MOT test garages pass one in 10 cars that should fail

Research reveals there could be 1.29 million unroadworthy and potentially dangerous cars being driven on the UK’s roads...

MOT compliance

One in 10 cars that passed their MOT last year should have failed, because garages failed to uphold Government testing standards, a What Car? investigation has revealed.

Likewise, 2% of cars that failed should actually have passed. With 26.6 million cars over three years old that need an MOT test every year, that means there could be 1.29 million vehicles being driven on UK roads with potentially dangerous defects. 

These figures are based on the findings of a Driver and Vehicle Standards Agency (DVSA) report, which we obtained via a Freedom of Information request.

As part of its 2021-2022 MOT Compliance Survey (the most recent conducted), a team of DVSA expert examiners retested a randomly selected sample of 1732 vehicles at the sites where the vehicles were originally assessed.

MOT garage sign

The aim of these annual inspections is to establish if the correct test standards are being applied. But the DVSA examiners disagreed with the MOT test outcomes in 12% of instances, saying that 2% of the cars that had failed were actually worthy of a pass certificate, and that 10% of the cars passed by MOT testers should have failed.

These number are slightly better than those from the previous time the tests were carried out. In 2019-2020, 13.5% of cars that should have failed were given a pass, and 3% of cars failed when they should have passed. (There is no data for 2020-2021 due to the Covid-19 pandemic.)

However, the latest data also revealed that three or more failworthy defects were found on more than half (52%) of the vehicles the MOT testers had incorrectly allowed to pass. Of that same group, 24% had two incorrectly diagnosed defects and 25% had one wrongly categorised fault.

Most worryingly of all, the most commonly overlooked fail items were tyres and brakes, both of which are safety-critical components. MOT testers didn’t apply the correct test standard relating to tyre condition in 59% of cases; that’s 734 of the cars examined. Defects with braking systems were incorrectly diagnosed in 58% of cases (660 cars). 

MOT compliance

The DVSA took action against many of the garages that were found to not be sticking to the correct MOT test standards. It instigated disciplinary actions against 27 garages and wrote 164 advisory warning letters to others. However, not all MOT test errors resulted in disciplinary outcomes, and no action was taken in cases where the examiners believed the errors to be marginal. 

A DVSA spokesperson said: “Our MOT Compliance Survey is an essential tool helping us to make our roads among the safest in Europe. The vast majority of MOT testers carry out testing to the highest standards.  

“We are delighted to see that standards have improved since the last report. This underlines the importance of DVSA taking action on the survey results and supporting testers with new digital tools, as well as demonstrating the hard work of MOT testers.”

Most common areas where DVSA disagreed with MOT test station 

Defect category Number of defecs disagreed
Tyres 734
Brakes  660
Suspension 642
Lights, reflectors and electrics 422
Noise, emissions and leaks 171
Body, chassis and structure 164
Visibility 142
Steering  92
Vehicle identification 46
Seatbelts 45
Wheels 27

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