The MOT. The mere mention of the test can strike fear into the hearts of busy motorists. The MOT was introduced in 1960 by Ernest Marples after the Road Traffic Act of 1956 was ratified. Originally, the test was basic: brakes, lights and steering were checked. This simple version was called the “ten year test,” but when scores of motorists failed it, the Ministry of Transport made it a “seven year” test instead. In 1983, the ministry reduced the test interval for taxis and ambulances to one year. Sure enough, the MOT is now a yearly exam for most everyone. Here is a breakdown of how it works:

  • Do the MOT inspection three years after registering your vehicle
  • Get it done every year after that

See our handy FAQ for more general information about the MOT. In this post, we’ll let you know which systems are tested.

Lamps, Electrical Systems and Reflectors


The following lights will be checked:

  • Front
  • Rear
  • Brake
  • Fog
  • Registration plate lights

Check your lights to make sure they are positioned correctly and are secure. Make sure your lights are not obscured by wires, debris or other materials. The MOT also requires that lights are in “good condition.” If in doubt, replace them.

Front headlines can have a bluish tint, but the predominant colour must be white. Pairs of lights, such as the front and taillights, must be of the same colour and shape.

19% of MOT failures are due to faulty or poorly maintained lights. Before your test, ask someone to walk around your vehicle and check them.

The Battery

The battery must be secure in its bed. Additionally, the battery should be in good condition—free of corrosion and electrolyte.

The Horn

Your horn must emit a continuous note when pressed, and it must be loud enough to be heard by other motorists.

The Wiring

Wiring must be secure and in good shape. If your wires are split or scraped, replace them. Your inspector may cite the damaged wires as a possible fire hazard if they look like they could short-circuit or become detached.

The Steering and Suspension System

Shock Absorbers

Shock absorbers should be in good condition and free of excessive corrosion and fractures.

Tyres and Wheels

The legal limit for tread depth is 1.6mm. Additionally, your inspector will check your tyres for physical defects and excessive wear. They will check for:

  • Bulges
  • Cuts
  • Lumps,/li>
  • Cord and tread separation

If you have run-flat tyres, your inspector check the corresponding warning light.

8% of MOT failures come down to the tyres! Make sure your tyres are rated for your vehicle and that they’re properly inflated.


The MOT tests the brakes for efficiency. In addition, the inspector will manually inspect the condition of breaks, levers and pedals.


Your inspector will examine your steering column and steering wheel for signs of corrosion and wear. He or she will manually test the steering column by turning the wheel left and right. Your steering wheel’s locking device will also be tested as will your power steering system. Ensure that your power steering system has plenty of power steering fluid.

Structure, Restraint Systems and Misc. Items

Seat Belts

Your inspector will check each seat belt individually. Belts must not be cut or frayed.

The Vehicle Body

Your inspector will look at the engine mountings, chassis, seats and doors of your vehicle. He or she will also do a general inspection of the body itself. Your vehicle body must be free of excessive corrosion. Make sure that your car body has no sharp edges that could cause injury to someone else.

Registration Plates

You must have a registration plate at the front of the vehicle and at the rear. Naturally, these plates must be secure and clearly legible. Your inspector will check to see if they can read the plates from 20 metres away. Ensure that there isn’t any dust or debris obscuring these tags.


Your vehicle identification number must be clearly legible. Your VIN can appear on a VIN plate or the dash. Consult your vehicle’s documentation if you’re not sure.


If you have an analog speedometer, it must have a dash light. Your inspector will check for this. If you have a crack in the dial, don’t panic. As long as the inspector can read the speed, you’re alright. If you have a digital speedometer, the inspector will ensure it works by popping the car into drive and moving forward a few feet.


The Exhaust System

Your inspector will check to make sure your exhaust system is not leaking.

Note: if your vehicle was manufactured with a catalytic converter, it must be present and in good working order.

To check emissions, your tester will insert a gas analyser probe into your exhaust system. Levels of carbon monoxide and hydrocarbons will be checked. Both must fall within established parameters. Your inspector will also check for “off” looking emissions. If your vehicle’s emissions are blue or black, you will fail the MOT.

The Fuel System

Similarly, the inspector will check your fuel system for leaks. Your tank cap must fit securely.

The Windscreen, Mirrors and Wipers

Mirrors and Wipers

Your inspector will check that your rear view and wing mirrors are secure. Your tester will check that your wipers sweep across the windscreen without obstruction.

The Windscreen

If the area of the windscreen directly in front of the driver has physical defects in excess of 10mm, you will fail the MOT. Similarly, if any area of the windscreen has a physical defect greater than 40mm in size, you will fail.

How We Can Help

Keeping up with all of this is challenge enough! Our free app, YesMechanic, helps car, van, lorry and motorbike owners monitor their MOT, vehicle tax and insurance due dates. Get reminders for these crucial dates from one source directly on your Android phone.

To learn more about YesMechanic, the MOT and other UK road requirements, stay tuned!