Every year, millions of UK drivers take their car for an MOT without really knowing what the tester is looking for. Understanding what an MOT test checks helps you prepare your vehicle, avoid unnecessary failures, and make informed decisions about repairs. This guide covers the complete MOT checklist — every system the tester inspects, what they are looking for, and how to check the key items yourself before your test.
What Is the MOT Test Checklist?
The MOT test is carried out against a fixed DVSA checklist. Every authorised test centre in the UK uses the same checklist — the tester cannot add or skip items. The checklist covers over 40 individual components across 10 main systems.
Faults are categorised into three levels:
- Dangerous — an immediate risk to road safety or the environment. The car cannot be driven from the test centre until repaired.
- Major — a significant fault that means the car fails. Must be repaired before a certificate is issued.
- Minor — a defect noted but not serious enough to fail. Recorded as an advisory. Should be monitored and repaired before the next test.
Here is what the MOT test checks, system by system.
1. Lights and Signals
All external lights are checked for function, alignment, and condition.
What is tested:
- Headlights (main beam and dipped beam) — must work and be correctly aligned
- Brake lights — all must illuminate when the brake pedal is pressed
- Indicators (front, rear, and side) — must flash at the correct rate
- Hazard lights
- Fog lights (front and rear)
- Number plate light — must illuminate the plate clearly
- Reversing lights (advisory if not working on older vehicles)
- Daytime running lights (DRLs) on vehicles fitted with them
Common failures: Blown bulbs, cracked lenses, misaligned headlights, non-functioning fog lights.
Check yourself: Walk around the car with someone helping you test each light in turn. Check headlight beam pattern at night against a flat wall — both beams should be the same height.
2. Tyres
Tyres are one of the most common MOT failure points in the UK.
What is tested:
- Tread depth — minimum legal limit is 1.6mm across the central three-quarters of the tyre
- Tyre condition — cuts, bulges, exposed cords, and uneven wear are all fail items
- Tyre size — all tyres must be the correct size for the vehicle
- Tyre inflation — severely under or over-inflated tyres may be noted
- Spare tyre — not tested, but a temporary spare must be roadworthy if fitted
Common failures: Tread below 1.6mm (often on rear tyres where wear is less obvious), sidewall damage, mismatched tyre sizes.
Check yourself: Use a 20p coin inserted into the tread groove — if the outer band of the coin is visible, your tread is at or below the legal limit and the tyre will fail. Check all four tyres including the inner edges.
3. Brakes
The brake system receives one of the most thorough inspections in the MOT test.
What is tested:
- Brake pedal condition and feel
- Brake pad and disc condition — thickness and wear
- Brake drums and shoes (on older vehicles)
- Brake lines and pipes — for leaks, corrosion, or damage
- Handbrake / electronic parking brake — must hold the vehicle on a slope
- Brake fluid level — may be checked visually
- Brake performance — measured on a rolling road brake tester at most centres
Common failures: Worn brake pads below minimum thickness, corroded or scored discs, seized callipers causing uneven braking, handbrake not holding.
Check yourself: Press the brake pedal — it should feel firm, not spongy. The car should not pull to one side when braking. Check for a grinding or squealing noise which indicates worn pads.
4. Steering and Suspension
What is tested:
- Steering wheel — play (excessive movement before wheels respond), condition, and security
- Power steering — fluid level and system function
- Steering column, rack, and joints — checked for wear and play
- Shock absorbers — bounce test and visual inspection for leaks
- Springs — condition and security
- Wheel bearings — checked for play and noise
- CV joints and driveshafts — for wear or damage (split boots noted as advisory)
Common failures: Excessive steering play, worn shock absorbers, failed wheel bearings, worn CV joint boots (major if split and leaking grease).
Check yourself: While stationary, rock the steering wheel gently — there should be minimal play before resistance is felt. Bounce each corner of the car — it should settle after one or two bounces, not continue bouncing.
5. Exhaust and Emissions
What is tested:
- Exhaust system — security, leaks, and general condition
- Exhaust noise — excessive noise can be a failure
- Emissions — tested using a probe inserted into the exhaust
- Petrol engines: Carbon monoxide (CO) and hydrocarbon (HC) levels must be within limits
- Diesel engines: Smoke opacity test — the engine is revved and smoke density is measured
- Catalytic converter — must be present and functioning on vehicles fitted with one
Common failures: Blowing exhaust joints, excessive diesel smoke (often caused by injector or DPF issues), failing emissions on a poorly maintained petrol engine, missing catalytic converter.
Check yourself: Start the engine and check for any rattling from the exhaust, blue smoke (oil burning), black smoke (diesel/rich mixture), or excessive noise.
6. Windscreen, Wipers, and Washers
What is tested:
- Windscreen — must have no damage in the driver’s critical zone (a 290mm wide band in front of the driver). Chips or cracks larger than 10mm in this zone are a major failure.
- Wipers — must clear the windscreen effectively without smearing
- Washer system — must spray fluid and the reservoir must not be empty
- Rear window — must be clear (heated element checked on heated rear windscreens)
Common failures: Chips or cracks in the driver’s line of sight, smearing wiper blades, empty screenwash reservoir (automatic failure).
Check yourself: Inspect the windscreen directly in front of the driver’s seat. Fill the screenwash reservoir. Replace wiper blades if they smear — they are inexpensive and an easy fix before your test.
7. Seatbelts
What is tested:
- All seatbelts fitted to the vehicle — front and rear
- Belt condition — cuts, fraying, or damage
- Buckle function — must latch and release correctly
- Retractor function — belt should retract smoothly and lock under sharp pull
- Mounting points — checked for security and corrosion
Common failures: Belts that do not retract, damaged or frayed webbing, sticky or non-locking buckles.
Check yourself: Pull each belt sharply — it should lock immediately. Release and check it retracts fully. Check the buckle clicks and releases cleanly.
8. Fuel System
What is tested:
- Fuel tank — security and condition
- Fuel pipes and connections — for leaks or damage
- Fuel cap — must seal correctly
Common failures: Fuel leaks, loose or damaged fuel cap, corroded fuel pipes on older vehicles.
9. Body and Structure
What is tested:
- Bodywork — sharp or protruding edges that could injure pedestrians are a failure
- Structural integrity — serious corrosion near suspension or steering mounting points is a dangerous failure
- Boot lid and bonnet — must open and close correctly and latch securely
- Doors — must open from inside and outside, and close and latch securely
Common failures: Severe corrosion in structural areas, sharp damaged bodywork edges, doors that do not latch properly.
10. Number Plates
What is tested:
- Both plates must be present, secure, and fully legible
- Correct font and spacing (number plates must conform to DVLA standard)
- Number plate light must illuminate the rear plate
Common failures: Dirty or partially obscured plates, non-standard fonts, missing or loose plates, non-functioning number plate light.
Check yourself: Clean both plates and ensure they are firmly attached. The characters must be readable from 20 metres.
Pre-MOT Checklist — 10 Things to Check Before Your Test
Here is a quick summary of the checks you can do at home in under 15 minutes:
- ✅ All lights working (headlights, brake lights, indicators, fog lights)
- ✅ Tyre tread depth above 1.6mm on all four tyres
- ✅ No tyre sidewall damage or bulges
- ✅ Screenwash reservoir full
- ✅ Wipers clearing the windscreen cleanly
- ✅ No windscreen chips in the driver’s critical zone
- ✅ Horn working and producing a continuous sound
- ✅ Seatbelts latching, retracting, and locking correctly
- ✅ Number plates clean, secure, and legible
- ✅ Handbrake holding the car on a slope
These simple checks take almost no mechanical knowledge and could save you a retest fee.
Book Your MOT Test at ExpressMot
Now you know exactly what the tester is looking for, you can prepare your car and go into your MOT with confidence. When you are ready to book, ExpressMot makes it simple.
- Free MOT check → confirm your MOT status and due date instantly
- MOT test booking → online booking with same-day and next-day availability
- MOT near me → find your nearest DVSA-authorised ExpressMot centre
- Car repair → same-day repairs for MOT failure items
Book your MOT test at expressmot.com and pass with confidence.
ExpressMot — DVSA-authorised MOT testing and car repair across the UK.
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