diff --git a/homeassistant/components/tado/config_flow.py b/homeassistant/components/tado/config_flow.py
index c14b4284cf3..fb60b820ab9 100644
--- a/homeassistant/components/tado/config_flow.py
+++ b/homeassistant/components/tado/config_flow.py
@@ -92,6 +92,10 @@ class ConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
             # they already have one configured as they can always
             # add a new one via "+"
             return self.async_abort(reason="already_configured")
+        properties = {
+            key.lower(): value for (key, value) in homekit_info["properties"].items()
+        }
+        await self.async_set_unique_id(properties["id"])
         return await self.async_step_user()
 
     async def async_step_import(self, user_input):
diff --git a/tests/components/tado/test_config_flow.py b/tests/components/tado/test_config_flow.py
index fb9156d96d9..0c75eadfb0e 100644
--- a/tests/components/tado/test_config_flow.py
+++ b/tests/components/tado/test_config_flow.py
@@ -151,10 +151,18 @@ async def test_form_homekit(hass):
     await setup.async_setup_component(hass, "persistent_notification", {})
 
     result = await hass.config_entries.flow.async_init(
-        DOMAIN, context={"source": "homekit"}
+        DOMAIN,
+        context={"source": "homekit"},
+        data={"properties": {"id": "AA:BB:CC:DD:EE:FF"}},
     )
     assert result["type"] == "form"
     assert result["errors"] == {}
+    flow = next(
+        flow
+        for flow in hass.config_entries.flow.async_progress()
+        if flow["flow_id"] == result["flow_id"]
+    )
+    assert flow["context"]["unique_id"] == "AA:BB:CC:DD:EE:FF"
 
     entry = MockConfigEntry(
         domain=DOMAIN, data={CONF_USERNAME: "mock", CONF_PASSWORD: "mock"}
@@ -162,6 +170,8 @@ async def test_form_homekit(hass):
     entry.add_to_hass(hass)
 
     result = await hass.config_entries.flow.async_init(
-        DOMAIN, context={"source": "homekit"}
+        DOMAIN,
+        context={"source": "homekit"},
+        data={"properties": {"id": "AA:BB:CC:DD:EE:FF"}},
     )
     assert result["type"] == "abort"