How to prepare your Car for its annual MOT Check

February 18, 2023 by Zoe Hicks – 5 mins read

Crossing your fingers and leaving it to fate on MOT test day isn’t how you pass. And with silly resolvable issues accounting for most test fails, it makes sense to do something about it. So, follow Motorscan’s top tips guide on preparing your car for its MOT to give your vehicle the best possible chance of breezing through!

Every year, without thinking, we dutifully drive our vehicle down to the MOT centre and, with fingers and toes crossed, hope the tester finds nothing wrong. But with just 30% of MOT tests passing the first time and many failing on fundamentally resolvable issues, Motorscan has prepared a super helpful guide on preparing your car for its yearly MOT test and giving it the best chance of passing with flying colours. Of course, there will be unforeseen issues that you can’t check and resolve yourself. But, following our top tips and resolving the DIY-serviceable items before the test day, you’ll know you’ve done everything possible to get that all-important MOT pass!

Clean your Car

It may sound elementary, and no, a dirty car won’t fail an MOT, but you can fail an MOT if dirt or droppings obscure driver visibility, lights or number plates. So, clean your vehicle inside and out, ensuring you don’t make it easy for the tester to fail your car. Pay particular attention to ensuring that headlights, brake, and rear lights are free of dirt and clean the windows, particularly the windscreen and front side windows, to avoid visibility-related fails.

Check your Number Plates

Not complying with current number plate regulations will result in an MOT failure, so check that your number plates comply, are not obscured by any dirt or marks, and aren’t peeling or discoloured. And to ensure your plates are fully compliant, purchase number plates from a licenced number plate supplier.

Inspect your Tyres

The legal tyre tread depth in the UK is 1.6mm across the tyre’s central three-quarters. So if you measure 3mm on one part, but it’s 1.6mm elsewhere, you need to change your tyre. And don’t worry if you don’t have a tyre tread gauge. You can still use the tyre tread indicators on the tyres or a 20p coin by inserting it into the tyre tread grooves. Using the outer band on the 20p as a measurer, if this band disappears into the tyre grooves and isn’t visible, your tyres are legal. However, if you can see any part of the coin’s outer band, your tyres are below the legal limit and unsafe. Also, ensure you have a good look all the way around and check for any bulging or damage to the tyre wall which will also cause an MOT to fail.

We also recommend checking that your tyres are inflated correctly per the manufacturer’s recommendations in your vehicle’s handbook. Whilst tyre pressures aren’t part of the MOT, if any tyres are visibly under-inflated, the MOT tester could fail the car; checking tyre pressures is worth it to avoid any unnecessary disappointment.

Check all the Fluids

Whilst having a low brake fluid level isn’t an MOT fail anymore, you can still fail if your screenwash is empty or fuel and oil levels are too low for the tester to perform the emissions test. So make it a regular item to check all your fluid levels, especially before MOT day, particularly oil and screenwash. And, even if they don’t affect your MOT, maintaining your vehicle with correct fluid levels will keep it in better condition for longer and keep you and your passengers safe.

Check your Wiper Blades

Visibility is essential for safety, so it’s no surprise that the MOT includes this as part of the test. Accordingly, you should ensure your wipers operate correctly, sweeping and clearing the windscreen effectively, and if you have worn wipers or you get smearing when they wipe, replace them. You should also check to ensure that the water from the screenwash effectively sprays your windscreen to clear dirt or droppings if needed.

Inspect the Windscreen

Take time to look over the windscreen. You should ensure there aren’t any cracks or chips measuring more than 10mm in the line of sight of the driver, which is the 29cm wide section centred on the steering wheel. Elsewhere in the wiping section of the windshield, you’re allowed no larger than 40mm chips or cracks.

Test your Horn

Quite rightly, the MOT deems it vital that you have a working horn to alert other road users of imminent danger, so test your horn before MOT day and make sure it conforms. For example, the sound should be continuous and loud enough for other road users to hear but not deafening or annoying, and you’re not allowed non-compliant sounds such as two-tone noises, bells or sirens.

Enrol a friend to help test your Lights

Non-functioning lights are one of the most common reasons for MOT failures but the easiest to check and resolve before test day. So with the help of a family member or friend, check all the car lights for blown bulbs and replace them if necessary. Ensure you check both the main and dipped beam along with the rear, brake, fog and indicator lights. And don’t forget the bulbs that light up your number plates, as these are relevant and can fail an MOT too.

Check that the Mirrors conform

Under the MOT, your car needs to have a minimum of two mirrors providing offside and rear views. It means you will need one inside rearview mirror and at least a wing mirror on the driver’s side, providing an offside view. However, having a working nearside mirror is also essential to see all hazards. Whilst a missing or broken nearside mirror won’t fail an MOT, it may still cause a stop by the Police. Otherwise, your mirrors should be intact with no distortion and free of any dirt that may otherwise obscure visibility. So, ensure your mirrors are clean to avoid a silly fail!

Inspect Seatbelts and Seats

It’s also good practice to check over your seatbelts and seats to ensure they operate correctly and are undamaged. For instance, ensure that all required seat belts are present and functioning, including the belt mechanism locks and releases correctly, and the belt itself is undamaged and has no rips or cuts. In addition, seats should be secure, adjustable and able to be fixed in the upright position.


A guide to the MOT Test
A guide to the MOT Test
If you own and use a vehicle on the road it is your responsibility to ensure this vehicle is maintained and kept in a condition that deems it roadworthy at all times.