Many people are hesitant to file claims with their auto insurance company out of fear that their premiums will be increased or the policy will be cancelled. While practices vary between insurance companies, more will increase your premiums by a predetermined percentage for each chargeable claim made against your policy above a specific dollar amount.
A chargeable claim is one that an insurance company considers to primarily be your fault. Also, these premium increases will generally stay on your premium for three years following the claim.
If you have an accident but don‘t report it to your insurer, you are taking a risk, even if the damage seems minor. If the other driver sues you weeks or months later, your failure to report the accident might cause your insurer to refuse to honor the policy. And even if they do honor the policy, the delay will certainly make it harder for the insurer to gather evidence to represent you.