirements
Headlamp aim incorrect explained: what it means and what puts it right
4.1.2 (b)Major0.6 per 100 fails
Headlamp aim unable to be tested
Headlamp aim incorrect explained: what it means and what puts it right
4.1.2 (c)Major
Beam image obviously incorrect

Wording and categories reproduced from the DVSA inspection manual under the Open Government Licence. Frequencies are items per 100 failed class 4 tests across the DVSA anonymised MOT dataset; a clause with no figure was not recorded often enough to appear in any model’s top forty failure items. 2 of 3 clauses link to our own explanation.

Grading

What the categories mean

Dangerous: a direct and immediate risk to road safety or the environment. The vehicle fails and must not be driven until repaired, even to a garage.
Major: a defect that affects safety, the environment or other road users. The vehicle fails.
Minor: a defect with no significant effect on safety or the environment. Recorded on the certificate; the vehicle passes.

The full guide to defect grading

Section 4

Other sub-sections of lamps, reflectors and electrical equipment

All sections of the manual

Common questions

What does 4.1.2 mean on an MOT certificate?: It refers to sub-section 4.1.2 of the MOT inspection manual, "Headlamp alignment", within section 4, lamps, reflectors and electrical equipment. The letter or letters after it — (a), (b)(i) and so on — identify the specific defect from the 3 listed here. 3 Major and 0 Minor.
Which headlamp alignment defect is recorded most often?: "The aim of a headlamp is not within limits laid down in the requirements" (4.1.2 (a)), recorded about 9.0 times per 100 failed MOT tests nationally. We explain what it means and what puts it right.
Does a Minor defect fail the MOT?: No. a defect with no significant effect on safety or the environment. Recorded on the certificate; the vehicle passes. Major and Dangerous defects fail. A Dangerous defect also means the car must not be driven until it is repaired.