State laws differ however normally an insurance company does not inform the Department of Motor Vehicles (DMV) about accidents. You may need to check to see if your state requires you to report an accident to the DMV though since some states require this if the damage sustained was over a certain amount.

For example according to the California Department of Motor Vehicles each driver involved in an accident that caused more than $750 worth of property damage or injured or killed any person must complete a Traffic Accident Report form SR1 to DMV within 10 days.

If the accident is not reported to the DMV then it is unlikely that it would end up on a vehicle history report such as Carfax. Carfax states that they receive in information from thousands of sources including all DMVs in the United States and Canada, as well as many vehicle inspection stations, auto auctions, fleet management and rental agencies, automobile manufacturers, and fire and police departments.

For example from state title records they receive in information about branded titles (salvage, etc.), certified odometer readings and City/State of Owner Liens. From Extended service companies information on major repairs and from police departments (selected states only) Carfax gets in accident reports.