Wireless systems communicate through radio signals and may reduce the need to run cables through finished walls. They can be suitable for existing homes where access is limited. Wireless sensors usually require batteries that must be checked and replaced periodically. Signal strength, building materials, distance and interference can also affect performance. A fixed electrical supply may still be required for the alarm panel, siren, communications equipment or other central components.

Some systems can communicate with a professional monitoring service that responds according to an agreed procedure when an alarm is activated. Monitoring availability, response arrangements, communication methods, fees and contracts are managed by the selected licensed security provider. Homeowners should review these details before choosing a monitored system.