You should inform your insurance company right away. Make sure you've gotten a copy of the police report and the other party's (or parties') insurance information. If possible, take pictures of all vehicles involved in the accident, to prevent the other parties from claiming damage to a vehicle that was not related to the accident.
Remember, just because you inform your insurer of an accident doesn't mean you're making a claim.
British Citizens:
Canadian Citizens:
What should I do if I just had an auto accident? 
You should inform your insurance company right away. Make sure you've gotten a copy of the police report and the other party's (or parties') insurance information. If possible, take pictures of all vehicles involved in the accident, to prevent the other parties from claiming damage to a vehicle that was not related to the accident.