diff --git a/homeassistant/components/maxcube/binary_sensor.py b/homeassistant/components/maxcube/binary_sensor.py
index 223c0e3fc99..999d7af01c5 100644
--- a/homeassistant/components/maxcube/binary_sensor.py
+++ b/homeassistant/components/maxcube/binary_sensor.py
@@ -35,6 +35,11 @@ class MaxCubeShutter(BinarySensorEntity):
         """Return the name of the BinarySensorEntity."""
         return self._name
 
+    @property
+    def unique_id(self):
+        """Return a unique ID."""
+        return self._device.serial
+
     @property
     def device_class(self):
         """Return the class of this sensor."""
diff --git a/homeassistant/components/maxcube/climate.py b/homeassistant/components/maxcube/climate.py
index 75ee7ef21f0..175f44b9d0e 100644
--- a/homeassistant/components/maxcube/climate.py
+++ b/homeassistant/components/maxcube/climate.py
@@ -87,6 +87,11 @@ class MaxCubeClimate(ClimateEntity):
         """Return the name of the climate device."""
         return self._name
 
+    @property
+    def unique_id(self):
+        """Return a unique ID."""
+        return self._device.serial
+
     @property
     def min_temp(self):
         """Return the minimum temperature."""
diff --git a/tests/components/maxcube/test_maxcube_binary_sensor.py b/tests/components/maxcube/test_maxcube_binary_sensor.py
index db5228c5c9a..48d34a0df4e 100644
--- a/tests/components/maxcube/test_maxcube_binary_sensor.py
+++ b/tests/components/maxcube/test_maxcube_binary_sensor.py
@@ -11,6 +11,7 @@ from homeassistant.const import (
     STATE_OFF,
     STATE_ON,
 )
+from homeassistant.helpers import entity_registry as er
 from homeassistant.util import utcnow
 
 from tests.common import async_fire_time_changed
@@ -20,6 +21,11 @@ ENTITY_ID = "binary_sensor.testroom_testshutter"
 
 async def test_window_shuttler(hass, cube: MaxCube, windowshutter: MaxWindowShutter):
     """Test a successful setup with a shuttler device."""
+    entity_registry = er.async_get(hass)
+    assert entity_registry.async_is_registered(ENTITY_ID)
+    entity = entity_registry.async_get(ENTITY_ID)
+    assert entity.unique_id == "AABBCCDD03"
+
     state = hass.states.get(ENTITY_ID)
     assert state is not None
     assert state.state == STATE_ON
diff --git a/tests/components/maxcube/test_maxcube_climate.py b/tests/components/maxcube/test_maxcube_climate.py
index b59e1372fde..b234bbd130c 100644
--- a/tests/components/maxcube/test_maxcube_climate.py
+++ b/tests/components/maxcube/test_maxcube_climate.py
@@ -54,6 +54,7 @@ from homeassistant.const import (
     ATTR_SUPPORTED_FEATURES,
     ATTR_TEMPERATURE,
 )
+from homeassistant.helpers import entity_registry as er
 from homeassistant.util import utcnow
 
 from tests.common import async_fire_time_changed
@@ -65,6 +66,10 @@ VALVE_POSITION = "valve_position"
 
 async def test_setup_thermostat(hass, cube: MaxCube):
     """Test a successful setup of a thermostat device."""
+    entity_registry = er.async_get(hass)
+    assert entity_registry.async_is_registered(ENTITY_ID)
+    entity = entity_registry.async_get(ENTITY_ID)
+    assert entity.unique_id == "AABBCCDD01"
 
     state = hass.states.get(ENTITY_ID)
     assert state.state == HVAC_MODE_AUTO
@@ -94,6 +99,11 @@ async def test_setup_thermostat(hass, cube: MaxCube):
 
 async def test_setup_wallthermostat(hass, cube: MaxCube):
     """Test a successful setup of a wall thermostat device."""
+    entity_registry = er.async_get(hass)
+    assert entity_registry.async_is_registered(WALL_ENTITY_ID)
+    entity = entity_registry.async_get(WALL_ENTITY_ID)
+    assert entity.unique_id == "AABBCCDD02"
+
     state = hass.states.get(WALL_ENTITY_ID)
     assert state.state == HVAC_MODE_OFF
     assert state.attributes.get(ATTR_FRIENDLY_NAME) == "TestRoom TestWallThermostat"