diff --git a/homeassistant/components/mobile_app/config_flow.py b/homeassistant/components/mobile_app/config_flow.py
index bc9c6167da8..f06754b5bec 100644
--- a/homeassistant/components/mobile_app/config_flow.py
+++ b/homeassistant/components/mobile_app/config_flow.py
@@ -1,7 +1,7 @@
 """Config flow for Mobile App."""
 from homeassistant import config_entries
 
-from .const import ATTR_DEVICE_NAME, DOMAIN
+from .const import ATTR_DEVICE_ID, ATTR_DEVICE_NAME, DOMAIN
 
 
 @config_entries.HANDLERS.register(DOMAIN)
@@ -23,6 +23,8 @@ class MobileAppFlowHandler(config_entries.ConfigFlow):
 
     async def async_step_registration(self, user_input=None):
         """Handle a flow initialized during registration."""
+        await self.async_set_unique_id(user_input[ATTR_DEVICE_ID])
+
         return self.async_create_entry(
             title=user_input[ATTR_DEVICE_NAME], data=user_input
         )
diff --git a/homeassistant/components/mobile_app/const.py b/homeassistant/components/mobile_app/const.py
index 720cf7106e7..5a5b86269af 100644
--- a/homeassistant/components/mobile_app/const.py
+++ b/homeassistant/components/mobile_app/const.py
@@ -25,6 +25,7 @@ ATTR_DEVICE_ID = "device_id"
 ATTR_DEVICE_NAME = "device_name"
 ATTR_MANUFACTURER = "manufacturer"
 ATTR_MODEL = "model"
+ATTR_MODEL_ID = "model_id"
 ATTR_OS_NAME = "os_name"
 ATTR_OS_VERSION = "os_version"
 ATTR_PUSH_TOKEN = "push_token"
diff --git a/homeassistant/components/mobile_app/http_api.py b/homeassistant/components/mobile_app/http_api.py
index 717413f889a..7dbe7cb069c 100644
--- a/homeassistant/components/mobile_app/http_api.py
+++ b/homeassistant/components/mobile_app/http_api.py
@@ -21,6 +21,7 @@ from .const import (
     ATTR_DEVICE_NAME,
     ATTR_MANUFACTURER,
     ATTR_MODEL,
+    ATTR_MODEL_ID,
     ATTR_OS_NAME,
     ATTR_OS_VERSION,
     ATTR_SUPPORTS_ENCRYPTION,
@@ -40,18 +41,23 @@ class RegistrationsView(HomeAssistantView):
     name = "api:mobile_app:register"
 
     @RequestDataValidator(
-        {
-            vol.Optional(ATTR_APP_DATA, default={}): dict,
-            vol.Required(ATTR_APP_ID): cv.string,
-            vol.Required(ATTR_APP_NAME): cv.string,
-            vol.Required(ATTR_APP_VERSION): cv.string,
-            vol.Required(ATTR_DEVICE_NAME): cv.string,
-            vol.Required(ATTR_MANUFACTURER): cv.string,
-            vol.Required(ATTR_MODEL): cv.string,
-            vol.Required(ATTR_OS_NAME): cv.string,
-            vol.Optional(ATTR_OS_VERSION): cv.string,
-            vol.Required(ATTR_SUPPORTS_ENCRYPTION, default=False): cv.boolean,
-        }
+        vol.Schema(
+            {
+                vol.Optional(ATTR_APP_DATA, default={}): dict,
+                vol.Required(ATTR_APP_ID): cv.string,
+                vol.Required(ATTR_APP_NAME): cv.string,
+                vol.Required(ATTR_APP_VERSION): cv.string,
+                vol.Required(ATTR_DEVICE_NAME): cv.string,
+                vol.Required(ATTR_MANUFACTURER): cv.string,
+                vol.Required(ATTR_MODEL): cv.string,
+                vol.Optional(ATTR_MODEL_ID): cv.string,  # Added in 0.104
+                vol.Required(ATTR_OS_NAME): cv.string,
+                vol.Optional(ATTR_OS_VERSION): cv.string,
+                vol.Required(ATTR_SUPPORTS_ENCRYPTION, default=False): cv.boolean,
+            },
+            # To allow future apps to send more data
+            extra=vol.REMOVE_EXTRA,
+        )
     )
     async def post(self, request: Request, data: Dict) -> Response:
         """Handle the POST request for registration."""
@@ -64,7 +70,13 @@ class RegistrationsView(HomeAssistantView):
                 CONF_CLOUDHOOK_URL
             ] = await hass.components.cloud.async_create_cloudhook(webhook_id)
 
-        data[ATTR_DEVICE_ID] = str(uuid.uuid4()).replace("-", "")
+        model_id = data.get(ATTR_MODEL_ID)
+
+        if model_id is None:
+            data[ATTR_DEVICE_ID] = str(uuid.uuid4()).replace("-", "")
+
+        else:
+            data[ATTR_DEVICE_ID] = f"{data[ATTR_APP_ID]}-{model_id}"
 
         data[CONF_WEBHOOK_ID] = webhook_id
 
@@ -73,9 +85,10 @@ class RegistrationsView(HomeAssistantView):
 
         data[CONF_USER_ID] = request["hass_user"].id
 
-        ctx = {"source": "registration"}
         await hass.async_create_task(
-            hass.config_entries.flow.async_init(DOMAIN, context=ctx, data=data)
+            hass.config_entries.flow.async_init(
+                DOMAIN, data=data, context={"source": "registration"}
+            )
         )
 
         remote_ui_url = None
diff --git a/tests/components/mobile_app/const.py b/tests/components/mobile_app/const.py
index 1570406d8d5..f065f19f675 100644
--- a/tests/components/mobile_app/const.py
+++ b/tests/components/mobile_app/const.py
@@ -17,6 +17,7 @@ REGISTER = {
     "device_name": "Test 1",
     "manufacturer": "mobile_app",
     "model": "Test",
+    "model_id": "mock-model-id",
     "os_name": "Linux",
     "os_version": "1.0",
     "supports_encryption": True,
diff --git a/tests/components/mobile_app/test_http_api.py b/tests/components/mobile_app/test_http_api.py
index 158d3ffe213..491ea73223c 100644
--- a/tests/components/mobile_app/test_http_api.py
+++ b/tests/components/mobile_app/test_http_api.py
@@ -33,6 +33,7 @@ async def test_registration(hass, hass_client):
 
     entries = hass.config_entries.async_entries(DOMAIN)
 
+    assert entries[0].unique_id == "io.homeassistant.mobile_app_test-mock-model-id"
     assert entries[0].data["app_data"] == REGISTER["app_data"]
     assert entries[0].data["app_id"] == REGISTER["app_id"]
     assert entries[0].data["app_name"] == REGISTER["app_name"]