In most states if you are involved in a collision of any type on a public road you are required to report it to the police. This of course can vary state to state but this is the general rule. If you are involved in an accident on private property the rules can be considerably different and there may not be a requirement to file a report.However, as others have indicated, it is nearly always in your best interest to file a police report. Even on private property, where the police are not going to write anyone a ticket, having that report protects you.First it prevents someone from claiming hit and run.Secondly it locks in a record of events, the story you and the other party tell the police are part of the report (often in a form you fill out) and this makes it much harder for the other person to change their mind later.Lastly the police will actually verify the information of the other person in the accident. They show you their drivers license and give you a name and addressu2023 and a copy of an insurance card. How do you have any clue if any of this is accurate or even valid. The police can check and normally do as the course of any accident investigation. If you just get info and drive off and find it is all false later you are up a creek. If they give fake info to a police officer they may end up in the back of their car.