diff --git a/homeassistant/components/notify/__init__.py b/homeassistant/components/notify/__init__.py
index f9b0a64db3d..75b4b65ac5b 100644
--- a/homeassistant/components/notify/__init__.py
+++ b/homeassistant/components/notify/__init__.py
@@ -20,6 +20,7 @@ from homeassistant.helpers.entity_component import EntityComponent
 from homeassistant.helpers.restore_state import RestoreEntity
 from homeassistant.helpers.typing import ConfigType
 from homeassistant.util import dt as dt_util
+from homeassistant.util.hass_dict import HassKey
 
 from .const import (  # noqa: F401
     ATTR_DATA,
@@ -46,6 +47,7 @@ from .repairs import migrate_notify_issue  # noqa: F401
 # Platform specific data
 ATTR_TITLE_DEFAULT = "Home Assistant"
 
+DOMAIN_DATA: HassKey[EntityComponent[NotifyEntity]] = HassKey(DOMAIN)
 ENTITY_ID_FORMAT = DOMAIN + ".{}"
 
 MIN_TIME_BETWEEN_SCANS = timedelta(seconds=10)
@@ -76,7 +78,9 @@ async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
         # legacy platforms to finish setting up.
         hass.async_create_task(setup, eager_start=True)
 
-    component = hass.data[DOMAIN] = EntityComponent[NotifyEntity](_LOGGER, DOMAIN, hass)
+    component = hass.data[DOMAIN_DATA] = EntityComponent[NotifyEntity](
+        _LOGGER, DOMAIN, hass
+    )
     component.async_register_entity_service(
         SERVICE_SEND_MESSAGE,
         {
@@ -113,14 +117,12 @@ class NotifyEntityDescription(EntityDescription, frozen_or_thawed=True):
 
 async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     """Set up a config entry."""
-    component: EntityComponent[NotifyEntity] = hass.data[DOMAIN]
-    return await component.async_setup_entry(entry)
+    return await hass.data[DOMAIN_DATA].async_setup_entry(entry)
 
 
 async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     """Unload a config entry."""
-    component: EntityComponent[NotifyEntity] = hass.data[DOMAIN]
-    return await component.async_unload_entry(entry)
+    return await hass.data[DOMAIN_DATA].async_unload_entry(entry)
 
 
 class NotifyEntity(RestoreEntity):
diff --git a/homeassistant/components/notify/legacy.py b/homeassistant/components/notify/legacy.py
index a210e80242e..46538aad921 100644
--- a/homeassistant/components/notify/legacy.py
+++ b/homeassistant/components/notify/legacy.py
@@ -3,13 +3,13 @@
 from __future__ import annotations
 
 import asyncio
-from collections.abc import Callable, Coroutine, Mapping
+from collections.abc import Coroutine, Mapping
 from functools import partial
 from typing import Any, Protocol, cast
 
 from homeassistant.config import config_per_platform
 from homeassistant.const import CONF_DESCRIPTION, CONF_NAME
-from homeassistant.core import HomeAssistant, ServiceCall, callback
+from homeassistant.core import CALLBACK_TYPE, HomeAssistant, ServiceCall, callback
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers import discovery
 from homeassistant.helpers.service import async_set_service_schema
@@ -21,6 +21,7 @@ from homeassistant.setup import (
     async_start_setup,
 )
 from homeassistant.util import slugify
+from homeassistant.util.hass_dict import HassKey
 from homeassistant.util.yaml import load_yaml_dict
 
 from .const import (
@@ -35,8 +36,12 @@ from .const import (
 )
 
 CONF_FIELDS = "fields"
-NOTIFY_SERVICES = "notify_services"
-NOTIFY_DISCOVERY_DISPATCHER = "notify_discovery_dispatcher"
+NOTIFY_SERVICES: HassKey[dict[str, list[BaseNotificationService]]] = HassKey(
+    f"{DOMAIN}_services"
+)
+NOTIFY_DISCOVERY_DISPATCHER: HassKey[CALLBACK_TYPE | None] = HassKey(
+    f"{DOMAIN}_discovery_dispatcher"
+)
 
 
 class LegacyNotifyPlatform(Protocol):
@@ -160,11 +165,9 @@ async def async_reload(hass: HomeAssistant, integration_name: str) -> None:
     if not _async_integration_has_notify_services(hass, integration_name):
         return
 
-    notify_services: list[BaseNotificationService] = hass.data[NOTIFY_SERVICES][
-        integration_name
-    ]
     tasks = [
-        notify_service.async_register_services() for notify_service in notify_services
+        notify_service.async_register_services()
+        for notify_service in hass.data[NOTIFY_SERVICES][integration_name]
     ]
 
     await asyncio.gather(*tasks)
@@ -173,20 +176,16 @@ async def async_reload(hass: HomeAssistant, integration_name: str) -> None:
 @bind_hass
 async def async_reset_platform(hass: HomeAssistant, integration_name: str) -> None:
     """Unregister notify services for an integration."""
-    notify_discovery_dispatcher: Callable[[], None] | None = hass.data.get(
-        NOTIFY_DISCOVERY_DISPATCHER
-    )
+    notify_discovery_dispatcher = hass.data.get(NOTIFY_DISCOVERY_DISPATCHER)
     if notify_discovery_dispatcher:
         notify_discovery_dispatcher()
         hass.data[NOTIFY_DISCOVERY_DISPATCHER] = None
     if not _async_integration_has_notify_services(hass, integration_name):
         return
 
-    notify_services: list[BaseNotificationService] = hass.data[NOTIFY_SERVICES][
-        integration_name
-    ]
     tasks = [
-        notify_service.async_unregister_services() for notify_service in notify_services
+        notify_service.async_unregister_services()
+        for notify_service in hass.data[NOTIFY_SERVICES][integration_name]
     ]
 
     await asyncio.gather(*tasks)