MOT visibility guide

Can A Windscreen Chip Fail MOT?

A windscreen chip or crack can fail an MOT in the UK if it affects the driver’s view of the road. Zone A damage is judged more strictly, and even smaller chips can become serious if they spread across the screen.

Can a windscreen chip fail MOT UK guide
Quick answer

Will a windscreen chip fail an MOT?

A windscreen chip can fail an MOT if the damage is more than 10mm in Zone A, or more than 40mm elsewhere in the windscreen’s swept area, where it significantly affects the driver’s view of the road.

A small chip outside the driver’s main viewing area may still pass, but it can worsen later. Repairing chips early is usually cheaper and safer than waiting until the screen cracks.

Tester view

What the MOT tester is checking

The tester is checking whether the driver has a clear view through the windscreen. That means the chip size, position, distortion, repair quality, wiper-swept area and anything else blocking vision all matter.

A chip is not judged only by how annoying it looks. It is judged by whether it affects the driver’s ability to see the road clearly.

Failure points

When a windscreen chip can fail an MOT

The MOT visibility check is about whether the driver has a clear view of the road.

Zone A

Damage over 10mm

Damage over 10mm in Zone A can fail because this is the driver’s main viewing area.

Swept area

Damage over 40mm

Damage over 40mm elsewhere in the wiper-swept area can fail if it affects the driver’s view.

Crack

Spreading cracks

Cracks are more likely to become a problem because they can run across the screen.

Multiple chips

Several smaller marks may still affect visibility when grouped together.

Poor repairs

A repair can still be an issue if it leaves distortion, cloudiness or marks in the driver’s view.

Other obstructions

Wipers, washers, tinting, stickers, mounts and decorations can also affect the MOT result.

Zone A

What is Zone A?

Zone A is the main area directly in front of the driver. It sits within the wiper-swept area, is 290mm wide, and is centred on the steering wheel.

Damage here is treated more seriously because it can directly interfere with the driver’s forward view.

Simple explanation

Why Zone A matters

Think of Zone A as the part of the windscreen you rely on most when judging traffic, pedestrians, road markings and hazards ahead. Even a small chip can be distracting if it sits right in that line of sight.

That is why the allowed damage size is smaller in this area.

Screen areas

Windscreen areas explained

The same chip can be judged differently depending on where it sits.

Zone A

Main driver viewing area. Damage over 10mm can be an MOT issue.

Wiper-swept area

The part cleared by the wipers. Damage over 40mm can be an issue.

Outside swept area

Still worth repairing, but it is judged differently from the main viewing area.

Damage type

Windscreen chips vs cracks

Chips and cracks behave differently, especially with weather, vibration and potholes.

Chip

Small chip

A small chip may pass if it is outside Zone A, not spreading and does not significantly affect the driver’s view.

Star break

Star-shaped chip

A star-shaped chip can spread into cracks, especially with cold weather, potholes and vibration.

Crack

Long crack

A crack is more concerning than a small chip because it can spread and may obstruct vision across the swept area.

Edge

Edge crack

Damage that reaches or starts near the edge of the screen can be harder to repair and may require replacement.

Repair advice

Should you repair a windscreen chip before MOT?

Usually yes. Small chips can often be repaired quickly if dealt with early. Once cracks spread, replacement is more likely.

A good repair should be flush or barely noticeable and should not distort the driver’s view.

Replace?

When replacement may be needed

Long cracks, multiple chips, edge damage or damage in critical viewing areas may need a new screen rather than a simple repair.

If the car has cameras or driver-assistance systems attached to the screen, calibration may also be needed after replacement.

Repair decision

Repair or replace?

The right answer depends on the size, position, type of damage and repair quality.

Repair

Repair may be enough

Small chips that have not spread are often suitable for resin repair.

Replace

Replacement may be needed

Long cracks, multiple chips, edge damage or damage in critical areas may need a new screen.

Soon

Do not delay

Temperature changes, potholes and body flex can turn a chip into a crack.

Cover

Insurance may help

Many UK policies include windscreen repair or reduced-cost replacement cover.

Pre-MOT checks

What to check before your MOT

These checks help catch windscreen and visibility problems before test day.

1

Check the driver’s line of sight

Look for chips, cracks, star breaks or scratches directly in front of the driver.

2

Check the wiper-swept area

See whether the damage sits inside the area cleared by the wipers.

3

Check Zone A

Look carefully at the area centred on the steering wheel.

4

Watch spreading cracks

If a crack has grown since it first appeared, repair or replacement is more urgent.

5

Check wipers and washers

Make sure the wipers clear properly and the washers spray enough fluid.

6

Remove obstructions

Remove stickers, sat-nav mounts, air fresheners or objects blocking the driver’s view.

Visibility

Other visibility issues that can fail an MOT

A windscreen chip is only one visibility issue. The driver must be able to see clearly.

Objects blocking view

Mounts, stickers, dash items or decorations can fail if they obstruct the driver’s view.

Severe tinting

Heavy tinting or discolouration can affect forward visibility.

Heavy scratches

Scratches, smearing or screen damage can become a problem if the driver’s view is affected.

Repair costs

Typical UK windscreen repair costs

Costs vary by vehicle, insurance cover, glass type and whether cameras or sensors are fitted.

Chip repair

Usually the cheapest option if caught early and the damage is suitable for repair.

Standard windscreen

More expensive than a chip repair, with cost depending on the vehicle and glass type.

ADAS / camera screen

Can cost more because cameras or driver-assistance systems may need calibration.

Used car check

Windscreen chips when buying a used car

A chip or crack should not be ignored when viewing a used car. It may be a small negotiation point, or it may mean the screen needs repair before the next MOT.

Check whether the damage is in Zone A, whether it has been repaired properly and whether old MOT history mentions visibility advisories.

Real-world faults

Windscreen problems drivers often miss

These are common issues noticed during MOT preparation and used car checks.

Small chip directly ahead

A small chip can matter more if it sits in the driver’s main view.

Chip turns into crack

Cold weather, heater use, potholes and vibration can make damage spread.

Poor repair haze

A repair can still be distracting if it leaves haze or distortion in Zone A.

Wipers smear across chip

Bad wipers can make marks, cracks and dirt more distracting in rain.

Phone mount in view

A mount placed badly can become an obstruction even if the screen is undamaged.

ADAS camera screen

Some windscreens cost more to replace because camera calibration may be needed.

Best advice

Best pre-MOT advice

If the chip is in front of the driver, repair it before the MOT rather than hoping it passes. Even if it is small now, a spreading crack can quickly become a failure or require a full windscreen replacement.

For a full pre-test checklist, read how to prepare for an MOT test.

Do not forget

Visibility is more than glass

A clean, undamaged windscreen still needs working wipers and washers. The tester needs to see that the driver can maintain a clear view in normal use.

Check the simple items before test day because they are avoidable failures.

FAQs

Windscreen chip MOT questions

Common questions about Zone A, cracks, repairs, wipers and driver visibility.

Can a small windscreen chip fail MOT?

Yes, if it is in the driver’s main viewing area and large enough to significantly affect visibility.

What size chip fails MOT?

Damage over 10mm in Zone A or over 40mm elsewhere in the swept area can be an MOT issue if it significantly affects the driver’s view.

Can a repaired chip pass MOT?

Yes, if the repair is flush, barely noticeable and does not distort or interfere with the driver’s view.

Can a cracked windscreen fail MOT?

Yes. Cracks that obstruct vision, spread through the swept area or exceed the relevant limits can fail.

Should I repair a chip before MOT?

Usually yes, especially if it is in front of the driver, spreading or likely to get worse.

Can cold weather make cracks worse?

Yes. Temperature changes can cause chips to spread into larger cracks.

Can wipers or washers fail the MOT too?

Yes. Wipers and washers can fail if they do not give the driver a clear view through the windscreen.

Can a sat-nav mount or sticker fail an MOT?

Yes, if it significantly obstructs the driver’s view of the road.

Motor Vehicle Expert publishes practical UK-focused vehicle diagnostics, maintenance, MOT, warning light, used car and repair cost guidance based on common driver questions and real-world garage situations.