diff --git a/homeassistant/components/upcloud/config_flow.py b/homeassistant/components/upcloud/config_flow.py
index e6868be29b9..fda6c1d561b 100644
--- a/homeassistant/components/upcloud/config_flow.py
+++ b/homeassistant/components/upcloud/config_flow.py
@@ -55,6 +55,9 @@ class UpCloudConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
                 step_id="user", user_input=user_input, errors=errors
             )
 
+        self._abort_if_unique_id_configured(
+            updates={CONF_PASSWORD: user_input[CONF_PASSWORD]}
+        )
         return self.async_create_entry(title=user_input[CONF_USERNAME], data=user_input)
 
     @callback
diff --git a/homeassistant/components/upcloud/strings.json b/homeassistant/components/upcloud/strings.json
index 3daf70be598..fc52916e9b4 100644
--- a/homeassistant/components/upcloud/strings.json
+++ b/homeassistant/components/upcloud/strings.json
@@ -11,6 +11,9 @@
           "password": "[%key:common::config_flow::data::password%]"
         }
       }
+    },
+    "abort": {
+      "already_configured": "[%key:common::config_flow::abort::already_configured_service%]"
     }
   },
   "options": {
diff --git a/tests/components/upcloud/test_config_flow.py b/tests/components/upcloud/test_config_flow.py
index 5a52bb62c27..eadbe1c8fe6 100644
--- a/tests/components/upcloud/test_config_flow.py
+++ b/tests/components/upcloud/test_config_flow.py
@@ -72,7 +72,8 @@ async def test_success(
     hass: HomeAssistant, requests_mock: requests_mock.Mocker
 ) -> None:
     """Test successful flow provides entry creation data."""
-    requests_mock.request(ANY, ANY, text='{"account":{"username":"user"}}')
+    requests_mock.request(ANY, "/1.3/account", text='{"account":{"username":"user"}}')
+    requests_mock.request(ANY, "/1.3/server", text='{"servers": {"server":[]}}')
     result = await hass.config_entries.flow.async_init(
         DOMAIN, context={"source": config_entries.SOURCE_USER}, data=FIXTURE_USER_INPUT
     )
@@ -105,3 +106,28 @@ async def test_options(hass: HomeAssistant) -> None:
     assert result["data"][CONF_SCAN_INTERVAL] == int(
         FIXTURE_USER_INPUT_OPTIONS[CONF_SCAN_INTERVAL]
     )
+
+
+async def test_already_configured(hass, requests_mock):
+    """Test duplicate entry aborts and updates data."""
+
+    config_entry = MockConfigEntry(
+        domain=DOMAIN,
+        unique_id=FIXTURE_USER_INPUT[CONF_USERNAME],
+        data=FIXTURE_USER_INPUT,
+        options=FIXTURE_USER_INPUT_OPTIONS,
+    )
+    config_entry.add_to_hass(hass)
+
+    new_user_input = FIXTURE_USER_INPUT.copy()
+    new_user_input[CONF_PASSWORD] += "_changed"
+
+    requests_mock.request(ANY, "/1.3/account", text='{"account":{"username":"user"}}')
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": config_entries.SOURCE_USER}, data=new_user_input
+    )
+
+    assert result["type"] == data_entry_flow.RESULT_TYPE_ABORT
+    assert result["reason"] == "already_configured"
+    assert config_entry.data[CONF_USERNAME] == new_user_input[CONF_USERNAME]
+    assert config_entry.data[CONF_PASSWORD] == new_user_input[CONF_PASSWORD]