How a Windscreen Crack Can Lead to MOT Failure

A cracked windscreen might seem like a minor inconvenience – but when it comes to your MOT, it could be the reason your vehicle fails the test.

Many scenarios of a cracked windscreen may lead to your view of the road being compromised, therefore putting the safety of both you and others at risk.

This guide explains how a windscreen crack can affect your MOT result, the rules surrounding visibility and driver safety, and what steps to take if your screen is damaged.

We’ll also cover the common causes of windscreen damage and how to avoid MOT trouble in the future.
 

What Causes Windscreen Cracks?

While not always avoidable, there are some common reasons a windscreen might become chipped or cracked:

• Stone chips from the road: Especially common on motorways or behind construction vehicles.
• Sudden temperature changes: Pouring hot water onto a frozen windscreen can cause it to crack due to thermal shock.
• Old or damaged wiper blades: These can drag grit across the glass, scratching or weakening it.
• Poor road surfaces: Driving on gravel or pothole-ridden roads can increase the risk of flying debris.

Spotting damage early and getting it repaired quickly is key to avoiding a worsening crack and an MOT failure.
 

Why Does a Cracked Windscreen Fail an MOT?

When your car undergoes its MOT, one of the main safety concerns is the driver’s visibility.

Any obstruction – especially in the area directly in front of the steering wheel – can compromise your ability to see the road clearly.

This of course can lead to accidents on the road, putting drivers, passengers, and pedestrians at risk.

As a result, windscreen damage is taken very seriously during the inspection.

The MOT Rules on Windscreen Damage

The MOT tester will examine the windscreen for chips or cracks and measure their size and location.
The rules are based on two specific zones:

• Zone A: This is the 290mm-wide area directly in front of the driver’s seat, centred on the steering wheel. Any crack or chip larger than 10mm in this area will result in an automatic MOT failure.
• Zone B: The rest of the windscreen. Here, damage greater than 40mm will also lead to a failure.

Even if the damage doesn’t immediately exceed these limits, testers may still mark it as a small defect/advisory, meaning it’s not a fail yet but could worsen over time and should be repaired.
 

What Else Will Be Checked During the Windscreen Inspection?

Windscreen integrity isn’t the only visibility factor assessed during your MOT.

The condition and performance of your windscreen wipers will also be checked. If the wiper blades are torn, loose, or unable to clear the screen effectively, your car will fail the test. MOT testers look for any signs of damage or poor operation that could compromise the driver’s view in wet conditions.

The washer system is equally important. Your vehicle must have enough washer fluid to clean the windscreen when needed. Blocked jets, broken pumps, or an empty reservoir can all lead to an MOT failure.

Thankfully, these are some of the easiest issues to fix, so it’s worth checking both your wipers and washer fluid before heading to your appointment.
 

Can I Drive to an MOT Test with a Cracked Windscreen?

If your vehicle is already booked in for an MOT or repair, you can legally drive it to the garage – as long as it’s roadworthy and safe to drive.

However, if the crack obstructs your vision or is likely to worsen while driving, it’s best not to take the risk.
In that case, arrange for a mobile repair service or have the car towed to a local garage.

How to Prevent Windscreen Damage (and Avoid MOT Trouble)

While not all cracks are preventable, you can reduce the risk with some proactive steps:

• Keep your distance on the road to avoid stone chips.
• Avoid sudden heat on a frozen windscreen – use a proper scraper and warm air from the heater instead.
• Replace your wiper blades once a year to prevent scratching.
• Top up washer fluid regularly and clear blocked nozzles.
• Check for damage regularly – especially after long drives or poor weather.

A little preventative care can go a long way toward avoiding MOT failure and maintaining road safety.
 

Final Takeaways

A cracked windscreen might start as a small nuisance – but left untreated, it could cost you an MOT pass, a fine, or even penalties to your driving licence.

If you’ve spotted any damage ahead of your MOT, don’t delay. Get it checked by a qualified technician and take care of any repairs early.

It’s important to note that it’s possible to fix small cracks by filling them with resin repair kits. Some insurers cover this at no cost.

However, larger windscreen cracks may not be fixable and will require a full windscreen repair. In this case, please contact your local garage – this is typically covered through most comprehensive insurance policies and may not affect your no claims bonus.

Always speak to your insurer before proceeding to understand any impact on your policy.

This way you can keep your car compliant for its upcoming MOT test, as well as keeping yourself and others safe on the road.