Quick answer
Yes, a cracked mirror can fail an MOT if the damage prevents the mirror from giving a clear view, the mirror is missing, loose, insecure or dangerous.
A tiny crack or cosmetic damage may not automatically fail, but any damage that affects visibility or safety should be repaired before the MOT.
When a cracked mirror can fail MOT
View is distorted
Cracked or damaged glass may stop the driver seeing clearly behind or beside the car.
Mirror glass is missing
Missing mirror glass is much more likely to cause a failure.
Mirror is insecure
A loose mirror housing can fail if it is not safely attached.
Sharp edges
Broken plastic or glass with sharp edges can be considered dangerous.
Required visibility lost
The vehicle must have adequate rearward visibility through required mirrors.
Mirror cannot adjust
A mirror stuck in a poor position may not give the driver the required view.
When a cracked mirror may still pass
A small crack or cosmetic damage may not fail if the mirror remains secure, gives a clear view and has no dangerous sharp edges.
However, MOT judgement can depend on the exact damage, mirror position and whether the driver still has the required view. If the crack distracts you or distorts the image, repair it before the test.
What to check before the MOT
1. Check the glass
Look for cracks, missing sections, loose glass or distortion.
2. Check the housing
Make sure the mirror body is securely fixed and not hanging loose.
3. Adjust the mirror
Confirm it can be adjusted to give a proper rearward view.
4. Look for sharp edges
Broken casing or glass may create a safety issue.
5. Check both sides
Do not only check the damaged mirror; make sure all mirrors work properly.
6. Fix cheap damage early
Replacement mirror glass is often cheaper than risking a fail and retest.
Should you fix a cracked mirror before MOT?
Usually, yes. Mirror damage is often simple and relatively inexpensive to repair compared with the hassle of an MOT failure.
If only the glass is damaged, replacement stick-on or clip-in mirror glass may be enough. If the housing is broken, loose or sharp, the complete mirror assembly may need repair or replacement.
Can you drive with a cracked mirror?
Driving with a badly cracked or missing mirror can reduce visibility and make lane changes, reversing and parking more dangerous.
If the mirror no longer gives a clear view, repair it before driving regularly.
Related MOT and safety guides
Frequently asked questions
Will a cracked wing mirror fail MOT?
It can if the crack affects visibility, the mirror is insecure or sharp edges are present.
Can I pass MOT with cracked mirror glass?
Possibly, if the view is still clear and the mirror is secure, but repair is safer.
Will a missing wing mirror fail MOT?
It is much more likely to fail if the vehicle no longer has the required rearward view.
Does broken mirror casing fail MOT?
It can if the casing is loose, insecure or has dangerous sharp edges.
Is stick-on mirror glass acceptable?
It may be acceptable if secure, correctly fitted and gives a clear view.
Should I repair it before the test?
Yes, especially if the damage affects visibility or the mirror is loose.