car insurance firms are hiking premiums by more than a third even for drivers not at fault in a crash .
Other insurers upped quotes by 33 per cent and 29 per cent for drivers in crashes not at fault.
Researchers from consumer group Which? obtained quotes from 12 major UK insurers in July and August to see what difference it would make to a premium if someone had made a claim for a minor scrape that was not their fault.
Their fictional driver was a married woman in her mid-forties, with low annual mileage, five years’ no-claims discount and a clean driving history.
Esure increased its quote by 39 per cent after a claim was added where the driver was blameless but their insurer had to pay.
More Than and Rias also upped their quotes by 33 per cent and 29 per cent respectively.
And in a scenario where repairs had been covered by another driver’s insurer, four out of 12 insurers increased the premium.
These were More Than (33%), Esure (17%), AXA (14%) and Admiral (11%).
Admiral and Esure charged extra even when researchers did not claim for an incident.
Which? said: “The difference between a car insurance ‘fault’ and ‘non-fault’ claim sounds relatively straightforward, but when we surveyed 1,281 UK drivers, only one in five understood the industry interpretation.
“Insurers don’t view ‘fault’ like normal people do. If someone damages your car, your premium can rise, even if you’re blameless – and even if you didn’t claim. Regardless of whether you’re to blame for the actual incident, you will be regarded as ‘at fault’ if your insurer has to pay for it.
“This would apply, for example, if your car was hit by another driver while parked and that other driver couldn’t be traced.”
A claim is considered ‘non-fault’ if your insurer hasn’t ultimately incurred the costs – for instance if it is able to recoup its expenses from the other driver’s insurer.
A third of motorists surveyed wrongly thought they did not need to disclose incidents where they have repaid for repairs themselves.
By law, drivers must answer all questions asked by an insurer or risk having a claim, or even their whole policy, invalidated.
Esure increased one premium by 15 per cent simply for declaring a scratch without having made a claim.
An Esure spokesman said: “This was reported as an incident, which would include a wide range of different damage scenarios, and wasn’t a specific uplift for a scratch.”