First of all: Make sure to distinguish between an accident and a damage of the vehicle correctly.
Accident: Any damage that occured while your rent was active.
Damage: Any damage that occured before your rent has started.
Keep calm, secure the scene of the accident if necessary (warning vest and warning triangle are in the glove compartment and the trunk), and provide first aid. Then call 110 (WHERE did WHAT happen? Wait for questions) and only then inform us at +49 (0) 30 / 2016 4975, we will help you. Please do not leave the scene of the accident, but wait until the police are on site.
PLEASE MAKE SURE TO CONTACT THE POLICE IN ANY CASE, NO MATTER IF JUST YOU OR MULTIPLE PEOPLE / VEHICLES ARE INVOLVED!