Furnishing wrong information to get cheap car insurance is a "false economy" that can prove costly for motorists in the long run, a trade body has warned.
The Association of British Insurers (ABI) said its study found thousands of drivers would consider keeping back details such as motoring convictions or lying about personal details to bring down their premiums.
It may end up invalidating their insurance cover, which means providers can refuse to pay out on claims, the ABI said.
Such drivers also risk criminal convictions and difficulties obtaining insurance and other financial products in the future, as well as high premiums.
More than half of people the ABI surveyed consider 'fronting' as borderline or acceptable. This is fraud that occurs when a young person is the main driver of a car but a parent takes out an insurance policy in their name.
A fifth of drivers would not mind securing lower premiums by lying about the number of years since their last insurance claim, and 12% said they would think about not disclosing any relevant convictions for motoring offences.
A further one in 10 drivers said they would not rule out changing details, such as their age, address or occupation, if it enabled them to get cheaper cover.
Nick Starling, the ABI's director of general insurance and health, said: "Trying to deceive your insurer is a false economy that will cost you dear."