MOT test explained

Cars over three years old must by law pass a yearly MOT test to show that they are roadworthy. Find out more about the MOT, including the five most common simple reasons why cars fail it. There’s also a checklist to help you give your car the best chance of a pass, and so avoid the cost and hassle of a re-test.

Key facts about the MOT test

Did you know?

You can also get an MOT done at a local council test centre.

These test centres don’t normally carry out repairs as well as MOTs. This makes them impartial when inspecting your car – here’s no commercial incentive to find problems with it.

For a list of local council MOT test centres that don’t carry our repairs, visit the UKMOT website.

Once a car is three years old (four years in Northern Ireland) it must be tested each year to check that it meets road safety and environmental standards. This Ministry of Transport test is commonly known as an ‘MOT’.

MOT tests are carried out at around 21,000 authorised test centres around the country, all of which display an official blue sign featuring three white triangles.

An MOT involves dozens of checks on your car, ranging from the brakes and fuel system to lights, mirrors, seatbelts, windscreen wipers and exhaust system. It doesn’t cover the condition of the engine, clutch and gearbox.

To find your nearest authorised MOT test centre, visit these websites:

Top 5 simple reasons for cars failing the MOT test

Top Tip

The Vehicle and Operator Services Agency sets the maximum fee that official test centres can charge for an MOT. It’s currently £54.85, but many garages charge less than this – sometimes up to 50% less.

According to What Car? Magazine, the average MOT test price is £45.

Search online for “cheap MOT” or “MOT discount” to find out how you can save money on your car’s next MOT.

Nearly two in five MOT tests are a fail first time. Yet often this is because of minor faults that the owner could easily have fixed beforehand.

Here are the top five simple reasons for an MOT fail, according to research published by What Car? Magazine in April 2014:

  1. Screen wash not topped up. This basic task takes minutes, so don’t be caught out by it.
  2. The car was dirty or full of clutter. Clear the mess from the boot and cabin and give the windows and mirrors a quick wipe.
  3. A registration plate problem. For example, the plate showed the incorrect type face/spacing, or was dirty or missing altogether. If you have a personalised plate, make sure it follows DVLA rules.
  4. Stickers on the windscreen blocking the driver’s view. Make sure that anything stuck to the windscreen, including tax disc and parking permits, is outside the wipers’ sweep area.
  5. Lit-up warning light on the dashboard. The MOT has included lit-up warning lights since 2012. So make sure you know what lit-up up car warning lights mean and if you have any sort out the underlying problem before the MOT.

Checklist to help your car pass its MOT


An MOT certificate confirms that at the time of the test your car met the minimum road safety and environmental standards required by law.

It doesn’t mean that your car will remain roadworthy for the following 12 months. You still need to make sure that you maintain your car well, including regular servicing.

Make sure you’re not caught out by any of the five simple reasons for a fail shown above, then inspect your car against our 11-point checklist below.

If you find any problems in the following areas, there are some you can fix yourself to help keep garage costs down.

Headlights and indicators: front, rear, headlights (main beam and dipped), hazard lights and indicators. If any aren’t working, first check for broken bulbs and replace them.

Brake lights: ask another person to check that the rear brake lights come on when you press the brake pedal.

Tyres: check that all the tyres have at least the minimum legal tread depth of 1.6mm, or they will be marked as an MOT ‘fail’. This can easily be done with a 20p coin – watch the video on the First Time Driver website.

Check for any damage such as splits in the tread, bulges or cuts in the sidewalls. Also check the tyre pressure and increase it at a petrol station if necessary.

The handbrake: check the tension in your handbrake. If it slides up and down without resistance and can’t be ratcheted to a set level, there’s likely to be a problem that needs fixing by a professional mechanic.

Seats and seatbelts: check that the driver’s seat adjusts forwards and backwards and inspect the full length of the seatbelt for any damage. Check that all of the seatbelts latch and fasten securely, and lock when you give them a sharp tug.

Windscreen: any damage wider than 10mm in the driver’s central view will cause an MOT fail, as will any damage larger than 40mm in the whole of the swept area.

Windscreen wipers: make sure that your wipers clean your windscreen effectively in conjunction with the washers. Remember that any tears or holes in the wiper rubber can mean an MOT fail.

Suspension check: check the shock absorbers by applying your weight to each corner of the car then quickly releasing it. The corner of the car should quickly return to its original position. If it bounces more than twice, this could mean that the shock absorbers are faulty and need to be checked.

Horn: give a short blast of the horn – if it doesn’t work or isn’t loud enough to attract the attention of pedestrians or other motorists, get it repaired.

Exhaust: check for exhaust leaks by starting the engine in a well-ventilated space at normal temperature, then listen from the rear of the car for any unusual noises or abnormal smoke.

Fuel and engine oil: make sure your car is filled with enough fuel and engine oil – you can be turned away from the MOT if there isn’t enough to test your car’s emissions levels properly.

If your car fails its MOT

If your car fails its MOT, the test centre will give you a VT3O Certificate showing the reasons for the fail. You need to fix these failure points and arrange a partial MOT retest in which your car must pass on them before you can drive it on the roads again.

You may be able to get a partial MOT retest for free or for a reduced fee. This depends on whether you leave your car at the test centre for repairs or have the work done elsewhere and bring it back for testing within a time limit (normally 10 days).

If your MOT has expired

Top Tip

To find out more about the MOT test or to register to receive MOT reminders by text, go to the GOV.UK website.

If your MOT has expired, it’s illegal to drive your car on the road and you could be prosecuted for doing so. Driving without a current MOT also makes your car insurance invalid.

The only exception would be if you already had an MOT booked and were driving your car to the test.