What does the MOT test comprise?

MOT Advice
What does the MOT test comprise?

If you’re worried about whether your vehicle will pass its MOT you view our MOT checklist to make sure you are as prepared as you can be to avoid failing on something simple that could easily be addressed in advance.

To give you the best chance of passing your MOT first time, its good know what is included in the MOT test itself:

Lamps, reflectors and electrical equipment:

MOT testers will check all your lights including front, rear, side, brake, fog, indicators, hazards and registration plate.

They will check if they are correctly positioned, secure and emitting the correct amount of light. They will also check the general condition including the colour, and that they are not affected by the operation of another light. They should be able to be illuminated with the operation of a single switch, and pairs of lights should emit the same colour and be the same size and shape.

Find out how to avoid failing your MOT on lights.


The horn must be able to sound a note loud enough to be heard by motorists, pedestrians, cyclists and other road users. It should not cut out or crackle if held continuously.


The MOT tester will check the battery is secure and is not leaking electrolyte.

Electrical wiring:

Wherever there is any electrical wiring it must be secure and show no signs of damage or detachment.

Vehicles with a tow-bar:

If your vehicle has a towbar the electrical socket will be tested to make sure it correctly functions the lights on the trailer.

Steering and suspension:

If you have power steering there must be the minimum amount of power steering fluid in the reservoir. If there is a locking function on your steering, it will be tested to ensure it only locks when the engine isn’t running. The general condition of your steering will be tested including the strength. The tester will turn the steering from left to right to check this.


Shock absorbers and other components will be looked at to make sure they are in good working order and show no signs of corrosion, distortion or fractures.

Find out how to avoid failing your MOT on suspension.


To test how efficient your brakes are the MOT tester will do a brake performance test, whereby the vehicle will be put on a set of revolving rollers. As well as this test, the overall condition of the brakes, pedals and levers are inspected, and any relating warning lights will be checked out.

Find out how to avoid failing your MOT on brakes.

Tyres and wheels:

Wheels will be checked to ensure they are in good overall condition. The MOT technician will check that the tread depth is at least the legal limit of 1.6mm and an examination will be carried out to check for cuts and bulges and lumps. Tyres will also be tested to ensure they are inflated correctly.
If your vehicle is fitted with run-flat tyres the warning light must operate correctly.

Find out how to avoid failing your MOT on tyres.

Seat belts and restraint systems:

Each seat belt (including the attachment and adjustment fittings) will be checked for its security and condition. The must be all in fully working order.

Body, structure and general items:

The MOT test will feature a full inspection of the chassis, body, seats, doors and engine mounting to ensure that they are free from excessive rust and corrosion. The body must not contain any sharp parts which may cause injury.

Registration plates:

The MOT tester will check that both front and rear number plates are securely fitted. The characters must be clear and correctly spaced out so they can be correctly read from 20 metres away.

Vehicle Identification Number (VIN):

Every vehicle comes with a VIN number. This will come in the form of a plate secured to the vehicle or it will be etched or stamped on the body or chassis.


The tester will check that a speedometer is fitted and it is properly illuminated when need be. Your vehicle may not fail its MOT if the dial is cracked, your vehicle will only fail if the speed cannot be clearly read.

Exhaust, fuel and emissions:
Exhaust System

If your exhaust system was originally fitted with a catalytic converter it must still be present. The tester will also make sure there are no leaks and the exhaust system is secure.

Fuel System

The fuel tank cap will be checked to ensure it seals properly and there are no leaks in the fuel system.


A gas analyser probe will be used while the engine is running to test the smoke which is emitted from the exhaust. The vehicle’s carbon monoxide and hydrocarbon emissions must fall within the legal limit. If there is excessive dense blue or black smoke this will cause the vehicle to fail, it’s MOT.

Drivers view of the road:
Mirrors and wipers

Rear and wing view mirrors must be secure and provide a clear view of to the rear and sides of the vehicle. The MOT test will also ensure that the windscreen wipers sweep an area large enough so the driver is able to see the road.


There must not be any damage larger than 10mm to the windscreen in the area which, is directly in front of the driver. I other areas there must not be any damage larger than 40mm.


It is important to note that the MOT tester is not able to dismantle any parts of your vehicle during the MOT test.