Personally, I wouldn't even tell them. Your insurance will use it as a partial excuse to put up your premium, EVEN though it wasn't your fault. Had this once, and when I questioned them they said as, even though it's not your fault, it's seen as an indication there will be a claim one day soon. No shit, and one day I will die, but it doesn't mean it will be next week! Quite recently we had a van hit up the arse and the insurance doubled our premium!! Not with them now, obviously.....