diff --git a/homeassistant/components/mobile_app/binary_sensor.py b/homeassistant/components/mobile_app/binary_sensor.py
index 289a50584c92..50943bb6504d 100644
--- a/homeassistant/components/mobile_app/binary_sensor.py
+++ b/homeassistant/components/mobile_app/binary_sensor.py
@@ -8,9 +8,10 @@ from homeassistant.helpers.dispatcher import async_dispatcher_connect
 
 from .const import (ATTR_SENSOR_STATE,
                     ATTR_SENSOR_TYPE_BINARY_SENSOR as ENTITY_TYPE,
+                    ATTR_SENSOR_UNIQUE_ID,
                     DATA_DEVICES, DOMAIN)
 
-from .entity import MobileAppEntity
+from .entity import MobileAppEntity, sensor_id
 
 DEPENDENCIES = ['mobile_app']
 
@@ -36,6 +37,16 @@ async def async_setup_entry(hass, config_entry, async_add_entities):
         if data[CONF_WEBHOOK_ID] != webhook_id:
             return
 
+        unique_id = sensor_id(data[CONF_WEBHOOK_ID],
+                              data[ATTR_SENSOR_UNIQUE_ID])
+
+        entity = hass.data[DOMAIN][ENTITY_TYPE][unique_id]
+
+        if 'added' in entity:
+            return
+
+        entity['added'] = True
+
         device = hass.data[DOMAIN][DATA_DEVICES][data[CONF_WEBHOOK_ID]]
 
         async_add_entities([MobileAppBinarySensor(data, device, config_entry)])
diff --git a/homeassistant/components/mobile_app/entity.py b/homeassistant/components/mobile_app/entity.py
index 05736b3a689b..eca9d2b024bd 100644
--- a/homeassistant/components/mobile_app/entity.py
+++ b/homeassistant/components/mobile_app/entity.py
@@ -13,6 +13,11 @@ from .const import (ATTR_DEVICE_ID, ATTR_DEVICE_NAME, ATTR_MANUFACTURER,
                     DOMAIN, SIGNAL_SENSOR_UPDATE)
 
 
+def sensor_id(webhook_id, unique_id):
+    """Return a unique sensor ID."""
+    return "{}_{}".format(webhook_id, unique_id)
+
+
 class MobileAppEntity(Entity):
     """Representation of an mobile app entity."""
 
@@ -22,8 +27,8 @@ class MobileAppEntity(Entity):
         self._device = device
         self._entry = entry
         self._registration = entry.data
-        self._sensor_id = "{}_{}".format(self._registration[CONF_WEBHOOK_ID],
-                                         config[ATTR_SENSOR_UNIQUE_ID])
+        self._sensor_id = sensor_id(self._registration[CONF_WEBHOOK_ID],
+                                    config[ATTR_SENSOR_UNIQUE_ID])
         self._entity_type = config[ATTR_SENSOR_TYPE]
         self.unsub_dispatcher = None
 
@@ -94,5 +99,10 @@ class MobileAppEntity(Entity):
     @callback
     def _handle_update(self, data):
         """Handle async event updates."""
+        incoming_id = sensor_id(data[CONF_WEBHOOK_ID],
+                                data[ATTR_SENSOR_UNIQUE_ID])
+        if incoming_id != self._sensor_id:
+            return
+
         self._config = data
         self.async_schedule_update_ha_state()
diff --git a/homeassistant/components/mobile_app/sensor.py b/homeassistant/components/mobile_app/sensor.py
index b2846a6002b1..64ad69c5758e 100644
--- a/homeassistant/components/mobile_app/sensor.py
+++ b/homeassistant/components/mobile_app/sensor.py
@@ -7,9 +7,10 @@ from homeassistant.helpers.dispatcher import async_dispatcher_connect
 
 from .const import (ATTR_SENSOR_STATE,
                     ATTR_SENSOR_TYPE_SENSOR as ENTITY_TYPE,
-                    ATTR_SENSOR_UOM, DATA_DEVICES, DOMAIN)
+                    ATTR_SENSOR_UNIQUE_ID, ATTR_SENSOR_UOM, DATA_DEVICES,
+                    DOMAIN)
 
-from .entity import MobileAppEntity
+from .entity import MobileAppEntity, sensor_id
 
 DEPENDENCIES = ['mobile_app']
 
@@ -35,6 +36,16 @@ async def async_setup_entry(hass, config_entry, async_add_entities):
         if data[CONF_WEBHOOK_ID] != webhook_id:
             return
 
+        unique_id = sensor_id(data[CONF_WEBHOOK_ID],
+                              data[ATTR_SENSOR_UNIQUE_ID])
+
+        entity = hass.data[DOMAIN][ENTITY_TYPE][unique_id]
+
+        if 'added' in entity:
+            return
+
+        entity['added'] = True
+
         device = hass.data[DOMAIN][DATA_DEVICES][data[CONF_WEBHOOK_ID]]
 
         async_add_entities([MobileAppSensor(data, device, config_entry)])
diff --git a/homeassistant/components/mobile_app/webhook.py b/homeassistant/components/mobile_app/webhook.py
index 2a3d23731cb9..1ef5f4ce5317 100644
--- a/homeassistant/components/mobile_app/webhook.py
+++ b/homeassistant/components/mobile_app/webhook.py
@@ -99,6 +99,9 @@ async def handle_webhook(hass: HomeAssistantType, webhook_id: str,
 
     data = webhook_payload
 
+    _LOGGER.debug("Received webhook payload for type %s: %s", webhook_type,
+                  data)
+
     if webhook_type in WEBHOOK_SCHEMAS:
         try:
             data = WEBHOOK_SCHEMAS[webhook_type](webhook_payload)