What Actually Happens During An MOT Test?
A Step By-Step Guide
If you own a vehicle that is more than three years old, booking an annual MOT test is not only recommended but legally required in the UK.
While many drivers understand the importance of having a valid MOT certificate, fewer know what the test actually involves. It’s common to drop your car off at the garage and simply wait for the result, without knowing what the mechanic is checking or how long the process should take.
This article explains what happens during an MOT test in straightforward terms—what’s inspected, how long it typically takes, and how you can better prepare your car to pass first time.
Understanding The MOT Test
The MOT test—short for Ministry of Transport test—is designed to assess whether your vehicle meets the minimum legal standards for road safety and environmental performance. It does not evaluate the mechanical condition of the vehicle in the same way a service would; rather, it confirms that the car is safe to drive, not excessively polluting, and fit to be on public roads.
Vehicles must undergo their first MOT when they reach three years of age and every year after that. Driving without a valid MOT certificate, unless you’re on your way to a pre-booked test or garage, can lead to fines and invalidate your insurance.
How Long Does The MOT Test Take?
On average, an MOT test takes between 45 minutes and one hour. If your vehicle passes without issue, it can usually be collected the same day. However, if the car fails and requires repairs, you may need to leave it at the garage longer, depending on the severity of the problems and availability of parts.
Some garages offer a while-you-wait service, allowing you to stay on site during the test, while others may suggest dropping the vehicle off and returning later in the day.
What Happens During The Test?
The MOT test is a structured inspection carried out by an authorised examiner using official DVSA (Driver and Vehicle Standards Agency) procedures. The inspection covers a wide range of components across the vehicle, each of which plays a role in either safety, emissions, or legality.
Lighting and signalling equipment are among the first items checked. This includes headlights, brake lights, indicators, and rear lights. All lights must work properly, be correctly positioned, and emit the right colour. The number plate lights and dashboard warning indicators are also part of this inspection.
Next, the examiner will inspect the steering and suspension systems. This involves assessing the physical condition of the steering wheel, steering rack, and suspension components such as springs, shock absorbers, and mounting points. The tester checks for signs of wear, corrosion, or damage that could affect handling or safety.
Brakes undergo a detailed examination, both visually and through performance testing on a rolling road. The tester will look at the condition of brake pads and discs, the effectiveness of the handbrake, and whether braking force is evenly distributed across all wheels. The brake fluid level may also be checked as part of the general inspection.
Tyres and wheels are then assessed. The legal minimum tread depth for tyres in the UK is 1.6mm across the central three-quarters of the tread. Tyres must also be in good condition, with no cuts, bulges, or other damage, and must be suitable for the vehicle in terms of size and type. The wheels themselves are inspected for cracks or other structural defects.
One of the most important aspects of the MOT is the exhaust system and emissions test. The examiner checks that the exhaust is securely mounted and not leaking. They will also use specialist equipment to measure the vehicle’s emissions, ensuring they fall within legal limits. Diesel vehicles are checked for visible smoke and for the presence of a diesel particulate filter (DPF), which must not have been removed or tampered with.
Visibility is another key area. The tester examines the windscreen for damage, particularly in the driver’s line of vision, as well as the functionality of the windscreen wipers and washers. Anything that obstructs the driver’s view—such as stickers or dashboard-mounted devices in the wrong position—may be flagged.
The structural integrity of the vehicle is also assessed. This includes checking for rust or damage in areas that could compromise safety, particularly around suspension mounts, seatbelt anchor points, and load-bearing parts of the chassis. Doors, the bonnet, and the boot must open and close properly, and all seatbelts must be in good condition and function correctly.
Finally, the examiner will confirm that the vehicle’s identification number (VIN) is visible and matches DVLA records. The number plates must be clean, clearly legible, and conform to the legal format. Additional checks include the condition and operation of the horn, the speedometer, and any dashboard warning lights that should or shouldn’t be illuminated depending on the situation.
After The Test
Once the inspection is complete, the garage will issue either a pass certificate (VT20) or a failure notice (VT30). If your car passes, you’re legally allowed to continue driving it until the next MOT is due. However, you may still be given advisory notes, highlighting issues that aren’t serious enough to cause a failure but could become problematic later.
If the vehicle fails, you will need to arrange for the necessary repairs before a valid MOT certificate can be issued. In most cases, if the repairs are carried out at the same garage within 10 working days, you are entitled to a free partial retest.
How Understanding The MOT Process Helps You
Understanding what happens during an MOT test can help you stay informed and proactive about your vehicle’s condition. Although the test is mandatory, it also provides a useful annual benchmark for safety and roadworthiness. By addressing minor issues in advance—like faulty bulbs or worn wipers—you can reduce the likelihood of unexpected failures and ensure your vehicle remains both legal and safe to drive.
