That would depend on the type of alarm.... you might want to contact the alarm company and let them know the house has changed hands. Because if the alarm is set off by accident, the alarm company will need authorization from the last known account holder to cancel the call. So if you set it off and you arent registered with the alarm company the cops will turn up at your house no matter what you tell the alarm company and then you will be charged for the false alarm (by both the RCMP and the alarm company).