diff --git a/homeassistant/components/reolink/update.py b/homeassistant/components/reolink/update.py
index 9b710c6576d..3c1e70612a7 100644
--- a/homeassistant/components/reolink/update.py
+++ b/homeassistant/components/reolink/update.py
@@ -137,8 +137,7 @@ class ReolinkUpdateEntity(
     async def async_release_notes(self) -> str | None:
         """Return the release notes."""
         new_firmware = self._host.api.firmware_update_available(self._channel)
-        if not isinstance(new_firmware, NewSoftwareVersion):
-            return None
+        assert isinstance(new_firmware, NewSoftwareVersion)
 
         return (
             "If the install button fails, download this"
@@ -229,8 +228,7 @@ class ReolinkHostUpdateEntity(
     async def async_release_notes(self) -> str | None:
         """Return the release notes."""
         new_firmware = self._host.api.firmware_update_available()
-        if not isinstance(new_firmware, NewSoftwareVersion):
-            return None
+        assert isinstance(new_firmware, NewSoftwareVersion)
 
         return (
             "If the install button fails, download this"
diff --git a/tests/components/reolink/conftest.py b/tests/components/reolink/conftest.py
index be87aac9291..b0f599c28fb 100644
--- a/tests/components/reolink/conftest.py
+++ b/tests/components/reolink/conftest.py
@@ -35,6 +35,7 @@ TEST_PORT = 1234
 TEST_NVR_NAME = "test_reolink_name"
 TEST_CAM_NAME = "test_reolink_cam"
 TEST_NVR_NAME2 = "test2_reolink_name"
+TEST_CAM_NAME = "test_reolink_cam"
 TEST_USE_HTTPS = True
 TEST_HOST_MODEL = "RLN8-410"
 TEST_ITEM_NUMBER = "P000"
diff --git a/tests/components/reolink/test_update.py b/tests/components/reolink/test_update.py
new file mode 100644
index 00000000000..3ad10a11499
--- /dev/null
+++ b/tests/components/reolink/test_update.py
@@ -0,0 +1,131 @@
+"""Test the Reolink update platform."""
+
+from unittest.mock import MagicMock, patch
+
+from freezegun.api import FrozenDateTimeFactory
+import pytest
+from reolink_aio.exceptions import ReolinkError
+from reolink_aio.software_version import NewSoftwareVersion
+
+from homeassistant.components.reolink.update import POLL_AFTER_INSTALL
+from homeassistant.components.update import DOMAIN as UPDATE_DOMAIN, SERVICE_INSTALL
+from homeassistant.config_entries import ConfigEntryState
+from homeassistant.const import ATTR_ENTITY_ID, STATE_OFF, STATE_ON, Platform
+from homeassistant.core import HomeAssistant
+from homeassistant.exceptions import HomeAssistantError
+
+from .conftest import TEST_CAM_NAME, TEST_NVR_NAME
+
+from tests.common import MockConfigEntry, async_fire_time_changed
+from tests.typing import WebSocketGenerator
+
+TEST_DOWNLOAD_URL = "https://reolink.com/test"
+TEST_RELEASE_NOTES = "bugfix 1, bugfix 2"
+
+
+@pytest.mark.parametrize("entity_name", [TEST_NVR_NAME, TEST_CAM_NAME])
+async def test_no_update(
+    hass: HomeAssistant,
+    config_entry: MockConfigEntry,
+    reolink_connect: MagicMock,
+    entity_name: str,
+) -> None:
+    """Test update state when no update available."""
+    reolink_connect.camera_name.return_value = TEST_CAM_NAME
+
+    with patch("homeassistant.components.reolink.PLATFORMS", [Platform.UPDATE]):
+        assert await hass.config_entries.async_setup(config_entry.entry_id)
+    await hass.async_block_till_done()
+    assert config_entry.state is ConfigEntryState.LOADED
+
+    entity_id = f"{Platform.UPDATE}.{entity_name}_firmware"
+    assert hass.states.get(entity_id).state == STATE_OFF
+
+
+@pytest.mark.parametrize("entity_name", [TEST_NVR_NAME, TEST_CAM_NAME])
+async def test_update_str(
+    hass: HomeAssistant,
+    config_entry: MockConfigEntry,
+    reolink_connect: MagicMock,
+    entity_name: str,
+) -> None:
+    """Test update state when update available with string from API."""
+    reolink_connect.camera_name.return_value = TEST_CAM_NAME
+    reolink_connect.firmware_update_available.return_value = "New firmware available"
+
+    with patch("homeassistant.components.reolink.PLATFORMS", [Platform.UPDATE]):
+        assert await hass.config_entries.async_setup(config_entry.entry_id)
+    await hass.async_block_till_done()
+    assert config_entry.state is ConfigEntryState.LOADED
+
+    entity_id = f"{Platform.UPDATE}.{entity_name}_firmware"
+    assert hass.states.get(entity_id).state == STATE_ON
+
+
+@pytest.mark.parametrize("entity_name", [TEST_NVR_NAME, TEST_CAM_NAME])
+async def test_update_firm(
+    hass: HomeAssistant,
+    config_entry: MockConfigEntry,
+    reolink_connect: MagicMock,
+    hass_ws_client: WebSocketGenerator,
+    freezer: FrozenDateTimeFactory,
+    entity_name: str,
+) -> None:
+    """Test update state when update available with firmware info from reolink.com."""
+    reolink_connect.camera_name.return_value = TEST_CAM_NAME
+    new_firmware = NewSoftwareVersion(
+        version_string="v3.3.0.226_23031644",
+        download_url=TEST_DOWNLOAD_URL,
+        release_notes=TEST_RELEASE_NOTES,
+    )
+    reolink_connect.firmware_update_available.return_value = new_firmware
+
+    with patch("homeassistant.components.reolink.PLATFORMS", [Platform.UPDATE]):
+        assert await hass.config_entries.async_setup(config_entry.entry_id)
+    await hass.async_block_till_done()
+    assert config_entry.state is ConfigEntryState.LOADED
+
+    entity_id = f"{Platform.UPDATE}.{entity_name}_firmware"
+    assert hass.states.get(entity_id).state == STATE_ON
+
+    # release notes
+    client = await hass_ws_client(hass)
+    await hass.async_block_till_done()
+
+    await client.send_json(
+        {
+            "id": 1,
+            "type": "update/release_notes",
+            "entity_id": entity_id,
+        }
+    )
+    result = await client.receive_json()
+    assert TEST_DOWNLOAD_URL in result["result"]
+    assert TEST_RELEASE_NOTES in result["result"]
+
+    # test install
+    await hass.services.async_call(
+        UPDATE_DOMAIN,
+        SERVICE_INSTALL,
+        {ATTR_ENTITY_ID: entity_id},
+        blocking=True,
+    )
+    reolink_connect.update_firmware.assert_called()
+
+    reolink_connect.update_firmware.side_effect = ReolinkError("Test error")
+    with pytest.raises(HomeAssistantError):
+        await hass.services.async_call(
+            UPDATE_DOMAIN,
+            SERVICE_INSTALL,
+            {ATTR_ENTITY_ID: entity_id},
+            blocking=True,
+        )
+
+    # test _async_update_future
+    reolink_connect.camera_sw_version.return_value = "v3.3.0.226_23031644"
+    reolink_connect.firmware_update_available.return_value = False
+    freezer.tick(POLL_AFTER_INSTALL)
+    async_fire_time_changed(hass)
+    await hass.async_block_till_done()
+
+    assert hass.states.get(entity_id).state == STATE_OFF