Will a Chipped or Cracked Windscreen Fail Your MOT?

Will a Chipped Windscreen Fail an MOT?

Whether a windscreen chip or crack fails an MOT comes down to two things, how big it is and where it sits. In the driver's direct line of sight, damage larger than 10mm will fail. In the rest of the area swept by the wipers, the limit is more generous at 40mm. Damage outside the swept area is not usually a problem.

The reason for the tighter limit in front of the driver is simple. Damage right in the line of sight is far more distracting and dangerous than the same mark over on the passenger side. That is why a chip you might barely notice can still fail if it is directly ahead of the steering wheel. Our overview on What Is an MOT explains where visibility sits in the full test.

The encouraging part is that a small chip caught early can often be repaired rather than replaced. Acting quickly is worthwhile, since a chip left alone can spread into a crack that then needs a whole new windscreen. Catching it early is cheaper and keeps the car test ready.

The Windscreen Zones and Size Limits

The windscreen is divided into zones for the test, with the strictest rule directly in front of the driver. The table below sets out the limits.

So a mark of the same size can pass or fail depending purely on where it is. A chip directly ahead of the driver is judged far more strictly. Our guide on Tyres and the MOT covers the other common visible checks such as tyres.

Fixing a Chip Before It Spreads

A small chip is often repairable, which is quicker and cheaper than a full windscreen. A repair fills the damage and stops it spreading. It can bring the screen back within the limits for the test. The sooner it is done, the better the chance of a neat repair.

Left too long, a chip can grow into a crack, especially with temperature changes or a knock over a pothole. Once it spreads across the driver's view or gets too large, a repair is no longer possible and the whole screen needs replacing. Fixing early is the way to avoid the bigger job. Our guide on Top Reasons Cars Fail MOT covers the other faults that most often cause a fail.

Wipers and Washers Count Too

The windscreen glass is only part of the visibility check. The test also looks at whether the driver can keep the screen clear, which means the wipers and washers have to work properly. A torn or perished wiper blade that smears rather than clears can fail, as can washers that do not squirt.

These are among the cheapest and easiest things to sort before a test. Replacing a worn wiper blade and topping up the washer fluid takes minutes and costs very little, yet it removes an easy reason to fail. It is well worth a quick check the day before your MOT.

Can You Drive With a Cracked Windscreen?

Beyond the MOT, there is a separate question of whether the car is legal to drive with a damaged windscreen day to day. If the damage is bad enough to block the driver's view, the car can be considered in a dangerous condition, which is an offence in its own right regardless of when the MOT is due. So a large crack is not something to leave until test time.

This is another reason to treat windscreen damage promptly rather than waiting for the next MOT to force the issue. A screen that fails the test is often one that was already affecting your view on the road. Getting a chip repaired early keeps the car both legal and safe between tests. Our guide on What an MOT Checks explains how the wider roadworthiness rules apply.

Keep Your View Clear

This guide is part of our full MOT Guides hub, where the testing, cost and rules articles sit together so you can move to the exact detail you need next. When it is time to book, our team offers full MOT testing and repairs from our centre in Ely. You may also find it useful to read What an MOT Checks, Top Reasons Cars Fail MOT and Tyres and the MOT.

Common Questions