Can a Windscreen Chip Fail MOT? UK Rules Explained

Quick answer

A windscreen chip can fail an MOT if it is larger than 10mm in Zone A, or larger than 40mm in the rest of the windscreen’s swept area. The tester should only fail damage if it significantly affects the driver’s view of the road. :contentReference[oaicite:0]{index=0}

A small chip outside the driver’s main view may pass, but it can still become an advisory or get worse later. Repairing chips early is usually better than waiting for a crack to spread.

When windscreen damage can fail an MOT

The MOT visibility section checks windscreen condition, the driver’s view of the road, wipers, washers and related visibility issues. Windscreen damage is mainly judged by size, location and whether it affects the view.

!Damage over 10mm in Zone A: can fail if it significantly affects the driver’s view.
!Damage over 40mm elsewhere in the swept area: can fail if it affects visibility.
!Long cracks: may fail if they obstruct or significantly affect the driver’s view.
!Bad repairs: can still fail if the repair interferes with vision.
!Wiper and washer faults: can also affect MOT visibility results.

What is Zone A on a windscreen?

Zone A is the main driver’s view area. It is within the swept area of the windscreen, 290mm wide, and centred on the steering wheel. Damage in this area is treated more strictly because it can directly affect the driver’s view of the road. :contentReference[oaicite:1]{index=1}

Zone A

Main driver view area. Damage over 10mm can be a problem.

Swept area

The area cleared by the windscreen wipers. Damage over 40mm can be a problem.

Outside swept area

Still worth repairing, but usually judged differently from the main view.

Pre-MOT windscreen checks

1Look for chips, cracks or star breaks in the driver’s line of sight.
2Check whether the chip is inside the wiper-swept area.
3Check if any crack has started spreading from a small chip.
4Make sure wipers clear properly without smearing or missing areas.
5Check washer fluid sprays correctly onto the windscreen.
6Remove anything that blocks the driver’s view, such as badly placed stickers or accessories.

Should you repair a windscreen chip before MOT?

If the chip is small and repairable, fixing it before the MOT is usually sensible. A good repair that is barely detectable and flush with the surrounding glass should be judged on whether it interferes with vision, not simply because a repair exists. :contentReference[oaicite:2]{index=2}

Repair may be enough

Small chips can often be repaired if they are not too large or badly cracked.

Replacement may be needed

Long cracks, spreading damage or severe damage may need a replacement windscreen.

Other visibility issues that can fail an MOT

A windscreen chip is not the only visibility issue checked during an MOT. Wipers, washers, excessive tinting, discolouration and damage to windows near the driver can also matter.

✓Wipers not clearing the screen properly.
✓Washer jets not working or washer bottle empty.
✓Objects or stickers blocking the driver’s view.
✓Excessive tinting or discolouration affecting visibility.

Frequently asked questions

Can a small windscreen chip fail MOT?

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

What size chip fails MOT?

Damage over 10mm in Zone A or over 40mm in the rest of the swept area can fail if it affects the driver’s view.

Can a repaired chip pass MOT?

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

Can a cracked windscreen fail MOT?

Yes. A crack can fail if it significantly affects the driver’s view or falls within the relevant size and location rules.

Do wipers matter for MOT?

Yes. Wipers and washers must work well enough to give the driver a clear view.

Should I repair a chip before MOT?

Usually yes, especially if it is in the driver’s view or starting to spread.

Can a Windscreen Chip Fail MOT?