Top causes of MoT failure revealed

Almost a fifth of failed MoTs are due to faulty lights, with brakes and suspension not far behind

An analysis of data from the Vehicle Operator and Services Agency (VOSA) has revealed the most common reasons for MoT failures.

Faulty lamps, reflectors and electrical equipment were responsible for 19% of all MoT failures, with over 80,000 cars needing a retest. Duff brakes to blame for stopping 14% of cars passing, and subpar suspension racked up 12% of failures.

The study was carried out by servicing and MoT comparison website, and involved crunching numbers from almost 30 million MoTs from 2015 – the latest year for which figures are available. After lights, brakes and suspension, “driver’s view of the road” was the next biggest stumbling block – this covers everything from large cracks in the windscreen, to dashcams, stickers and other obstructions blocking the view out.

Tired tyres caused one in 10 cars to fail, problems with emissions and fuel systems were responsible for another 8%, with steering sending 7% of cars back to the garage and seatbelts a further 5%.

Reason for Rejection



Lamps, Reflectors & Electrical Equipment 80,026


Brakes 59,133


Suspension 53,322


Driver's view of the road 47,662


Tyres 42,193


Exhaust, Fuel & Emissions 32,893


Steering 29,101


Seatbelts & Restraint Systems 22,824


Body Structure & General Items 22,566


Reg Plates & VINs 17,655


Road Wheels 10,520


Items not tested 8,812


Towbars 2,827


Driving Control and Speed Limiters 206


While problems with emissions may only be detectable with specialist equipment, the fact the number-one cause of MoT failure is faulty lighting should give owners even more reason to check their cars over before test time comes around.

Faulty lights are usually easily rectified by a service centre on the spot, and retests for minor issues will be free, but if the requisite bulb is out of stock, you could be left without a road-legal car. It’s also worth pointing out that changing some headlight bulbs can be an involved process that requires removing the bumper. If this is the case, factor in an hour’s labour charge.

To give your car its best shot at passing first time, make your way over to our MoT checklist, or if the prospect of dealing with mechanics’ jargon leaves you cold, head over to our terminology guide.

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