diff --git a/homeassistant/components/lyngdorf/config_flow.py b/homeassistant/components/lyngdorf/config_flow.py
index f06633f16cdd..94366cc67b62 100644
--- a/homeassistant/components/lyngdorf/config_flow.py
+++ b/homeassistant/components/lyngdorf/config_flow.py
@@ -4,6 +4,7 @@ import logging
 from typing import Any, override
 from urllib.parse import urlparse
 
+from lyngdorf.const import LyngdorfModel
 from lyngdorf.device import (
     async_find_receiver_model,
     async_get_device_serial,
@@ -54,31 +55,26 @@ class LyngdorfFlowHandler(ConfigFlow, domain=DOMAIN):
 
         if user_input is not None:
             self._host = user_input[CONF_HOST]
-
             try:
-                model = await async_find_receiver_model(self._host)
-            except TimeoutError:
+                model, serial = await self._async_probe(self._host)
+            except TimeoutConnect:
                 errors["base"] = "timeout_connect"
-            except OSError:
+            except CannotConnect:
                 errors["base"] = "cannot_connect"
-            except Exception:  # noqa: BLE001
-                errors["base"] = "unknown"
-
-            if not errors and not model:
+            except UnsupportedModel:
                 errors["base"] = "unsupported_model"
-
-            if not errors and model:
+            except CannotDetermineId:
+                errors["base"] = "cannot_determine_id"
+            except Exception:
+                _LOGGER.exception("Unexpected exception")
+                errors["base"] = "unknown"
+            else:
                 self._device_model = model.model_name
                 self._name = model.model_name
-
-                serial = await async_get_device_serial(self._host)
-                if not serial:
-                    errors["base"] = "cannot_determine_id"
-                else:
-                    self._device_serial_number = serial.lower()
-                    await self.async_set_unique_id(self._device_serial_number)
-                    self._abort_if_unique_id_configured()
-                    return await self._create_entry()
+                self._device_serial_number = serial
+                await self.async_set_unique_id(serial)
+                self._abort_if_unique_id_configured()
+                return await self._create_entry()
 
         return self.async_show_form(
             step_id="user",
@@ -90,6 +86,76 @@ class LyngdorfFlowHandler(ConfigFlow, domain=DOMAIN):
             errors=errors,
         )
 
+    async def _async_probe(self, host: str) -> tuple[LyngdorfModel, str]:
+        """Return the model and serial of the device at a host."""
+        try:
+            model = await async_find_receiver_model(host)
+        except TimeoutError as err:
+            raise TimeoutConnect from err
+        except OSError as err:
+            raise CannotConnect from err
+        if not model:
+            raise UnsupportedModel
+
+        try:
+            serial = await async_get_device_serial(host)
+        except TimeoutError as err:
+            raise TimeoutConnect from err
+        except OSError as err:
+            raise CannotConnect from err
+        if not serial:
+            raise CannotDetermineId
+
+        return model, serial.lower()
+
+    async def async_step_reconfigure(
+        self, user_input: dict[str, Any] | None = None
+    ) -> ConfigFlowResult:
+        """Handle reconfiguration of an existing entry.
+
+        SSDP rediscovery only recovers a changed address while the device is
+        still announcing somewhere Home Assistant can hear it, which a move to
+        a static address or another subnet can end.
+        """
+        errors: dict[str, str] = {}
+        reconfigure_entry = self._get_reconfigure_entry()
+
+        if user_input is not None:
+            host = user_input[CONF_HOST]
+            try:
+                model, serial = await self._async_probe(host)
+            except TimeoutConnect:
+                errors["base"] = "timeout_connect"
+            except CannotConnect:
+                errors["base"] = "cannot_connect"
+            except UnsupportedModel:
+                errors["base"] = "unsupported_model"
+            except CannotDetermineId:
+                errors["base"] = "cannot_determine_id"
+            except Exception:
+                _LOGGER.exception("Unexpected exception")
+                errors["base"] = "unknown"
+            else:
+                await self.async_set_unique_id(serial)
+                self._abort_if_unique_id_mismatch()
+                return self.async_update_reload_and_abort(
+                    reconfigure_entry,
+                    data_updates={
+                        CONF_HOST: host,
+                        CONF_MODEL: model.model_name,
+                        CONF_SERIAL_NUMBER: serial,
+                    },
+                )
+
+        return self.async_show_form(
+            step_id="reconfigure",
+            data_schema=self.add_suggested_values_to_schema(
+                vol.Schema({vol.Required(CONF_HOST): cv.string}),
+                reconfigure_entry.data,
+            ),
+            errors=errors,
+        )
+
     @override
     async def async_step_ssdp(
         self, discovery_info: SsdpServiceInfo
@@ -181,3 +247,19 @@ class LyngdorfFlowHandler(ConfigFlow, domain=DOMAIN):
             raise AbortFlow("cannot_determine_id")
         await self.async_set_unique_id(self._device_serial_number)
         self._abort_if_unique_id_configured(updates={CONF_HOST: self._host})
+
+
+class CannotConnect(Exception):
+    """Error to indicate we cannot connect."""
+
+
+class TimeoutConnect(Exception):
+    """Error to indicate the device did not answer in time."""
+
+
+class UnsupportedModel(Exception):
+    """Error to indicate the device is not a model we support."""
+
+
+class CannotDetermineId(Exception):
+    """Error to indicate the device did not report a serial."""
diff --git a/homeassistant/components/lyngdorf/quality_scale.yaml b/homeassistant/components/lyngdorf/quality_scale.yaml
index 2974ff508323..c20a592b33a6 100644
--- a/homeassistant/components/lyngdorf/quality_scale.yaml
+++ b/homeassistant/components/lyngdorf/quality_scale.yaml
@@ -74,7 +74,7 @@ rules:
   entity-translations: done
   exception-translations: done
   icon-translations: done
-  reconfiguration-flow: todo
+  reconfiguration-flow: done
   repair-issues:
     status: exempt
     comment: No repair issues needed.
diff --git a/homeassistant/components/lyngdorf/strings.json b/homeassistant/components/lyngdorf/strings.json
index f28652c7fe23..4b3baf44bc6a 100644
--- a/homeassistant/components/lyngdorf/strings.json
+++ b/homeassistant/components/lyngdorf/strings.json
@@ -5,6 +5,8 @@
       "already_in_progress": "[%key:common::config_flow::abort::already_in_progress%]",
       "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]",
       "cannot_determine_id": "[%key:component::lyngdorf::config::error::cannot_determine_id%]",
+      "reconfigure_successful": "[%key:common::config_flow::abort::reconfigure_successful%]",
+      "unique_id_mismatch": "The device at this address is a different Lyngdorf device from the one this entry was set up with.",
       "unsupported_model": "This Lyngdorf model is not supported"
     },
     "error": {
@@ -19,6 +21,16 @@
       "confirm": {
         "description": "Do you want to set up **{name}**?"
       },
+      "reconfigure": {
+        "data": {
+          "host": "[%key:common::config_flow::data::host%]"
+        },
+        "data_description": {
+          "host": "[%key:component::lyngdorf::config::step::user::data_description::host%]"
+        },
+        "description": "Update the address Home Assistant uses to reach this device. It must be the same device; a different one will be rejected.",
+        "title": "[%key:component::lyngdorf::config::step::user::title%]"
+      },
       "user": {
         "data": {
           "host": "[%key:common::config_flow::data::host%]"
diff --git a/tests/components/lyngdorf/test_config_flow.py b/tests/components/lyngdorf/test_config_flow.py
index ac001aa7d6e6..7dabfb3a8ea4 100644
--- a/tests/components/lyngdorf/test_config_flow.py
+++ b/tests/components/lyngdorf/test_config_flow.py
@@ -368,3 +368,162 @@ async def test_ssdp_discovery_connectivity_check_aborts(
 
     assert result["type"] is FlowResultType.ABORT
     assert result["reason"] == expected_reason
+
+
+@pytest.mark.usefixtures("mock_find_receiver_model", "mock_get_device_serial")
+async def test_reconfigure(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Test reconfiguring an entry updates the host."""
+    mock_config_entry.add_to_hass(hass)
+
+    result = await mock_config_entry.start_reconfigure_flow(hass)
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "reconfigure"
+
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {CONF_HOST: "192.168.1.50"},
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "reconfigure_successful"
+    assert mock_config_entry.data[CONF_HOST] == "192.168.1.50"
+
+
+@pytest.mark.usefixtures("mock_find_receiver_model")
+async def test_reconfigure_different_device(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_get_device_serial: AsyncMock,
+) -> None:
+    """Test an entry cannot be pointed at a different device."""
+    mock_config_entry.add_to_hass(hass)
+    mock_get_device_serial.return_value = "aabbccddeeff"
+    original_host = mock_config_entry.data[CONF_HOST]
+
+    result = await mock_config_entry.start_reconfigure_flow(hass)
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {CONF_HOST: "192.168.1.50"},
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "unique_id_mismatch"
+    assert mock_config_entry.data[CONF_HOST] == original_host
+
+
+@pytest.mark.parametrize(
+    ("side_effect", "error"),
+    [
+        (TimeoutError, "timeout_connect"),
+        (OSError, "cannot_connect"),
+        (Exception, "unknown"),
+    ],
+)
+@pytest.mark.usefixtures("mock_get_device_serial")
+async def test_reconfigure_errors(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_find_receiver_model: AsyncMock,
+    side_effect: type[Exception],
+    error: str,
+) -> None:
+    """Test reconfigure surfaces connection errors and recovers."""
+    mock_config_entry.add_to_hass(hass)
+    mock_find_receiver_model.side_effect = side_effect
+
+    result = await mock_config_entry.start_reconfigure_flow(hass)
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {CONF_HOST: "192.168.1.50"},
+    )
+
+    assert result["type"] is FlowResultType.FORM
+    assert result["errors"] == {"base": error}
+
+    mock_find_receiver_model.side_effect = None
+    mock_find_receiver_model.return_value = LyngdorfModel.MP_60
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        {CONF_HOST: "192.168.1.50"},
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "reconfigure_successful"
+
+
+@pytest.mark.parametrize(
+    ("side_effect", "error"),
+    [
+        (TimeoutError, "timeout_connect"),
+        (OSError, "cannot_connect"),
+    ],
+)
+@pytest.mark.usefixtures("mock_find_receiver_model")
+async def test_user_flow_serial_errors(
+    hass: HomeAssistant,
+    mock_get_device_serial: AsyncMock,
+    side_effect: type[Exception],
+    error: str,
+) -> None:
+    """Test a failure to read the serial is surfaced on the form."""
+    mock_get_device_serial.side_effect = side_effect
+
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": SOURCE_USER}
+    )
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"], {CONF_HOST: "192.168.1.50"}
+    )
+
+    assert result["type"] is FlowResultType.FORM
+    assert result["errors"] == {"base": error}
+
+    mock_get_device_serial.side_effect = None
+    mock_get_device_serial.return_value = "0050c27c76b2"
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"], {CONF_HOST: "192.168.1.50"}
+    )
+
+    assert result["type"] is FlowResultType.CREATE_ENTRY
+
+
+@pytest.mark.parametrize(
+    ("model", "serial", "error"),
+    [
+        pytest.param(None, "0050c27c76b2", "unsupported_model", id="unsupported"),
+        pytest.param(LyngdorfModel.MP_60, None, "cannot_determine_id", id="no_serial"),
+    ],
+)
+async def test_reconfigure_device_errors(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_find_receiver_model: AsyncMock,
+    mock_get_device_serial: AsyncMock,
+    model: LyngdorfModel | None,
+    serial: str | None,
+    error: str,
+) -> None:
+    """Test reconfigure surfaces a device it cannot identify."""
+    mock_config_entry.add_to_hass(hass)
+    mock_find_receiver_model.return_value = model
+    mock_get_device_serial.return_value = serial
+
+    result = await mock_config_entry.start_reconfigure_flow(hass)
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"], {CONF_HOST: "192.168.1.50"}
+    )
+
+    assert result["type"] is FlowResultType.FORM
+    assert result["errors"] == {"base": error}
+
+    mock_find_receiver_model.return_value = LyngdorfModel.MP_60
+    mock_get_device_serial.return_value = "0050c27c76b2"
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"], {CONF_HOST: "192.168.1.50"}
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "reconfigure_successful"