diff --git a/homeassistant/components/axle_energy/config_flow.py b/homeassistant/components/axle_energy/config_flow.py
index c547be556541..d8c237b40405 100644
--- a/homeassistant/components/axle_energy/config_flow.py
+++ b/homeassistant/components/axle_energy/config_flow.py
@@ -1,5 +1,6 @@
 """Config flow for Axle Energy."""
 
+from collections.abc import Mapping
 from typing import Any, override
 
 from aioaxlevpp import (
@@ -12,6 +13,7 @@ import probatio
 
 from homeassistant.config_entries import ConfigFlow, ConfigFlowResult
 from homeassistant.const import CONF_API_KEY
+from homeassistant.data_entry_flow import AbortFlow
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
 from homeassistant.helpers.selector import (
     TextSelector,
@@ -66,3 +68,35 @@ class AxleConfigFlow(ConfigFlow, domain=DOMAIN):
             },
             errors=errors,
         )
+
+    async def async_step_reauth(
+        self, entry_data: Mapping[str, Any]
+    ) -> ConfigFlowResult:
+        """Handle an API key that is no longer accepted."""
+        return await self.async_step_reauth_confirm()
+
+    async def async_step_reauth_confirm(
+        self, user_input: dict[str, Any] | None = None
+    ) -> ConfigFlowResult:
+        """Validate a replacement API key and reload the existing feed."""
+        errors = {}
+        if user_input is not None:
+            try:
+                self._async_abort_entries_match(
+                    {CONF_API_KEY: user_input[CONF_API_KEY]}
+                )
+            except AbortFlow:
+                errors[CONF_API_KEY] = "already_configured"
+            else:
+                if not (errors := await self._validate(user_input)):
+                    return self.async_update_reload_and_abort(
+                        self._get_reauth_entry(), data_updates=user_input
+                    )
+        return self.async_show_form(
+            step_id="reauth_confirm",
+            data_schema=STEP_SCHEMA,
+            description_placeholders={
+                "token_url": "https://vpp.axle.energy/app/account/home-assistant"
+            },
+            errors=errors,
+        )
diff --git a/homeassistant/components/axle_energy/quality_scale.yaml b/homeassistant/components/axle_energy/quality_scale.yaml
index d6a494436373..07103f66e980 100644
--- a/homeassistant/components/axle_energy/quality_scale.yaml
+++ b/homeassistant/components/axle_energy/quality_scale.yaml
@@ -39,7 +39,7 @@ rules:
   integration-owner: done
   log-when-unavailable: done
   parallel-updates: done
-  reauthentication-flow: todo
+  reauthentication-flow: done
   test-coverage: done
   devices: done
   diagnostics: todo
diff --git a/homeassistant/components/axle_energy/strings.json b/homeassistant/components/axle_energy/strings.json
index 468bff368d30..518b87c3e0de 100644
--- a/homeassistant/components/axle_energy/strings.json
+++ b/homeassistant/components/axle_energy/strings.json
@@ -4,11 +4,21 @@
       "already_configured": "[%key:common::config_flow::abort::already_configured_service%]"
     },
     "error": {
+      "already_configured": "This API key is already used by another entry.",
       "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]",
       "cannot_retrieve": "[%key:component::axle_energy::exceptions::cannot_connect::message%]",
       "invalid_auth": "[%key:common::config_flow::error::invalid_auth%]"
     },
     "step": {
+      "reauth_confirm": {
+        "data": {
+          "api_key": "[%key:common::config_flow::data::api_key%]"
+        },
+        "data_description": {
+          "api_key": "[%key:component::axle_energy::config::step::user::data_description::api_key%]"
+        },
+        "description": "Your Axle API key is no longer accepted. Open the [Home Assistant page in your Axle account]({token_url}) and copy your Home Assistant token. If **Generate Token** is available, select it first. Enter the token in **API key**. If the token is still rejected, contact Axle support."
+      },
       "user": {
         "data": {
           "api_key": "[%key:common::config_flow::data::api_key%]"
diff --git a/tests/components/axle_energy/test_config_flow.py b/tests/components/axle_energy/test_config_flow.py
index aad671f8372d..c3bfa680b36d 100644
--- a/tests/components/axle_energy/test_config_flow.py
+++ b/tests/components/axle_energy/test_config_flow.py
@@ -6,10 +6,11 @@ from aioaxlevpp import AxleAuthenticationError, AxleConnectionError, AxleError
 import pytest
 
 from homeassistant.components.axle_energy.const import DOMAIN
-from homeassistant.config_entries import SOURCE_USER
+from homeassistant.config_entries import SOURCE_USER, ConfigEntryState
 from homeassistant.const import CONF_API_KEY
 from homeassistant.core import HomeAssistant
 from homeassistant.data_entry_flow import FlowResultType
+from homeassistant.setup import async_setup_component
 
 from tests.common import MockConfigEntry
 
@@ -78,3 +79,118 @@ async def test_duplicate(
     assert result["type"] is FlowResultType.ABORT
     assert result["reason"] == "already_configured"
     mock_client.get_event.assert_not_called()
+
+
+@pytest.mark.parametrize("api_key", ["replacement-token", "test-token"])
+async def test_reauth(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_client: AsyncMock,
+    mock_setup_entry: AsyncMock,
+    api_key: str,
+) -> None:
+    """Reauthenticate the existing feed, including when no event is scheduled."""
+    mock_client.get_event.return_value = None
+    mock_config_entry.add_to_hass(hass)
+    result = await mock_config_entry.start_reauth_flow(hass)
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "reauth_confirm"
+
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"], {CONF_API_KEY: api_key}
+    )
+    await hass.async_block_till_done()
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "reauth_successful"
+    assert mock_config_entry.data == {CONF_API_KEY: api_key}
+    assert hass.config_entries.async_entries(DOMAIN) == [mock_config_entry]
+    assert mock_config_entry.state is ConfigEntryState.LOADED
+    mock_setup_entry.assert_awaited_once_with(hass, mock_config_entry)
+
+
+@pytest.mark.parametrize(
+    ("error", "message"),
+    [
+        (AxleAuthenticationError(), "invalid_auth"),
+        (AxleConnectionError(), "cannot_connect"),
+        (AxleError(), "cannot_retrieve"),
+    ],
+)
+async def test_reauth_errors(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_client: AsyncMock,
+    mock_setup_entry: AsyncMock,
+    error: Exception,
+    message: str,
+) -> None:
+    """Keep the existing key after a failed replacement and allow a retry."""
+    mock_config_entry.add_to_hass(hass)
+    result = await mock_config_entry.start_reauth_flow(hass)
+    mock_client.get_event.side_effect = error
+
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"], {CONF_API_KEY: "replacement-token"}
+    )
+    await hass.async_block_till_done()
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "reauth_confirm"
+    assert result["errors"] == {"base": message}
+    assert mock_config_entry.data == {CONF_API_KEY: "test-token"}
+    mock_setup_entry.assert_not_called()
+
+    mock_client.get_event.side_effect = None
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"], {CONF_API_KEY: "replacement-token"}
+    )
+    await hass.async_block_till_done()
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "reauth_successful"
+    assert mock_config_entry.data == {CONF_API_KEY: "replacement-token"}
+    assert mock_config_entry.state is ConfigEntryState.LOADED
+    mock_setup_entry.assert_awaited_once_with(hass, mock_config_entry)
+
+
+@pytest.mark.parametrize("api_key", ["replacement-token", "test-token"])
+async def test_reauth_duplicate(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_client: AsyncMock,
+    mock_setup_entry: AsyncMock,
+    api_key: str,
+) -> None:
+    """Keep reauthentication open after a duplicate key and allow a retry."""
+    assert await async_setup_component(hass, DOMAIN, {})
+    mock_config_entry.add_to_hass(hass)
+    other_entry = MockConfigEntry(domain=DOMAIN, data={CONF_API_KEY: "other-token"})
+    other_entry.add_to_hass(hass)
+    result = await mock_config_entry.start_reauth_flow(hass)
+
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"], {CONF_API_KEY: "other-token"}
+    )
+    await hass.async_block_till_done()
+
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "reauth_confirm"
+    assert result["errors"] == {CONF_API_KEY: "already_configured"}
+    assert mock_config_entry.data == {CONF_API_KEY: "test-token"}
+    assert other_entry.data == {CONF_API_KEY: "other-token"}
+    mock_client.get_event.assert_not_called()
+    mock_setup_entry.assert_not_called()
+
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"], {CONF_API_KEY: api_key}
+    )
+    await hass.async_block_till_done()
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "reauth_successful"
+    assert mock_config_entry.data == {CONF_API_KEY: api_key}
+    assert other_entry.data == {CONF_API_KEY: "other-token"}
+    assert hass.config_entries.async_entries(DOMAIN) == [mock_config_entry, other_entry]
+    mock_client.get_event.assert_awaited_once()
+    assert mock_config_entry.state is ConfigEntryState.LOADED
+    mock_setup_entry.assert_awaited_once_with(hass, mock_config_entry)
diff --git a/tests/components/axle_energy/test_sensor.py b/tests/components/axle_energy/test_sensor.py
index fbc1a3de7193..c4485b58f9f2 100644
--- a/tests/components/axle_energy/test_sensor.py
+++ b/tests/components/axle_energy/test_sensor.py
@@ -14,7 +14,11 @@ from freezegun.api import FrozenDateTimeFactory
 import pytest
 from syrupy.assertion import SnapshotAssertion
 
+from homeassistant.components.axle_energy.const import DOMAIN
+from homeassistant.config_entries import SOURCE_REAUTH
+from homeassistant.const import CONF_API_KEY
 from homeassistant.core import HomeAssistant
+from homeassistant.data_entry_flow import FlowResultType
 from homeassistant.helpers import entity_registry as er
 
 from tests.common import MockConfigEntry, async_fire_time_changed, snapshot_platform
@@ -142,7 +146,7 @@ async def test_authentication_failure(
     mock_client: AsyncMock,
     freezer: FrozenDateTimeFactory,
 ) -> None:
-    """Stop polling after the service rejects the credentials."""
+    """Stop polling on rejected credentials and resume after reauthentication."""
     await setup(hass, mock_config_entry)
     mock_client.get_event.side_effect = AxleAuthenticationError()
     freezer.tick(timedelta(minutes=10))
@@ -154,3 +158,22 @@ async def test_authentication_failure(
     async_fire_time_changed(hass)
     await hass.async_block_till_done()
     mock_client.get_event.assert_not_called()
+
+    flows = hass.config_entries.flow.async_progress_by_handler(DOMAIN)
+    assert len(flows) == 1
+    assert flows[0]["context"]["source"] == SOURCE_REAUTH
+    assert flows[0]["context"]["entry_id"] == mock_config_entry.entry_id
+    mock_client.get_event.side_effect = None
+    result = await hass.config_entries.flow.async_configure(
+        flows[0]["flow_id"], {CONF_API_KEY: "replacement-token"}
+    )
+    await hass.async_block_till_done()
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "reauth_successful"
+    assert hass.states.get("sensor.axle_energy_event_type").state == "export"
+
+    mock_client.get_event.reset_mock()
+    freezer.tick(timedelta(minutes=10))
+    async_fire_time_changed(hass)
+    await hass.async_block_till_done()
+    mock_client.get_event.assert_awaited_once()