The Most Common MOT Failures (and How to Avoid Them)

A large share of MOT failures are for simple, cheap-to-fix items that an owner could have spotted beforehand. Here are the faults that fail the most cars in the UK — and the five-minute checks that help you pass first time.

1. Lighting and signalling

Blown bulbs are consistently one of the single biggest reasons cars fail. Before a test, check sidelights, headlights (dipped and main beam), brake lights, indicators, fog lights and the number-plate light. Ask someone to watch while you work through them, or use a reflection in a window or garage door.

2. Tyres

Tyres must have at least 1.6 mm of tread across the central three-quarters, all the way round, with no serious cuts or bulges. Check the pressures too. Worn tyres are both a common failure and a safety risk.

3. Brakes

Worn pads, imbalance between sides and a weak handbrake are frequent failures. If you hear grinding or squealing, feel vibration through the pedal, or the handbrake pulls up very high, get it looked at before the test.

4. Suspension and steering

Knocks over bumps, uneven tyre wear or a car that sits unevenly can point to worn shock absorbers, springs or bushes — a very common MOT advisory that eventually becomes a failure.

5. Driver's view of the road

Chips or cracks in the swept area of the windscreen, worn wiper blades, and a washer bottle that doesn't squirt are all easy fails. Top up the screen wash and replace tired wipers.

6. Emissions and the exhaust

An illuminated engine-management light, a blowing exhaust or excessive smoke can all fail the emissions check. A car that's been driven gently for a good run before the test often performs better.

How to see a specific car's weak spots

Different makes and models tend to fail for different reasons. Look up a vehicle's history to see which advisories and failures keep coming back for that exact car: