What does an MOT check?

DVSA’s guide to the car parts checked at an MOT sets out the main areas. Grouped together, they are:

Brakes, steering, suspension and tyres

• The brakes: their condition, how well they perform on the brake efficiency test, and the ABS and electronic stability control, where the car has them. The tester also checks whether the brake fluid has been contaminated.
• The steering and suspension: their condition, whether they work correctly, the steering oil level and the steering lock.
• The tyres and wheels: their condition and security, the size and type of each tyre, and the depth of the tread.

Lights, windscreen and mirrors

• The lights, including HID and LED lamps: their condition, whether they work and where the headlamps aim, plus any headlamp cleaning or self-levelling.
• Reversing lights on cars first used from 1 September 2009, and daytime running lights on cars first used from 1 March 2018.
• The windscreen, for its condition and the driver’s view of the road, and the wipers and washers, which must give a clear view.
• The mirrors: that there are at least as many as the car must have, and their condition and security.

Seatbelts, seats, doors and the body

• Each seatbelt the car must have: that it’s fitted, suitable, in good condition, working and securely attached.
• The seats: the driver’s seat must adjust, every seat must be securely fitted, and the seat backs must fix in the upright position.
• The doors, which must latch shut. The front doors must open from inside and outside, and the rear doors from outside.
• The bonnet, which must close securely, and the boot or tailgate, which must close properly.
• The body and structure, which must be free from excessive corrosion or damage in certain areas, with no sharp edges likely to cause injury.
• The horn, which must work and suit the car, and any towbar, including its 13-pin electrical socket.

Fuel, exhaust and emissions

• The fuel system, for leaks and the condition of its pipes and hoses, and the fuel cap, which must fasten and seal securely.
• The exhaust, which must be secure and complete, without serious leaks and not too noisy, with its catalyst in place if one was fitted as standard.
• The exhaust emissions, against the rules for the car’s age and fuel type, and any fluid leaks that put the environment at risk.

Identification and electrics

• The registration plates: their condition, fixing and colour, and whether the characters are correctly formed and spaced.
• The vehicle identification number (VIN), which cars first used from 1 August 1980 must display.
• The speedometer, which must work, and the engine mountings, which must be secure.
• The battery and any electrical wiring the tester can see.

The MOT inspection manual sets out everything that’s tested, how the tester checks it and the reasons things can fail. Its introduction explains the dangerous, major and minor categories.

An MOT isn’t the same as a service, and it doesn’t check the car’s general mechanical condition. In particular:

• the condition of the engine, clutch and gearbox isn’t covered
• spare wheels and tyres aren’t inspected
• the wheels and trims stay on for the brake test

Your handbook says when the car needs a service. If something feels or sounds wrong, a diagnostic job asks a garage to find the cause. What a pass or a fail means is in MOT results explained.

The tester checks a number of dashboard warning lights, including those for the airbags, seatbelt pretensioners, ABS, electronic parking brake and electronic power steering, and the tyre pressure monitoring system on cars first used from 1 January 2012. Some lights showing a fault are major defects, which fail the test: the MOT inspection manual includes the ABS light showing a malfunction, and the engine warning light on petrol cars first used from 1 July 2003 and diesel cars first used from 1 July 2008. Our guide to dashboard warning lights has the detail.

GOV.UK and the Highway Code list checks any driver can make, and several cover parts the tester looks at:

• Tyre tread. A car’s tyres need at least 1.6 mm of tread across the middle three-quarters of the tread, all the way round. The MOT inspection manual counts tread below that as a dangerous defect.
• Tyre condition and pressures. Look for cuts and other damage, and keep the pressures at the car maker’s figures for the load you’re carrying. An obviously under-inflated tyre is a minor defect at the MOT.
• Lights and number plates. Check every light works, and wipe the lights, reflectors and number plates: the Highway Code requires them to be clean and clear.
• Glass and washers. Clean the windscreen, windows and mirrors, and top up the washer bottles if they need it.
• Under the bonnet. Your handbook says how often to check the engine oil, the water level in the radiator or expansion tank, the brake fluid level and the battery.
• Diesel cars. DVSA advises taking the car to its MOT with the engine fully warmed up, because it makes less smoke and is safer to test.

If you’d rather a garage looked the car over first, ‘Pre-MOT check’ is a job you can post on Matchanic, and garages on Matchanic can see it and choose whether to quote.

An MOT can only be done at an approved MOT test centre, which you can recognise by the blue sign with 3 white triangles. Matchanic doesn’t check whether a garage is an approved test centre, so if you post an ‘MOT test’ job, ask the garage before you accept its quote.

There’s a maximum fee a test centre can charge, and it depends on the type of vehicle. For a car with up to 8 passenger seats it’s £54.85, and you don’t pay VAT on the MOT fee. GOV.UK’s MOT fees table lists the rest.

On the day, you can watch the test from a viewing area, but you’re not allowed to interrupt the tester. If you can’t take the car in yourself, someone else who’s insured to drive it can, and some test centres will collect the car and bring it back.