The most common MOT failures and how to avoid them
Updated September 2026
DVSA figures consistently show the same few areas cause most failures: lighting and signalling, suspension, brakes, tyres, and the driver's view of the road. Many of these are cheap and quick to fix before the test.
Lights and signalling
A single blown bulb is a fail. Walk around the car with the lights, indicators and hazards on, and ask someone to watch the brake lights as you press the pedal. Don't forget the number plate lamp.
Tyres
The legal minimum tread is 1.6mm across the central three-quarters of the tyre, all the way round. Put a 20p coin in the groove: if you can see the outer band, the tyre may be close to the limit. Look for cuts and bulges in the sidewall too.
Driver's view of the road
Chips or cracks larger than 10mm directly in front of the driver, or 40mm elsewhere in the area the wipers clear, cause a fail. Split wiper blades and an empty washer bottle are also failures, and both are easy to fix at home.
Brakes and suspension
These need a garage to inspect properly. If your last MOT had advisories for brake discs, pads, springs or bushes, have them looked at before the test. Many garages offer a free pre-MOT check when you book the MOT.
Warning lights
An ABS, airbag or power steering warning light that stays on can fail the test. Have warning lights diagnosed before the MOT, not on the day.
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Official rules: GOV.UK: Getting an MOT.