MOT Failure Reasons Explained

If your car is over three years old, it needs a valid MOT each year to be driven legally on UK roads. Knowing the most common failure points helps you prepare — and often fix small issues before the test.

The most common MOT failure reasons

Year after year, the same handful of issues account for most failures. The good news is that many are inexpensive to put right:

• Lighting and signalling — blown bulbs are one of the single biggest causes of failure.
• Suspension — worn components and knocks.
• Brakes — worn pads or discs, imbalance, or low brake fluid.
• Tyres — below the 1.6mm legal tread limit, or damage.
• Visibility — wipers, washers and obstructed view of the road.
• Exhaust and emissions — leaks or readings outside limits.

How to reduce your chance of failing

A quick pre-MOT check can save you a retest: walk round the car checking all lights, top up screen wash, check wiper blades, look at tyre tread and condition, and listen for any unusual brake noise. If something is worn, it is usually cheaper to fix it before the test.

What happens if my car fails?

If your car fails, you will get a list of the failure items. Any repairs needed to pass require your approval before work goes ahead. Once repaired, the vehicle is re-tested. You must not drive a car with a failed MOT and no valid certificate, except in limited cases such as driving to a pre-booked repair or test.

MOT cost

The maximum fee a test station can charge for a standard car (class 4) MOT is set by the government at £54.85, though many charge less. Repairs to fix failures are separate and depend on what is needed.

Frequently asked questions