In a summary, while it’s not automatically illegal to drive with a tiny chip or hairline crack in your windscreen, the law does draw the line when that damage begins to impair your vision. Under the Road Traffic Act, you’re responsible for keeping your vehicle safe, and a cracked windscreen can land you with a fine of up to £2,500, three penalty points or even a driving ban if it’s deemed dangerous [1]. The DVSA MOT rules break your windscreen into zones: damage in the central “Zone A” must be no bigger than 10 mm, and elsewhere within the swept area no larger than 40 mm, otherwise it fails its test [2]. Bottom line: if the crack is small, keep an eye on it; if it grows or sits directly in your line of sight, you need to get it fixed—fast.

Why a clear windscreen matters

Think of your windscreen as your window to the world when you’re behind the wheel. Even a small crack can catch the light and scatter it, creating glare or hiding a road hazard until it’s too late. Police officers and roadside enforcement teams will assess whether the damage “significantly affects the driver’s view of the road” and can stop you on the spot [2]. If they decide it’s dangerous, you’ll be committing a ‘dangerous condition’ offence under the Road Traffic Act.

The legal limits on windscreen damage

The rules aren’t meant to scare you—they’re there to keep everyone safe. For MOT purposes and traffic officers alike, windscreens are divided into zones:

Zone A (central swept area): no single chip or crack larger than 10 mm in diameter.

Zone B (remaining swept area): no single chip or crack larger than 40 mm in diameter.

Multiple small chips are allowed only if they don’t combine to obscure your view [2].

Penalties for driving unsafely

If your windscreen damage is judged to be a danger, you could face:

A fine of up to £2,500

Three penalty points, or even

A driving ban in severe cases

These penalties apply whether you’re on the motorway, in town or anywhere in between. Remember, it doesn’t matter if you’ve passed your MOT recently—a windscreen can crack between tests and still land you in hot water [1].

MOT considerations

Even if you’ve booked your car in for an MOT, the tester must still check your windscreen on the day. If the damage exceeds the limits for the zones or is within the swept area and deemed to affect visibility, your car will fail the test, meaning you’ll have to get it repaired before it can be driven away.

What to do if you spot damage

Act quickly. Small chips can often be repaired without replacing the whole screen.

Seek professional advice. A trained technician will tell you whether a repair is enough or if a full replacement is safer.

Get it fixed. Driving with compromised visibility isn’t worth the risk or the potential fine—and it could invalidate your insurance if you’re in an accident.

Ready to get back on the road with confidence? Get a windscreen replacement quote today at https://www.ukwindscreens.uk/quote and enjoy clear views ahead.

References

[1] Check your vehicle is safe to drive, GOV.UK – https://www.gov.uk/check-vehicle-safe
[2] View to the front and windscreen obscuration, GOV.UK – https://www.gov.uk/government/publications/stickers-or-other-items-in-front-and-rear-windscreens/view-to-the-front-and-windscreen-obscuration