Windscreen, wiper and visibility MOT failures
'Visibility' – the driver's view of the road – is in the top five failure areas. Much of it is fixable for a few pounds before the test.
Checked against the MOT inspection manual and GOV.UK guidance · Updated November 2026
Windscreen damage: the exact limits
The windscreen is divided into zones:
- Zone A – a strip 290mm wide, centred on the centre of the steering wheel, within the area swept by the wipers. Damage larger than 10mm in diameter here fails.
- The rest of the swept area – damage larger than 40mm fails.
Damage is measured as the diameter of a circle that would contain it – so a crack is measured end to end. Most cracks are well over these limits. A chip repair is far cheaper than a new screen, but only possible on smaller damage, and in zone A the repair itself can't obstruct the view.
What else the tester checks
- Wipers – work in at least two speeds/positions on most cars, clear the screen effectively, blades not torn or missing
- Washers – spray enough fluid to clear the screen with the wipers (an empty washer bottle fails)
- Mirrors – the required mirrors present, secure and not damaged so as to impair the view
- Obstructions – stickers, dashcams, sat-navs, phone holders and air fresheners in the swept area can fail if they seriously obstruct the driver's view
- Bonnet – must latch securely
- Front glass – front windscreen and front side windows must not be excessively tinted
Common visibility failures
| Defect found | Usual category |
|---|---|
| Windscreen damage over 10mm in zone A | Major |
| Windscreen damage over 40mm elsewhere in swept area | Major |
| Wiper blade missing or not clearing the screen | Major |
| Washer not supplying fluid (including empty reservoir) | Major |
| Driver's view seriously obstructed by an object | Major |
| Required mirror missing, insecure or seriously damaged | Major |
| Bonnet not latching securely | Major |
Repair costs
| Repair | Typical cost | DIY? |
|---|---|---|
| Wiper blades (pair) | £10–£40 | Yes |
| Screen wash | £3–£8 | Yes |
| Washer pump | £30–£90 | Often |
| Wiper motor | £100–£300 | Sometimes |
| Windscreen chip repair | £0–£80 (often free through insurance) | No |
| Windscreen replacement | £200–£500; £600–£1,200+ with ADAS camera calibration | No |
| Door mirror glass | £20–£60 | Yes |
| Complete door mirror | £80–£350 | Often |
Typical UK independent garage prices including parts, labour and VAT, 2026. Main dealers and premium/4x4 vehicles cost more.
Check your insurance before paying for a screen
Most comprehensive policies include windscreen cover with a small excess, and chip repairs are often free with no effect on your no-claims bonus. Cars with lane-keeping or emergency braking cameras need the camera recalibrated after a new screen, which adds cost.
Free retest
Windscreen glass, wipers, washers and mirrors are all on the free next-working-day retest list.
Questions people ask
What size windscreen chip fails an MOT?
Over 10mm in the 290mm-wide zone directly in front of the driver, or over 40mm anywhere else in the area swept by the wipers.
Will an empty washer bottle fail the MOT?
Yes. If the washers don't supply enough fluid to clean the screen, it's a major defect. Top it up before the test.
Can a dashcam fail an MOT?
Only if it seriously obstructs the driver's view within the swept area. Mount it behind the rear-view mirror where it's out of the way.