Windscreen chips and cracks: will your car pass its MOT?
A car will fail its MOT if windscreen damage in zone A exceeds 10 mm or damage elsewhere in the swept area exceeds 40 mm and significantly affects the driver’s view of the road.
What the MOT checks on your windscreen
Inspectors sit in the driver’s seat and check the view through the windscreen and the windows on either side of the driver. They look for damage, excessive tinting or discolouration that affects vision. The test covers all windscreens including those that open. Only defects that seriously restrict the driver’s view of the road are considered. Items such as sat navs or air fresheners can be removed before inspection if they obstruct the view. The inspector also checks the field of vision through the front side windows and notes any obstructions that affect the view in front or to the sides.
Zone A and the swept area rules
Zone A is the 290 mm wide area centred on the steering wheel within the swept area of the wipers. Damage here must be no larger than 10 mm. Outside zone A but still in the swept area the limit is 40 mm. The inspector checks the condition of the windscreen and the windows on either side of the driver’s seat. Additional interior mirrors and externally mounted items are not part of the test. You should only fail the windscreen if the view is significantly affected. If only the driver’s view of the sky or the bonnet is affected it should not be rejected.
When damage leads to failure
Failure occurs only when the damage significantly affects the driver’s view of the road. Repaired windscreens are judged on whether the repair interferes with vision. An invisible repair finished flush with the glass does not count as damage. Vehicles first used from 1 June 1978 must have windscreens and windows on either side of the driver’s seat made from safety glass. Opaque edging or split windscreens may also be noted if they affect the view. An obstruction within the driver’s field of view that significantly affects the driver's view in front or to the sides outside the swept area of windscreen is a minor defect while one that affects the view through the swept area is major.
How to inspect your own windscreen
Sit in the driver’s seat and check the road view and the view of the mandatory mirrors. Look for chips, cracks or obstructions inside the swept area. Check for damage in zone A more than 10 mm in diameter and damage in the remainder of the swept area more than 40 mm in diameter. Remove any items that block the view before the test. You do not need to consider the effects on tall or short drivers. Check the driver’s field of vision through the windscreen and through the front side windows. The following are only considered a defect if they seriously restrict the driver’s view such as taxi signs sun visors that cannot be stowed or windscreen wipers that stop in a position obscuring the view.
Keeping the glass clear before the test
Regular cleaning removes oil film and road grime that can worsen visibility. Using a rain repellent helps water bead and run off while a dedicated oil-film remover tackles stubborn residue that builds up over time. A long-handle cleaner or extendable brush reaches the full swept area without streaks. These steps help maintain a clear view through the windscreen and side windows for the MOT inspection. Clean the glass thoroughly in advance so any existing damage is easy to assess and the overall view remains unobstructed during the test.
Shop the kit
Windscreen rain repellent with sponge
Windscreen oil film remover with sponge
Windscreen cleaner with long handle
Extendable Windscreen Cleaning Brush
Windscreen Rain Repellent Spray – Nano Coating, 100ml
Car Windscreen Oil Film Cleaning Brush
Silicone Car Window Cleaning Wiper
Check your MOT and tax status free at https://www.checkmot.com.
Checked on 17 October 2026 against MOT inspection manual, section 3 Visibility (GOV.UK) https://www.gov.uk/guidance/mot-inspection-manual-for-private-passenger-and-light-commercial-vehicles/3-visibilityFrequently asked questions
Does a small chip in zone A always fail the MOT?
No. A chip must be larger than 10 mm and significantly affect the driver’s view to cause failure.
Can I repair a windscreen before the MOT?
Yes. A repair that is invisible or flush with the glass does not count as damage.
Will tinting on the windscreen cause a fail?
Only if the tinting or discolouration significantly affects the driver’s view of the road.
Do side windows next to the driver get checked?
Yes. Damage or excessive tinting on windows on either side of the driver’s seat is inspected.