diff --git a/homeassistant/components/mobile_app/webhook.py b/homeassistant/components/mobile_app/webhook.py
index 16b37e5f1bb5..48e3dc1af199 100644
--- a/homeassistant/components/mobile_app/webhook.py
+++ b/homeassistant/components/mobile_app/webhook.py
@@ -55,6 +55,7 @@ from homeassistant.helpers import (
     config_validation as cv,
     device_registry as dr,
     entity_registry as er,
+    instance_id,
     template,
 )
 from homeassistant.helpers.dispatcher import async_dispatcher_send
@@ -738,6 +739,7 @@ async def webhook_get_config(
         "longitude": hass_config["longitude"],
         "elevation": hass_config["elevation"],
         "hass_device_id": device.id,
+        "instance_id": await instance_id.async_get(hass),
         "unit_system": hass_config["unit_system"],
         "location_name": hass_config["location_name"],
         "time_zone": hass_config["time_zone"],
diff --git a/tests/components/mobile_app/test_webhook.py b/tests/components/mobile_app/test_webhook.py
index 3c1ec10c93e1..1d6a26d95d3b 100644
--- a/tests/components/mobile_app/test_webhook.py
+++ b/tests/components/mobile_app/test_webhook.py
@@ -24,7 +24,11 @@ from homeassistant.const import (
 )
 from homeassistant.core import HomeAssistant, callback
 from homeassistant.exceptions import HomeAssistantError
-from homeassistant.helpers import device_registry as dr, entity_registry as er
+from homeassistant.helpers import (
+    device_registry as dr,
+    entity_registry as er,
+    instance_id,
+)
 from homeassistant.setup import async_setup_component
 
 from .const import CALL_SERVICE, FIRE_EVENT, REGISTER_CLEARTEXT, RENDER_TEMPLATE, UPDATE
@@ -297,6 +301,7 @@ async def test_webhook_handle_get_config(
         "longitude": hass_config["longitude"],
         "elevation": hass_config["elevation"],
         "hass_device_id": device.id,
+        "instance_id": await instance_id.async_get(hass),
         "unit_system": hass_config["unit_system"],
         "location_name": hass_config["location_name"],
         "time_zone": hass_config["time_zone"],