What does 6.1.3 mean on an MOT certificate?

It refers to sub-section 6.1.3 of the MOT inspection manual, "Fuel system", within section 6, body, structure and attachments. The letter or letters after it — (a), (b)(i) and so on — identify the specific defect from the 8 listed here. 4 of them are graded Dangerous, 3 Major and 1 Minor.

Which fuel system defect is recorded most often?

"Fuel system leaking, or missing or ineffective filler cap" (6.1.3 (b)(i)), recorded about 0.1 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 6 · Body, structure and attachments

6.1.3 Fuel system

Manual indexed 3 September 2026

Quick answer

Sub-section 6.1.3 of the MOT inspection manual covers fuel system and lists 8 defects, 4 of them Dangerous. A reference like "(6.1.3 (a)(i))" on a certificate points to the matching row below. The most recorded is "Fuel system leaking, or missing or ineffective filler cap", about 0.1 times per 100 failed tests.

Official wording

The defect clauses

6.1.3 (a)(i)Majorunder 0.1 per 100 fails
Fuel tank, pipe or hose insecure
Fuel filler cap missing or fuel system leaking explained: what it means and what puts it right
6.1.3 (a)(ii)Dangerous
Fuel tank, pipe or hose insecure such that there is a risk of fire
Fuel filler cap missing or fuel system leaking explained: what it means and what puts it right
6.1.3 (b)(i)Major0.1 per 100 fails
Fuel system leaking, or missing or ineffective filler cap
Fuel filler cap missing or fuel system leaking explained: what it means and what puts it right
6.1.3 (b)(ii)Dangerousunder 0.1 per 100 fails
Fuel system leaking excessively or a risk of fire
Fuel filler cap missing or fuel system leaking explained: what it means and what puts it right
6.1.3 (c)(i)Minor
Fuel pipe or hose chafing
Fuel filler cap missing or fuel system leaking explained: what it means and what puts it right
6.1.3 (c)(ii)Majorunder 0.1 per 100 fails
Fuel pipe or hose damaged
Fuel filler cap missing or fuel system leaking explained: what it means and what puts it right
6.1.3 (e)Dangerousunder 0.1 per 100 fails
Fire risk due to fuel tank shield or exhaust shield missing where fitted as original equipment
Fuel filler cap missing or fuel system leaking explained: what it means and what puts it right
6.1.3 (f)Dangerous
Any part of an LPG/CNG/LNG or hydrogen system defective

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. 7 of 8 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 6

Other sub-sections of body, structure and attachments

6.1.1General condition
6.1.2Exhaust system
6.1.4Bumpers
6.1.5Spare wheel carrier (if fitted)
6.1.6Coupling mechanisms and towing equipment
6.1.7Transmission
6.1.8Engine mountings
6.2.1Body condition
6.2.2Cab and body mounting
6.2.3Doors and door catches
6.2.4Floor
6.2.5Driver’s seat
6.2.6Passenger seats
6.2.7Driving controls
6.2.8Cab steps (if fitted)
6.2.12Handgrips and footrests

All sections of the manual

Common questions

What does 6.1.3 mean on an MOT certificate?: It refers to sub-section 6.1.3 of the MOT inspection manual, "Fuel system", within section 6, body, structure and attachments. The letter or letters after it — (a), (b)(i) and so on — identify the specific defect from the 8 listed here. 4 of them are graded Dangerous, 3 Major and 1 Minor.
Which fuel system defect is recorded most often?: "Fuel system leaking, or missing or ineffective filler cap" (6.1.3 (b)(i)), recorded about 0.1 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.