The BACnet Notification Class object defines who must receive alarm notifications (Recipient_List), with what priority, and whether acknowledgement is required.

A Notification Class is the central configuration for alarm routing. The key properties are Recipient_List (the list of destinations, defined either by Device + Process_ID or by a direct address, filterable by day of week and time of day), Priority (a 0-255 ordering value) and Ack_Required (which event transitions among TO_OFFNORMAL, TO_FAULT and TO_NORMAL must be acknowledged by a user). Risk-bearing objects (an AI for a temperature probe, a BV for an intrusion alarm) reference a Notification Class through their Notification_Class property. This allows centralised, configurable alarm-flow management.

Always create at least three Notification Classes (critical, standard, info) on day one: refactoring the alarm routing later when 500 points already reference Notification Class 1 is a painful migration.