Over a third of motorists don't fully understand how fully comprehensive car insurance works, according to new research by insurer Churchill.

That means millions of motorists are potentially driving with invalid insurance or much lower cover than they think.

The research revealed that 35% of people with a UK driving licence think that a fully comprehensive car insurance policy covers them to drive any vehicle and be entitled to the same level of cover. The number rises to 46% for 18-34 year olds.

Less than a quarter of drivers would tell their insurer if they were planning to drive another vehicle, while only 40% checked if their policy actually allowed them to drive another vehicle.

Driving other cars

Contrary to what some drivers believe, almost no insurers offer ‘open’ cover for driving other cars (or DOC).

DOC only extends to third parties and is only intended to be used for a very short time during a policy year, such as in the case of the owner’s emergency illness.

A third of the licenced drivers surveyed believed that they could drive another vehicle with no restrictions whatsoever. Just 12% of them understood that it’s just for a limited time, while only 16% knew that it would be restrictedthe policy was limited to emergencies only.

Rob Miles, director of motor at Churchill Insurance, said it was "worrying" that few drivers understood that a fully comprehensive policy did not cover every driver in every situation. He added: "Uninsured motorists drive up the cost of insurance premiums for all other drivers and ignorance is no excuse."

The table below breaks down which drivers are most likely to be confused about what fully comprehensive policies cover on a regional basis.

Region

Percentage of licence holders who believe they can drive any vehicle with a fully comprehensive policy

Scotland

42%

Yorkshire and the Humber

42%

North East

42%

London

38%

South East

37%

South West

34%

East Midlands

33%

West Midlands

33%

Wales

31%

East of England

30%

North West

28%

Source: Churchill Car Insurance

[Related story: Is age the biggest factor in determining your car insurance costs?]

What does a fully comprehensive car insurance policy actually cover?

Even though it doesn’t cover you in other vehicles, fully comprehensive car insurance is still the most complete cover out there.

It includes third-party liability as well as damage to other people’s property. What’s more, your own car is covered against fire, theft and accidental damage. 

Some may even come with a courtesy car if your own vehicle is out of action.

However, it is the most expensive cover going. You can bring the price down by buying a lower-risk vehicle, parking in safe places and keeping your mileage down.

Compare car insurance policies and see if you could save