The study has found that almost a quarter of MOTs carried out last year took place after the previous service had expired.
Almost one in ten MOT tests were more than a month overdue, the research found.
Analysis by breakdown provider Green Flag found that 3.6 million vehicles were late for their MOT in the first six months of 2024.
Further research shows that a third of drivers wrongly believe it is legal to drive without a valid MOT, as long as they have a test booked.
What can fail an MOT test?
Driving on UK roads without a valid MOT certificate is illegal, with motorists facing a fine of up to £1,000 if they do.
Driving without a valid MOT is only permitted if you are driving to a pre-arranged MOT test, or a garage for repairs after a failed MOT.
There is no grace period for expired MOTs, a car becomes illegal to drive at midnight on the MOT expiry date.
Those caught without a valid MOT can face hefty fines, vehicle impoundment, penalty points, and potentially lose their driving license if the vehicle is found to be dangerous.
How you can avoid MOT fines
Find out when your MOT is due
As soon as your car hits three years-old, it will need an MOT before its birthday each year.
You can easily check when your MOT is due using your number plate on GOV.UK.
You can undertake your MOT test up to a month (minus a day) before its expiry date while still preserving its annual due date.
Set up a reminder
Simply set a reminder on your email calendar – or in Great Britain, you can sign up online to get a free text or email reminder one month before your vehicle’s MOT is due.
In Northern Ireland you’ll get a letter in the post seven weeks before your MOT is due.
Create a car contingency account
Cars are expensive – there’s no denying that – and MOTs can throw up unexpected repair costs in order to pass.
It’s a good idea to set up a car contingency savings account; putting aside a little each month to spread the costs and make sure you can afford any unexpected nasty surprises.
Shop around for your MOT
Just as you should shop around for a cheaper premium on your car insurance, you can also compare prices for your MOT.
The maximum price of an MOT is £54.85 for a car and £29.65 for a standard motorcycle.
But many garages will offer it cheaper than this – especially if bought in conjunction with your regular servicing.
