An insurance company for many reasons. Sometimes, the insurance company just does not want to pay the claim and hope that when they initially say No, that you will simply go away. They can also potentially deny your claim if there is evidence that more than one person is at fault for the incident. Multiple people can be at fault for an accident and an insurance company will want to fully investigate your involvement with the incident. There can be various disputes as to the liability of the case and the insurance company can deny your claim if there is an indication that the policyholder is not responsible. There can also be issues with the extent of the injuries suffered during the accident. If the insurance company does not believe the injuries to be as severe as claimed, they are able to refuse your request. Be sure to have viable proof of your injuries sustained from an accident.