How many mirrors does the law require, what counts as damage versus advisory, and what really changed in the January 2026 MOT updates.
Wing mirrors are MOT inspection items. They have been for decades. What confuses people is which mirror is mandatory, what counts as damage versus advisory, and whether the 2026 MOT rule changes affect the mirror checks. Here is the actual position as of January 2026.
How many mirrors does the law require
For passenger vehicles first used on or after the twenty sixth of January 2010, you need three mirrors. One driver side door mirror, one passenger side door mirror, one interior mirror. The only exception is if the interior mirror genuinely cannot see anything useful out of the back. Vans with no rear window are the obvious case. They are exempt from the interior mirror requirement.
Vehicles registered before that date need two mirrors total. The driver side door mirror is always mandatory. The second can be either the passenger side door or the interior mirror.
What a tester actually checks
The MOT inspection manual, section three on visibility, lists three things for each mirror.
- Presence. The mirror exists where it should.
- Security. The mirror is rigidly mounted and does not flop around in the wind.
- View. The glass is not so damaged that you cannot see a useful rearward image.
That last one is the grey area. A small crack in the corner of the glass that does not obscure the main field of view is an MOT advisory, not a fail. A crack across the centre that breaks up the reflection is a fail. Same with missing chunks, deeply scratched silver backing, or fogging from delamination.
The MOT does not require the heated function or the electric adjustment to work. Only the visibility matters. You can pass the test with a heated mirror that no longer heats. That said, fixing the heater is usually cheaper than replacing the whole glass once it has fogged.
Driving without a passenger side mirror
If your passenger side mirror is missing entirely on a vehicle registered after January 2010, you have an MOT fail and a potential moving traffic offence. The exception is older vehicles or specific commercial setups where the interior mirror covers what the side would have shown. For practical purposes, replace it.
What changed for 2026
The MOT updates that came into force in January 2026 are mostly about tester accreditation and equipment standards, not the items being checked. For wing mirrors specifically, the inspection criteria are unchanged. The headline updates relevant to drivers are stricter enforcement of tester credentials, mandatory equipment calibration logging, and tighter rules on retesting time windows. Your mirror still passes or fails on the same three criteria as before.
Self check before booking
Five minute pre MOT check anyone can do.
- Sit in the driver seat. Adjust both door mirrors to your normal position. The image of the rear of the car and the lane behind should be clear and continuous.
- Push each mirror housing firmly with your hand. There should be no play in the mounting. A wobble means a worn hinge or a damaged base.
- Walk around the car. Look at the glass in daylight. Any crack longer than your thumbnail is borderline.
- Switch heated on if fitted. Spit on the glass. Three minute test. Optional for the MOT, useful for winter.
Total cost of replacing both mirror glasses on a UK family car at home is under thirty pounds. Total cost of an MOT retest after a mirror fail is forty pounds plus the part. Sort it before the booking.
