DVSA MOT defect decoder
Plain English for the code on your MOT fail sheet.
Type or paste any defect code — 1.1.1.a, 5.2.2.c.ii, 8.4.1.a— and we will tell you what it means, how serious it is, and what to do next. Every answer is pinned to the 1 April 2026 revision of the DVSA MOT Inspection Manual on gov.uk.
Codes follow the DVSA MOT Inspection Manual notation: section.subsection.subject.defect.
Browse the manual
Eight sections, by what the tester inspects.
- Section 1140 codes
Brakes
Condition, operation, performance, and parking brake checks.
- Section 275 codes
Steering
Steering control, mechanical condition, power steering and transmission.
- Section 321 codes
Visibility
View of the road, windscreen, mirrors, wipers and washers.
- Section 4104 codes
Lamps & electrical
Headlamps, side and stop lamps, indicators, reflectors, electrical wiring.
- Section 573 codes
Tyres & suspension
Wheels, tyre tread and structure, axles, suspension and shock absorbers.
- Section 688 codes
Body & structure
Body condition, structural integrity, doors, seat belts, fuel system.
- Section 733 codes
Other equipment
Horn, speedometer, registration plates, vehicle identification.
- Section 825 codes
Nuisance & environment
Exhaust emissions, noise, fluid leaks.
Severity by section
Counts from the live corpus.
Common failure categories
One representative defect per section.
1.1.3.a.iiAir and vacuum systemsSection 1: BrakesDangerous2.1.1.b.iiSteering gear conditionSection 2: SteeringDangerous3.1.b.iiField of visionSection 3: VisibilityDangerous4.3.1.a.iiiPresence, condition and operationSection 4: Lamps, reflectors and electrical equipmentDangerous5.1.1.aAxlesSection 5: Axles, wheels, tyres and suspensionDangerous6.1.1.a.iiGeneral conditionSection 6: Body, structure and attachmentsDangerous7.1.1.a.iiSeat belt securitySection 7: Other equipmentDangerous8.1.1.b.iiNoise suppression systemSection 8: NuisanceDangerous
How this works
- 1. Paste the code
From your VT30 failure certificate — any format the tester typed.
- 2. Read the 4-card answer
What the code means, how serious it is, what is actually failing, and what to do next.
- 3. Follow the citation
Every page is pinned to the specific section of the DVSA MOT Inspection Manual on gov.uk so you can cross-check.