diff --git a/homeassistant/components/teslemetry/config_flow.py b/homeassistant/components/teslemetry/config_flow.py
index bd166b3e9f7a..d7efe5aa34e9 100644
--- a/homeassistant/components/teslemetry/config_flow.py
+++ b/homeassistant/components/teslemetry/config_flow.py
@@ -451,6 +451,7 @@ class EnergySiteSubentryFlowHandler(ConfigSubentryFlow):
         self._discovered_host: str = ""
         self._site_id: int | None = None
         self._site_name: str = ""
+        self._approval_expired: bool = False
 
     async def async_step_user(
         self, user_input: dict[str, Any] | None = None
@@ -603,6 +604,11 @@ class EnergySiteSubentryFlowHandler(ConfigSubentryFlow):
         if user_input is None:
             return self.async_show_form(step_id="pair")
 
+        if self._approval_expired:
+            # The user saw the expired-window notice and submitted to try again.
+            self._approval_expired = False
+            return await self._async_begin_pairing()
+
         try:
             client = await self._find_authorized_client()
         except PowerwallLookupError:
@@ -618,6 +624,10 @@ class EnergySiteSubentryFlowHandler(ConfigSubentryFlow):
             return await self.async_step_credentials()
         if client.state == AuthorizedClientState.PENDING_VERIFICATION:
             return self.async_show_form(step_id="pair", errors={"base": "key_pending"})
+        if client.state == AuthorizedClientState.PENDING_VERIFICATION_TIMEOUT:
+            # Surface the expiry; the user's next submit reopens the window.
+            self._approval_expired = True
+            return self.async_show_form(step_id="pair", errors={"base": "key_expired"})
         # An unrecognized state reported as pending would trap the user forever.
         LOGGER.debug("Unrecognized authorized-client state: %s", client.state)
         return self.async_show_form(step_id="pair", errors={"base": "cannot_connect"})
diff --git a/homeassistant/components/teslemetry/strings.json b/homeassistant/components/teslemetry/strings.json
index 1d69696b2b67..09e5e0a0544b 100644
--- a/homeassistant/components/teslemetry/strings.json
+++ b/homeassistant/components/teslemetry/strings.json
@@ -58,6 +58,7 @@
       "error": {
         "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]",
         "invalid_password": "[%key:common::config_flow::error::invalid_auth%]",
+        "key_expired": "The approval window on your Powerwall closed before the key was approved. Submit to open a new window, flick the On/Off switch on your primary Powerwall off and back on to approve it, then submit again.",
         "key_not_approved": "Your Powerwall system rejected Home Assistant's key because it has not been approved. Flick the On/Off switch on your primary Powerwall off and back on to approve it, then submit again.",
         "key_not_registered": "Home Assistant's key is no longer registered on your Powerwall system. Restart setup to register it again.",
         "key_pending": "Home Assistant's key has not been approved yet. Flick the On/Off switch on your primary Powerwall off and back on to approve it, then submit again."
diff --git a/tests/components/teslemetry/test_config_flow.py b/tests/components/teslemetry/test_config_flow.py
index 50db98dd7ed8..f48de8cfb5d1 100644
--- a/tests/components/teslemetry/test_config_flow.py
+++ b/tests/components/teslemetry/test_config_flow.py
@@ -2195,6 +2195,11 @@ async def test_add_authorized_client_failure_aborts(hass: HomeAssistant) -> None
     [
         pytest.param(InvalidResponse(), "cannot_connect", id="lookup_failure"),
         pytest.param(_empty_clients(), "key_not_registered", id="key_not_registered"),
+        pytest.param(
+            _own_key_clients(AuthorizedClientState.PENDING_VERIFICATION_TIMEOUT),
+            "key_expired",
+            id="key_expired",
+        ),
         pytest.param(_own_key_clients("gremlin"), "cannot_connect", id="unknown_state"),
     ],
 )
@@ -2228,6 +2233,69 @@ async def test_pair_step_second_lookup_errors(
     assert result["errors"] == {"base": expected_error}
 
 
+@pytest.mark.usefixtures("mock_rsa_key")
+async def test_pair_step_timeout_retry_reopens_window_and_succeeds(
+    hass: HomeAssistant,
+) -> None:
+    """Submitting the expired form reopens the window and pairing can complete."""
+    entry = await _setup_account_no_subentry(hass)
+
+    client = _mock_powerwall_client()
+    with (
+        patch(
+            "tesla_fleet_api.teslemetry.energysite.TeslemetryEnergySite.find_authorized_clients",
+            new=AsyncMock(
+                side_effect=[
+                    _empty_clients(),
+                    _own_key_clients(
+                        AuthorizedClientState.PENDING_VERIFICATION_TIMEOUT
+                    ),
+                    _own_key_clients(
+                        AuthorizedClientState.PENDING_VERIFICATION_TIMEOUT
+                    ),
+                    _own_key_clients(AuthorizedClientState.VERIFIED),
+                ]
+            ),
+        ),
+        patch(
+            "tesla_fleet_api.teslemetry.energysite.TeslemetryEnergySite.add_authorized_client",
+            new=AsyncMock(),
+        ) as mock_add,
+        patch(
+            "homeassistant.components.teslemetry.config_flow.PowerwallClient",
+            return_value=client,
+        ),
+        patch.object(hass.config_entries, "async_schedule_reload"),
+    ):
+        result = await _start_add_flow_select_site(hass, entry)
+        assert result["step_id"] == "pair"
+
+        result = await hass.config_entries.subentries.async_configure(
+            result["flow_id"], {}
+        )
+        assert result["step_id"] == "pair"
+        assert result["errors"] == {"base": "key_expired"}
+
+        # Submitting the expired form re-registers to open a fresh window.
+        result = await hass.config_entries.subentries.async_configure(
+            result["flow_id"], {}
+        )
+        assert result["step_id"] == "pair"
+
+        result = await hass.config_entries.subentries.async_configure(
+            result["flow_id"], {}
+        )
+        assert result["step_id"] == "credentials"
+
+        result = await hass.config_entries.subentries.async_configure(
+            result["flow_id"], {CONF_HOST: HOST, CONF_PASSWORD: PASSWORD}
+        )
+        await hass.async_block_till_done()
+
+    assert result["type"] is FlowResultType.CREATE_ENTRY
+    assert mock_add.await_count == 2
+
+
 @pytest.mark.usefixtures("mock_rsa_key")
 @pytest.mark.parametrize(
     ("patch_target", "error"),