'Mice chewed up my BMW causing £15k of damage – now my insurer won't pay out'

Has a company treated you unfairly? Our consumer champion, Katie Morley, is here to help. For how to contact her click here.  

Dear Katie,

I visited my son in Australia earlier this year and left my BMW parked in my garage for just over a month while I was gone.

Two days after I returned home it broke down. I took it to a local BMW dealership, which identified a problem with the gear selector lever.

Mechanics found that mice had eaten through its wiring, as well as the wiring to the airbag activator underneath the driver’s seat. They estimated the cost of the damage at £15,285.

I notified my insurer, Aviva, but it refused to pay out. It said the damage was not caused by a “one-off event” and therefore amounted to gradual wear and tear, which my policy does not cover. It has offered me £100 in compensation, which I have rejected.

RW, Berks

Dear RW,

Aviva refused to pay out because your policy doesn’t cover loss or damage that occurs “gradually”, such as old tyres wearing thin or bodywork rusting. It only covers damage caused by “single events”, such as a crash or a scrape. And it has decided that this mouse infestation is a gradual process rather than a single event.

How long does a single event have to last before Aviva redefines it as a gradual process? This is a grey area open to interpretation.

BMW engineers who inspected your car identified two mouse nests and extensive damage across numerous areas. You supplied me with a video documenting this and I can confirm that the mice appear to have had an absolute field day.

Rodents were present in the vehicle for a period of time before the damage became apparent, the engineers said.

Based on this, Aviva claims the damage occurred gradually. But how could the insurer reach this conclusion on the basis of a vague statement by a mechanic and without consulting the opinion of a mouse expert?

I decided it was time to bring in the pest controllers at Rentokil, who have extensive expertise in this area. They told me a month was ample time for mice to nest and breed, as their gestation period is just 21 days.

Speaking from experience, they said it would have been possible for a single mouse to cause extensive wire damage within a matter of days. More than one mouse chewing away could quickly devastate a vehicle.

Crucially, they also advised that mice far preferred stable environments to ones where there were regular sudden movements, so the damage to your BMW was most likely to have been caused while it was undisturbed in the garage rather than when you were driving it around regularly.

I can’t see how you could have done anything while in Australia to stop these little devils doing their worst to your car.

Armed with this information, I suggested to Aviva that this mouse infestation ought to be classed as a single event for insurance purposes. Thankfully, the underwriters at Aviva had a change of heart.

Given the unusual circumstances and because it now agrees that you wouldn’t have known the damage was occurring at the time, Aviva has accepted that its initial decision wasn’t “in the spirit of its policy”.

It has agreed to pay you £15,285 to cover the damage. I also understand that you are, very sensibly, taking steps to ensure your furry friends don’t return for seconds.

The full Katie Morley Investigates column will appear in print every Saturday and Sunday. You can get an early taste every Friday at 1200.

For the week’s most important personal finance news, analysis and expert advice, from pensions and property to investment ideas and savings tips, sign up to our weekly newsletter.