How do I prepare my car for its MOT?
Make sure the lights, tyres, brakes, wipers and mirrors are in order, have the fuel cap key to hand and, for a diesel, arrive with a warm engine. The MOT does not cover the engine, clutch or gearbox.
Last reviewed . The official sources it draws on, and the date each was read, are listed at the foot of the page.
What GOV.UK says to check yourself
GOV.UK says that every time you drive you should check that the windscreen, windows and mirrors are clean, all lights work and the brakes work. Your handbook will tell you how often to check the engine oil, the water level, the brake fluid level, the battery, the washer bottles and the tyres, and when the car needs a service.
What the test looks at that you can see
- Lights: their condition and operation, headlamp aim and the main beam warning light.
- Wipers and washers, which must work properly so the driver has a clear view, and the condition of the windscreen and the driver’s view of the road.
- The horn, which must work properly and be suitable for the vehicle.
- Registration plates: condition, secure attachment, colour and correctly formed and spaced characters.
- Mirrors, seatbelts and seats, and that the doors, bonnet and boot close securely.
- The fuel cap, which must fasten and seal securely: GOV.UK says to make sure the key is available, because the cap will need to be opened.
Tyres
The test checks tyre condition, security, size and type, and tread depth. GOV.UK gives the legal tread depth for cars, light vans and light trailers as 1.6 millimetres, across the middle three-quarters of the tyre and around its entire circumference. Vehicles first used on or after 1 January 2012 are also checked to make sure the tyre pressure monitoring system warning light is working.
Dashboard warning lights
The test checks the warning lights for airbags, seatbelt pretensioners and load limiters, the anti-lock braking system, electronic stability control, the electronic park brake, brake fluid, electronic power steering and the steering lock. A lit warning for any of these is worth investigating before the test.
Diesel cars
GOV.UK says the tester will refuse to test a vehicle if they think the smoke test may damage the engine, and that you should tell them at the start if you think this may happen. To reduce the chance of damage and improve your chances of passing, keep the car maintained, have the camshaft drive belt replaced at the recommended intervals, go to the test with a fully warmed up engine and do not tamper with the governor settings.
What the MOT does not cover, and Northern Ireland
The MOT is not the same as a service and does not cover the condition of the engine, clutch or gearbox. This guidance is for tests in Great Britain; in Northern Ireland the Driver and Vehicle Agency runs the test, and nidirect explains how to book it.
Sources
- GOV.UK: Car parts checked at an MOTRead on 6 October 2026. The items the test checks, the fuel cap key, the warning lights tested, the tyre pressure warning for vehicles first used from 1 January 2012, advice for diesel cars, and what is not covered.
- GOV.UK: Check your vehicle is safe to driveRead on 6 October 2026. The checks to make every time you drive, the handbook checks and the legal tyre tread depth of 1.6 millimetres for cars.
- nidirect: A guide to booking your MOT/ vehicle testRead on 6 October 2026. In Northern Ireland the Driver and Vehicle Agency runs the test; booking online or by telephone.
Related
More answers
- What MOT class is my car?
- How long does an MOT last, and how often do I need one?
- How do I find out when my MOT is due?
- Do electric cars need an MOT?
- Can I drive a car with no MOT?
- Do I get a car tax refund when I sell my car?
- How do I check if a car has outstanding finance?
- How do I tell DVLA I have sold my car?
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