diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6c8e4cd..27cca0c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## Next version
+
+### ✨ Improved
+
+* Added `NPSClient.all_off()` to turn off all outlets at once.
+
+
 ## 1.0.0 - November 24, 2023
 
 ### 🔥 Breaking changes
diff --git a/src/lvmnps/nps/core.py b/src/lvmnps/nps/core.py
index 3e72441..1f98d11 100644
--- a/src/lvmnps/nps/core.py
+++ b/src/lvmnps/nps/core.py
@@ -195,6 +195,13 @@ async def _set_state_internal(
 
         """
 
+        pass
+
+    async def all_off(self):
+        """Turns off all outlets."""
+
+        await self._set_state_internal(list(self.outlets.values()), on=False)
+
     async def cycle(
         self,
         outlets: OutletArgType,
diff --git a/tests/test_nps.py b/tests/test_nps.py
index 0a5b1ec..8c62b94 100644
--- a/tests/test_nps.py
+++ b/tests/test_nps.py
@@ -9,6 +9,7 @@
 from __future__ import annotations
 
 import pytest
+from pytest_mock import MockerFixture
 
 from lvmnps.nps.core import NPSClient, OutletModel
 
@@ -79,3 +80,14 @@ async def test_client_get(nps_test_client: NPSClient, outlet: str | int):
 async def test_client_get_invalid_type(nps_test_client: NPSClient):
     with pytest.raises(TypeError):
         nps_test_client.get(None)  # type: ignore
+
+
+async def test_all_off(nps_test_client: NPSClient, mocker: MockerFixture):
+    assert nps_test_client is not None
+
+    nps_test_client._set_state_internal = mocker.AsyncMock()
+
+    await nps_test_client.all_off()
+
+    outlets = list(nps_test_client.outlets.values())
+    nps_test_client._set_state_internal.assert_called_once_with(outlets, on=False)