> ## Documentation Index > Fetch the complete documentation index at: https://docs.shieldgps.com/llms.txt > Use this file to discover all available pages before exploring further. # Geofences: Alerts When Your Tracker Enters or Exits > Draw a virtual boundary on the map and receive instant alerts whenever your ShieldGPS tracker enters or exits the zone you define. A geofence is a virtual boundary you draw on the map. When your tracker crosses that boundary — either entering or leaving — ShieldGPS sends you an instant notification. Geofences are one of the most powerful tools for protecting your assets and staying informed without having to watch the map constantly. ShieldGPS geofence editor showing a custom boundary being drawn on the map ## Create a Geofence Launch the ShieldGPS app on iOS or Android, or sign in at [shieldgps.co/dashboard](https://shieldgps.co/dashboard). Tap the device you want to set the geofence for. On the web dashboard, click the geofence editor button — the map pin with a pencil — on the right side of the map. In the mobile app, open the device details and tap **Geofences**. ShieldGPS map controls with an annotation pointing to the geofence editor button Tap the **Add** or **+** button to start creating a new zone. Pan and zoom the map to your desired location. You can draw a custom polygon around an area or drop a circular zone and drag the radius handle to set the size. ShieldGPS geofence editor showing a custom boundary being drawn on the map Give the zone a clear, descriptive name — for example, *Home*, *Warehouse*, or *School*. ShieldGPS new geofence form showing the name field, entry and exit alert settings, and Save button Select one or more trigger types: * **Entry alert** — notify me when the tracker enters this zone * **Exit alert** — notify me when the tracker leaves this zone * **Both** — notify me on entry and exit Tap **Save**. The geofence is now active and will start monitoring straight away. ## Edit or Delete a Geofence To change an existing geofence, go to **Geofences** for the relevant device, tap the geofence name, and select **Edit**. You can resize the zone, move it, rename it, or change the alert triggers. To remove a geofence entirely, tap **Delete** from the same screen. ## Multiple Geofences You can have as many geofences active at the same time as you need — there is no limit per device. Each geofence operates independently, so you can set different triggers for different zones on the same tracker. ShieldGPS map showing multiple active geofences highlighted as red boundary areas ## Common Uses Know the moment a vehicle leaves your property outside of expected hours. Confirm when a child or vehicle arrives at and departs from a school zone. Monitor assets entering and leaving your storage or distribution site. Track when equipment or vehicles arrive at or leave a work site. ## Notification Delivery When a geofence trigger fires, ShieldGPS delivers an alert in the following ways: * **Push notification** — sent to your iOS or Android device via the ShieldGPS app * **In-app alert** — visible in the notification centre within the app and web dashboard Make sure notification permissions are enabled for the ShieldGPS app in your phone's system settings to receive push notifications reliably. Create a geofence around your vehicle's usual parking spot to get instantly alerted if it moves unexpectedly — one of the most effective early-warning signals for vehicle theft.