diff --git a/.strict-typing b/.strict-typing
index 24d35370ca5..9cfe0b5a9a7 100644
--- a/.strict-typing
+++ b/.strict-typing
@@ -84,6 +84,7 @@ homeassistant.components.scene.*
 homeassistant.components.select.*
 homeassistant.components.sensor.*
 homeassistant.components.shelly.*
+homeassistant.components.simplisafe.*
 homeassistant.components.slack.*
 homeassistant.components.sonos.media_player
 homeassistant.components.ssdp.*
diff --git a/homeassistant/components/simplisafe/__init__.py b/homeassistant/components/simplisafe/__init__.py
index baf1bcd7b2a..0853aa3974c 100644
--- a/homeassistant/components/simplisafe/__init__.py
+++ b/homeassistant/components/simplisafe/__init__.py
@@ -1,17 +1,28 @@
 """Support for SimpliSafe alarm systems."""
+from __future__ import annotations
+
 import asyncio
+from collections.abc import Awaitable
+from typing import Callable, cast
 from uuid import UUID
 
 from simplipy import get_api
+from simplipy.api import API
 from simplipy.errors import (
     EndpointUnavailableError,
     InvalidCredentialsError,
     SimplipyError,
 )
+from simplipy.sensor.v2 import SensorV2
+from simplipy.sensor.v3 import SensorV3
+from simplipy.system import SystemNotification
+from simplipy.system.v2 import SystemV2
+from simplipy.system.v3 import SystemV3
 import voluptuous as vol
 
+from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import ATTR_CODE, CONF_CODE, CONF_PASSWORD, CONF_USERNAME
-from homeassistant.core import CoreState, callback
+from homeassistant.core import CoreState, HomeAssistant, ServiceCall, callback
 from homeassistant.exceptions import ConfigEntryAuthFailed, ConfigEntryNotReady
 from homeassistant.helpers import (
     aiohttp_client,
@@ -109,7 +120,7 @@ SERVICE_SET_SYSTEM_PROPERTIES_SCHEMA = SERVICE_BASE_SCHEMA.extend(
 CONFIG_SCHEMA = cv.deprecated(DOMAIN)
 
 
-async def async_get_client_id(hass):
+async def async_get_client_id(hass: HomeAssistant) -> str:
     """Get a client ID (based on the HASS unique ID) for the SimpliSafe API.
 
     Note that SimpliSafe requires full, "dashed" versions of UUIDs.
@@ -118,7 +129,9 @@ async def async_get_client_id(hass):
     return str(UUID(hass_id))
 
 
-async def async_register_base_station(hass, system, config_entry_id):
+async def async_register_base_station(
+    hass: HomeAssistant, system: SystemV2 | SystemV3, config_entry_id: str
+) -> None:
     """Register a new bridge."""
     device_registry = await dr.async_get_registry(hass)
     device_registry.async_get_or_create(
@@ -130,11 +143,11 @@ async def async_register_base_station(hass, system, config_entry_id):
     )
 
 
-async def async_setup_entry(hass, config_entry):  # noqa: C901
-    """Set up SimpliSafe as config entry."""
-    hass.data.setdefault(DOMAIN, {DATA_CLIENT: {}})
-    hass.data[DOMAIN][DATA_CLIENT][config_entry.entry_id] = []
-
+@callback
+def _async_standardize_config_entry(
+    hass: HomeAssistant, config_entry: ConfigEntry
+) -> None:
+    """Bring a config entry up to current standards."""
     if CONF_PASSWORD not in config_entry.data:
         raise ConfigEntryAuthFailed("Config schema change requires re-authentication")
 
@@ -154,6 +167,14 @@ async def async_setup_entry(hass, config_entry):  # noqa: C901
     if entry_updates:
         hass.config_entries.async_update_entry(config_entry, **entry_updates)
 
+
+async def async_setup_entry(hass: HomeAssistant, config_entry: ConfigEntry) -> bool:
+    """Set up SimpliSafe as config entry."""
+    hass.data.setdefault(DOMAIN, {DATA_CLIENT: {}})
+    hass.data[DOMAIN][DATA_CLIENT][config_entry.entry_id] = []
+
+    _async_standardize_config_entry(hass, config_entry)
+
     _verify_domain_control = verify_domain_control(hass, DOMAIN)
 
     client_id = await async_get_client_id(hass)
@@ -183,10 +204,12 @@ async def async_setup_entry(hass, config_entry):  # noqa: C901
     hass.config_entries.async_setup_platforms(config_entry, PLATFORMS)
 
     @callback
-    def verify_system_exists(coro):
+    def verify_system_exists(
+        coro: Callable[..., Awaitable]
+    ) -> Callable[..., Awaitable]:
         """Log an error if a service call uses an invalid system ID."""
 
-        async def decorator(call):
+        async def decorator(call: ServiceCall) -> None:
             """Decorate."""
             system_id = int(call.data[ATTR_SYSTEM_ID])
             if system_id not in simplisafe.systems:
@@ -197,10 +220,10 @@ async def async_setup_entry(hass, config_entry):  # noqa: C901
         return decorator
 
     @callback
-    def v3_only(coro):
+    def v3_only(coro: Callable[..., Awaitable]) -> Callable[..., Awaitable]:
         """Log an error if the decorated coroutine is called with a v2 system."""
 
-        async def decorator(call):
+        async def decorator(call: ServiceCall) -> None:
             """Decorate."""
             system = simplisafe.systems[int(call.data[ATTR_SYSTEM_ID])]
             if system.version != 3:
@@ -212,43 +235,40 @@ async def async_setup_entry(hass, config_entry):  # noqa: C901
 
     @verify_system_exists
     @_verify_domain_control
-    async def clear_notifications(call):
+    async def clear_notifications(call: ServiceCall) -> None:
         """Clear all active notifications."""
         system = simplisafe.systems[call.data[ATTR_SYSTEM_ID]]
         try:
             await system.clear_notifications()
         except SimplipyError as err:
             LOGGER.error("Error during service call: %s", err)
-            return
 
     @verify_system_exists
     @_verify_domain_control
-    async def remove_pin(call):
+    async def remove_pin(call: ServiceCall) -> None:
         """Remove a PIN."""
         system = simplisafe.systems[call.data[ATTR_SYSTEM_ID]]
         try:
             await system.remove_pin(call.data[ATTR_PIN_LABEL_OR_VALUE])
         except SimplipyError as err:
             LOGGER.error("Error during service call: %s", err)
-            return
 
     @verify_system_exists
     @_verify_domain_control
-    async def set_pin(call):
+    async def set_pin(call: ServiceCall) -> None:
         """Set a PIN."""
         system = simplisafe.systems[call.data[ATTR_SYSTEM_ID]]
         try:
             await system.set_pin(call.data[ATTR_PIN_LABEL], call.data[ATTR_PIN_VALUE])
         except SimplipyError as err:
             LOGGER.error("Error during service call: %s", err)
-            return
 
     @verify_system_exists
     @v3_only
     @_verify_domain_control
-    async def set_system_properties(call):
+    async def set_system_properties(call: ServiceCall) -> None:
         """Set one or more system parameters."""
-        system = simplisafe.systems[call.data[ATTR_SYSTEM_ID]]
+        system = cast(SystemV3, simplisafe.systems[call.data[ATTR_SYSTEM_ID]])
         try:
             await system.set_properties(
                 {
@@ -259,7 +279,6 @@ async def async_setup_entry(hass, config_entry):  # noqa: C901
             )
         except SimplipyError as err:
             LOGGER.error("Error during service call: %s", err)
-            return
 
     for service, method, schema in (
         ("clear_notifications", clear_notifications, None),
@@ -278,7 +297,7 @@ async def async_setup_entry(hass, config_entry):  # noqa: C901
     return True
 
 
-async def async_unload_entry(hass, entry):
+async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     """Unload a SimpliSafe config entry."""
     unload_ok = await hass.config_entries.async_unload_platforms(entry, PLATFORMS)
     if unload_ok:
@@ -287,7 +306,7 @@ async def async_unload_entry(hass, entry):
     return unload_ok
 
 
-async def async_reload_entry(hass, config_entry):
+async def async_reload_entry(hass: HomeAssistant, config_entry: ConfigEntry) -> None:
     """Handle an options update."""
     await hass.config_entries.async_reload(config_entry.entry_id)
 
@@ -295,17 +314,19 @@ async def async_reload_entry(hass, config_entry):
 class SimpliSafe:
     """Define a SimpliSafe data object."""
 
-    def __init__(self, hass, config_entry, api):
+    def __init__(
+        self, hass: HomeAssistant, config_entry: ConfigEntry, api: API
+    ) -> None:
         """Initialize."""
         self._api = api
         self._hass = hass
-        self._system_notifications = {}
+        self._system_notifications: dict[int, set[SystemNotification]] = {}
         self.config_entry = config_entry
-        self.coordinator = None
-        self.systems = {}
+        self.coordinator: DataUpdateCoordinator | None = None
+        self.systems: dict[int, SystemV2 | SystemV3] = {}
 
     @callback
-    def _async_process_new_notifications(self, system):
+    def _async_process_new_notifications(self, system: SystemV2 | SystemV3) -> None:
         """Act on any new system notifications."""
         if self._hass.state != CoreState.running:
             # If HASS isn't fully running yet, it may cause the SIMPLISAFE_NOTIFICATION
@@ -324,8 +345,6 @@ class SimpliSafe:
 
         LOGGER.debug("New system notifications: %s", to_add)
 
-        self._system_notifications[system.system_id].update(to_add)
-
         for notification in to_add:
             text = notification.text
             if notification.link:
@@ -341,7 +360,9 @@ class SimpliSafe:
                 },
             )
 
-    async def async_init(self):
+        self._system_notifications[system.system_id] = latest_notifications
+
+    async def async_init(self) -> None:
         """Initialize the data class."""
         self.systems = await self._api.get_systems()
         for system in self.systems.values():
@@ -361,10 +382,10 @@ class SimpliSafe:
             update_method=self.async_update,
         )
 
-    async def async_update(self):
+    async def async_update(self) -> None:
         """Get updated data from SimpliSafe."""
 
-        async def async_update_system(system):
+        async def async_update_system(system: SystemV2 | SystemV3) -> None:
             """Update a system."""
             await system.update(cached=system.version != 3)
             self._async_process_new_notifications(system)
@@ -389,8 +410,16 @@ class SimpliSafe:
 class SimpliSafeEntity(CoordinatorEntity):
     """Define a base SimpliSafe entity."""
 
-    def __init__(self, simplisafe, system, name, *, serial=None):
+    def __init__(
+        self,
+        simplisafe: SimpliSafe,
+        system: SystemV2 | SystemV3,
+        name: str,
+        *,
+        serial: str | None = None,
+    ) -> None:
         """Initialize."""
+        assert simplisafe.coordinator
         super().__init__(simplisafe.coordinator)
 
         if serial:
@@ -413,32 +442,33 @@ class SimpliSafeEntity(CoordinatorEntity):
         self._system = system
 
     @property
-    def available(self):
+    def available(self) -> bool:
         """Return whether the entity is available."""
         # We can easily detect if the V3 system is offline, but no simple check exists
         # for the V2 system. Therefore, assuming the coordinator hasn't failed, we mark
         # the entity as available if:
         #   1. We can verify that the system is online (assuming True if we can't)
         #   2. We can verify that the entity is online
-        return (
-            super().available
-            and self._online
-            and not (self._system.version == 3 and self._system.offline)
-        )
+        if isinstance(self._system, SystemV3):
+            system_offline = self._system.offline
+        else:
+            system_offline = False
+
+        return super().available and self._online and not system_offline
 
     @callback
-    def _handle_coordinator_update(self):
+    def _handle_coordinator_update(self) -> None:
         """Update the entity with new REST API data."""
         self.async_update_from_rest_api()
         self.async_write_ha_state()
 
-    async def async_added_to_hass(self):
+    async def async_added_to_hass(self) -> None:
         """Register callbacks."""
         await super().async_added_to_hass()
         self.async_update_from_rest_api()
 
     @callback
-    def async_update_from_rest_api(self):
+    def async_update_from_rest_api(self) -> None:
         """Update the entity with the provided REST API data."""
         raise NotImplementedError()
 
@@ -446,13 +476,22 @@ class SimpliSafeEntity(CoordinatorEntity):
 class SimpliSafeBaseSensor(SimpliSafeEntity):
     """Define a SimpliSafe base (binary) sensor."""
 
-    def __init__(self, simplisafe, system, sensor):
+    def __init__(
+        self,
+        simplisafe: SimpliSafe,
+        system: SystemV2 | SystemV3,
+        sensor: SensorV2 | SensorV3,
+    ) -> None:
         """Initialize."""
         super().__init__(simplisafe, system, sensor.name, serial=sensor.serial)
 
-        self._attr_device_info["identifiers"] = {(DOMAIN, sensor.serial)}
-        self._attr_device_info["model"] = sensor.type.name
-        self._attr_device_info["name"] = sensor.name
+        self._attr_device_info = {
+            "identifiers": {(DOMAIN, sensor.serial)},
+            "manufacturer": "SimpliSafe",
+            "model": sensor.type.name,
+            "name": sensor.name,
+            "via_device": (DOMAIN, system.serial),
+        }
 
         human_friendly_name = " ".join([w.title() for w in sensor.type.name.split("_")])
         self._attr_name = f"{super().name} {human_friendly_name}"
diff --git a/homeassistant/components/simplisafe/alarm_control_panel.py b/homeassistant/components/simplisafe/alarm_control_panel.py
index 28013b69d55..5c50d6a343e 100644
--- a/homeassistant/components/simplisafe/alarm_control_panel.py
+++ b/homeassistant/components/simplisafe/alarm_control_panel.py
@@ -1,8 +1,12 @@
 """Support for SimpliSafe alarm control panels."""
+from __future__ import annotations
+
 import re
 
 from simplipy.errors import SimplipyError
 from simplipy.system import SystemStates
+from simplipy.system.v2 import SystemV2
+from simplipy.system.v3 import SystemV3
 
 from homeassistant.components.alarm_control_panel import (
     FORMAT_NUMBER,
@@ -13,6 +17,7 @@ from homeassistant.components.alarm_control_panel.const import (
     SUPPORT_ALARM_ARM_AWAY,
     SUPPORT_ALARM_ARM_HOME,
 )
+from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import (
     CONF_CODE,
     STATE_ALARM_ARMED_AWAY,
@@ -21,9 +26,10 @@ from homeassistant.const import (
     STATE_ALARM_DISARMED,
     STATE_ALARM_TRIGGERED,
 )
-from homeassistant.core import callback
+from homeassistant.core import HomeAssistant, callback
+from homeassistant.helpers.entity_platform import AddEntitiesCallback
 
-from . import SimpliSafeEntity
+from . import SimpliSafe, SimpliSafeEntity
 from .const import (
     ATTR_ALARM_DURATION,
     ATTR_ALARM_VOLUME,
@@ -48,7 +54,9 @@ ATTR_WALL_POWER_LEVEL = "wall_power_level"
 ATTR_WIFI_STRENGTH = "wifi_strength"
 
 
-async def async_setup_entry(hass, entry, async_add_entities):
+async def async_setup_entry(
+    hass: HomeAssistant, entry: ConfigEntry, async_add_entities: AddEntitiesCallback
+) -> None:
     """Set up a SimpliSafe alarm control panel based on a config entry."""
     simplisafe = hass.data[DOMAIN][DATA_CLIENT][entry.entry_id]
     async_add_entities(
@@ -60,7 +68,7 @@ async def async_setup_entry(hass, entry, async_add_entities):
 class SimpliSafeAlarm(SimpliSafeEntity, AlarmControlPanelEntity):
     """Representation of a SimpliSafe alarm."""
 
-    def __init__(self, simplisafe, system):
+    def __init__(self, simplisafe: SimpliSafe, system: SystemV2 | SystemV3) -> None:
         """Initialize the SimpliSafe alarm."""
         super().__init__(simplisafe, system, "Alarm Control Panel")
 
@@ -91,7 +99,7 @@ class SimpliSafeAlarm(SimpliSafeEntity, AlarmControlPanelEntity):
             self._attr_state = None
 
     @callback
-    def _is_code_valid(self, code, state):
+    def _is_code_valid(self, code: str | None, state: str) -> bool:
         """Validate that a code matches the required one."""
         if not self._simplisafe.config_entry.options.get(CONF_CODE):
             return True
@@ -104,7 +112,7 @@ class SimpliSafeAlarm(SimpliSafeEntity, AlarmControlPanelEntity):
 
         return True
 
-    async def async_alarm_disarm(self, code=None):
+    async def async_alarm_disarm(self, code: str | None = None) -> None:
         """Send disarm command."""
         if not self._is_code_valid(code, STATE_ALARM_DISARMED):
             return
@@ -118,7 +126,7 @@ class SimpliSafeAlarm(SimpliSafeEntity, AlarmControlPanelEntity):
         self._attr_state = STATE_ALARM_DISARMED
         self.async_write_ha_state()
 
-    async def async_alarm_arm_home(self, code=None):
+    async def async_alarm_arm_home(self, code: str | None = None) -> None:
         """Send arm home command."""
         if not self._is_code_valid(code, STATE_ALARM_ARMED_HOME):
             return
@@ -134,7 +142,7 @@ class SimpliSafeAlarm(SimpliSafeEntity, AlarmControlPanelEntity):
         self._attr_state = STATE_ALARM_ARMED_HOME
         self.async_write_ha_state()
 
-    async def async_alarm_arm_away(self, code=None):
+    async def async_alarm_arm_away(self, code: str | None = None) -> None:
         """Send arm away command."""
         if not self._is_code_valid(code, STATE_ALARM_ARMED_AWAY):
             return
@@ -151,9 +159,9 @@ class SimpliSafeAlarm(SimpliSafeEntity, AlarmControlPanelEntity):
         self.async_write_ha_state()
 
     @callback
-    def async_update_from_rest_api(self):
+    def async_update_from_rest_api(self) -> None:
         """Update the entity with the provided REST API data."""
-        if self._system.version == 3:
+        if isinstance(self._system, SystemV3):
             self._attr_extra_state_attributes.update(
                 {
                     ATTR_ALARM_DURATION: self._system.alarm_duration,
@@ -175,9 +183,6 @@ class SimpliSafeAlarm(SimpliSafeEntity, AlarmControlPanelEntity):
                 }
             )
 
-        # Although system state updates are designed the come via the websocket, the
-        # SimpliSafe cloud can sporadically fail to send those updates as expected; so,
-        # just in case, we synchronize the state via the REST API, too:
         if self._system.state == SystemStates.alarm:
             self._attr_state = STATE_ALARM_TRIGGERED
         elif self._system.state == SystemStates.away:
diff --git a/homeassistant/components/simplisafe/binary_sensor.py b/homeassistant/components/simplisafe/binary_sensor.py
index 70fa0fb0e51..1c471d10ce8 100644
--- a/homeassistant/components/simplisafe/binary_sensor.py
+++ b/homeassistant/components/simplisafe/binary_sensor.py
@@ -1,5 +1,9 @@
 """Support for SimpliSafe binary sensors."""
-from simplipy.entity import EntityTypes
+from __future__ import annotations
+
+from simplipy.entity import Entity as SimplipyEntity, EntityTypes
+from simplipy.system.v2 import SystemV2
+from simplipy.system.v3 import SystemV3
 
 from homeassistant.components.binary_sensor import (
     DEVICE_CLASS_BATTERY,
@@ -11,9 +15,11 @@ from homeassistant.components.binary_sensor import (
     DEVICE_CLASS_SMOKE,
     BinarySensorEntity,
 )
-from homeassistant.core import callback
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.core import HomeAssistant, callback
+from homeassistant.helpers.entity_platform import AddEntitiesCallback
 
-from . import SimpliSafeBaseSensor
+from . import SimpliSafe, SimpliSafeBaseSensor
 from .const import DATA_CLIENT, DOMAIN, LOGGER
 
 SUPPORTED_BATTERY_SENSOR_TYPES = [
@@ -39,10 +45,13 @@ TRIGGERED_SENSOR_TYPES = {
 }
 
 
-async def async_setup_entry(hass, entry, async_add_entities):
+async def async_setup_entry(
+    hass: HomeAssistant, entry: ConfigEntry, async_add_entities: AddEntitiesCallback
+) -> None:
     """Set up SimpliSafe binary sensors based on a config entry."""
     simplisafe = hass.data[DOMAIN][DATA_CLIENT][entry.entry_id]
-    sensors = []
+
+    sensors: list[BatteryBinarySensor | TriggeredBinarySensor] = []
 
     for system in simplisafe.systems.values():
         if system.version == 2:
@@ -68,14 +77,20 @@ async def async_setup_entry(hass, entry, async_add_entities):
 class TriggeredBinarySensor(SimpliSafeBaseSensor, BinarySensorEntity):
     """Define a binary sensor related to whether an entity has been triggered."""
 
-    def __init__(self, simplisafe, system, sensor, device_class):
+    def __init__(
+        self,
+        simplisafe: SimpliSafe,
+        system: SystemV2 | SystemV3,
+        sensor: SimplipyEntity,
+        device_class: str,
+    ) -> None:
         """Initialize."""
         super().__init__(simplisafe, system, sensor)
 
         self._attr_device_class = device_class
 
     @callback
-    def async_update_from_rest_api(self):
+    def async_update_from_rest_api(self) -> None:
         """Update the entity with the provided REST API data."""
         self._attr_is_on = self._sensor.triggered
 
@@ -85,13 +100,18 @@ class BatteryBinarySensor(SimpliSafeBaseSensor, BinarySensorEntity):
 
     _attr_device_class = DEVICE_CLASS_BATTERY
 
-    def __init__(self, simplisafe, system, sensor):
+    def __init__(
+        self,
+        simplisafe: SimpliSafe,
+        system: SystemV2 | SystemV3,
+        sensor: SimplipyEntity,
+    ) -> None:
         """Initialize."""
         super().__init__(simplisafe, system, sensor)
 
         self._attr_unique_id = f"{super().unique_id}-battery"
 
     @callback
-    def async_update_from_rest_api(self):
+    def async_update_from_rest_api(self) -> None:
         """Update the entity with the provided REST API data."""
         self._attr_is_on = self._sensor.low_battery
diff --git a/homeassistant/components/simplisafe/config_flow.py b/homeassistant/components/simplisafe/config_flow.py
index ac31779175f..31ae125046c 100644
--- a/homeassistant/components/simplisafe/config_flow.py
+++ b/homeassistant/components/simplisafe/config_flow.py
@@ -1,5 +1,10 @@
 """Config flow to configure the SimpliSafe component."""
+from __future__ import annotations
+
+from typing import Any
+
 from simplipy import get_api
+from simplipy.api import API
 from simplipy.errors import (
     InvalidCredentialsError,
     PendingAuthorizationError,
@@ -8,9 +13,12 @@ from simplipy.errors import (
 import voluptuous as vol
 
 from homeassistant import config_entries
+from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import CONF_CODE, CONF_PASSWORD, CONF_USERNAME
 from homeassistant.core import callback
+from homeassistant.data_entry_flow import FlowResult
 from homeassistant.helpers import aiohttp_client
+from homeassistant.helpers.typing import ConfigType
 
 from . import async_get_client_id
 from .const import DOMAIN, LOGGER
@@ -30,20 +38,25 @@ class SimpliSafeFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
 
     VERSION = 1
 
-    def __init__(self):
+    def __init__(self) -> None:
         """Initialize the config flow."""
-        self._code = None
-        self._password = None
-        self._username = None
+        self._code: str | None = None
+        self._password: str | None = None
+        self._username: str | None = None
 
     @staticmethod
     @callback
-    def async_get_options_flow(config_entry):
+    def async_get_options_flow(
+        config_entry: ConfigEntry,
+    ) -> SimpliSafeOptionsFlowHandler:
         """Define the config flow to handle options."""
         return SimpliSafeOptionsFlowHandler(config_entry)
 
-    async def _async_get_simplisafe_api(self):
+    async def _async_get_simplisafe_api(self) -> API:
         """Get an authenticated SimpliSafe API client."""
+        assert self._username
+        assert self._password
+
         client_id = await async_get_client_id(self.hass)
         websession = aiohttp_client.async_get_clientsession(self.hass)
 
@@ -54,7 +67,9 @@ class SimpliSafeFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
             session=websession,
         )
 
-    async def _async_login_during_step(self, *, step_id, form_schema):
+    async def _async_login_during_step(
+        self, *, step_id: str, form_schema: vol.Schema
+    ) -> FlowResult:
         """Attempt to log into the API from within a config flow step."""
         errors = {}
 
@@ -84,8 +99,10 @@ class SimpliSafeFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
             }
         )
 
-    async def async_step_finish(self, user_input=None):
+    async def async_step_finish(self, user_input: dict[str, Any]) -> FlowResult:
         """Handle finish config entry setup."""
+        assert self._username
+
         existing_entry = await self.async_set_unique_id(self._username)
         if existing_entry:
             self.hass.config_entries.async_update_entry(existing_entry, data=user_input)
@@ -95,7 +112,9 @@ class SimpliSafeFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
             return self.async_abort(reason="reauth_successful")
         return self.async_create_entry(title=self._username, data=user_input)
 
-    async def async_step_mfa(self, user_input=None):
+    async def async_step_mfa(
+        self, user_input: dict[str, Any] | None = None
+    ) -> FlowResult:
         """Handle multi-factor auth confirmation."""
         if user_input is None:
             return self.async_show_form(step_id="mfa")
@@ -116,14 +135,16 @@ class SimpliSafeFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
             }
         )
 
-    async def async_step_reauth(self, config):
+    async def async_step_reauth(self, config: ConfigType) -> FlowResult:
         """Handle configuration by re-auth."""
         self._code = config.get(CONF_CODE)
         self._username = config[CONF_USERNAME]
 
         return await self.async_step_reauth_confirm()
 
-    async def async_step_reauth_confirm(self, user_input=None):
+    async def async_step_reauth_confirm(
+        self, user_input: dict[str, Any] | None = None
+    ) -> FlowResult:
         """Handle re-auth completion."""
         if not user_input:
             return self.async_show_form(
@@ -136,7 +157,9 @@ class SimpliSafeFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
             step_id="reauth_confirm", form_schema=PASSWORD_DATA_SCHEMA
         )
 
-    async def async_step_user(self, user_input=None):
+    async def async_step_user(
+        self, user_input: dict[str, Any] | None = None
+    ) -> FlowResult:
         """Handle the start of the config flow."""
         if not user_input:
             return self.async_show_form(step_id="user", data_schema=FULL_DATA_SCHEMA)
@@ -156,11 +179,13 @@ class SimpliSafeFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
 class SimpliSafeOptionsFlowHandler(config_entries.OptionsFlow):
     """Handle a SimpliSafe options flow."""
 
-    def __init__(self, config_entry):
+    def __init__(self, config_entry: ConfigEntry) -> None:
         """Initialize."""
         self.config_entry = config_entry
 
-    async def async_step_init(self, user_input=None):
+    async def async_step_init(
+        self, user_input: dict[str, Any] | None = None
+    ) -> FlowResult:
         """Manage the options."""
         if user_input is not None:
             return self.async_create_entry(title="", data=user_input)
diff --git a/homeassistant/components/simplisafe/lock.py b/homeassistant/components/simplisafe/lock.py
index 982494d9b1c..e912eedb955 100644
--- a/homeassistant/components/simplisafe/lock.py
+++ b/homeassistant/components/simplisafe/lock.py
@@ -1,11 +1,18 @@
 """Support for SimpliSafe locks."""
+from __future__ import annotations
+
+from typing import Any
+
 from simplipy.errors import SimplipyError
-from simplipy.lock import LockStates
+from simplipy.lock import Lock, LockStates
+from simplipy.system.v3 import SystemV3
 
 from homeassistant.components.lock import LockEntity
-from homeassistant.core import callback
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.core import HomeAssistant, callback
+from homeassistant.helpers.entity_platform import AddEntitiesCallback
 
-from . import SimpliSafeEntity
+from . import SimpliSafe, SimpliSafeEntity
 from .const import DATA_CLIENT, DOMAIN, LOGGER
 
 ATTR_LOCK_LOW_BATTERY = "lock_low_battery"
@@ -13,7 +20,9 @@ ATTR_JAMMED = "jammed"
 ATTR_PIN_PAD_LOW_BATTERY = "pin_pad_low_battery"
 
 
-async def async_setup_entry(hass, entry, async_add_entities):
+async def async_setup_entry(
+    hass: HomeAssistant, entry: ConfigEntry, async_add_entities: AddEntitiesCallback
+) -> None:
     """Set up SimpliSafe locks based on a config entry."""
     simplisafe = hass.data[DOMAIN][DATA_CLIENT][entry.entry_id]
     locks = []
@@ -32,13 +41,13 @@ async def async_setup_entry(hass, entry, async_add_entities):
 class SimpliSafeLock(SimpliSafeEntity, LockEntity):
     """Define a SimpliSafe lock."""
 
-    def __init__(self, simplisafe, system, lock):
+    def __init__(self, simplisafe: SimpliSafe, system: SystemV3, lock: Lock) -> None:
         """Initialize."""
         super().__init__(simplisafe, system, lock.name, serial=lock.serial)
 
         self._lock = lock
 
-    async def async_lock(self, **kwargs):
+    async def async_lock(self, **kwargs: dict[str, Any]) -> None:
         """Lock the lock."""
         try:
             await self._lock.lock()
@@ -49,7 +58,7 @@ class SimpliSafeLock(SimpliSafeEntity, LockEntity):
         self._attr_is_locked = True
         self.async_write_ha_state()
 
-    async def async_unlock(self, **kwargs):
+    async def async_unlock(self, **kwargs: dict[str, Any]) -> None:
         """Unlock the lock."""
         try:
             await self._lock.unlock()
@@ -61,7 +70,7 @@ class SimpliSafeLock(SimpliSafeEntity, LockEntity):
         self.async_write_ha_state()
 
     @callback
-    def async_update_from_rest_api(self):
+    def async_update_from_rest_api(self) -> None:
         """Update the entity with the provided REST API data."""
         self._attr_extra_state_attributes.update(
             {
diff --git a/homeassistant/components/simplisafe/manifest.json b/homeassistant/components/simplisafe/manifest.json
index 3ec1e38ad4d..8c23e575cc3 100644
--- a/homeassistant/components/simplisafe/manifest.json
+++ b/homeassistant/components/simplisafe/manifest.json
@@ -3,7 +3,7 @@
   "name": "SimpliSafe",
   "config_flow": true,
   "documentation": "https://www.home-assistant.io/integrations/simplisafe",
-  "requirements": ["simplisafe-python==11.0.2"],
+  "requirements": ["simplisafe-python==11.0.3"],
   "codeowners": ["@bachya"],
   "iot_class": "cloud_polling"
 }
diff --git a/homeassistant/components/simplisafe/sensor.py b/homeassistant/components/simplisafe/sensor.py
index 76be7b6e4f0..149319cd5bd 100644
--- a/homeassistant/components/simplisafe/sensor.py
+++ b/homeassistant/components/simplisafe/sensor.py
@@ -2,14 +2,18 @@
 from simplipy.entity import EntityTypes
 
 from homeassistant.components.sensor import SensorEntity
+from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import DEVICE_CLASS_TEMPERATURE, TEMP_FAHRENHEIT
-from homeassistant.core import callback
+from homeassistant.core import HomeAssistant, callback
+from homeassistant.helpers.entity_platform import AddEntitiesCallback
 
 from . import SimpliSafeBaseSensor
 from .const import DATA_CLIENT, DOMAIN, LOGGER
 
 
-async def async_setup_entry(hass, entry, async_add_entities):
+async def async_setup_entry(
+    hass: HomeAssistant, entry: ConfigEntry, async_add_entities: AddEntitiesCallback
+) -> None:
     """Set up SimpliSafe freeze sensors based on a config entry."""
     simplisafe = hass.data[DOMAIN][DATA_CLIENT][entry.entry_id]
     sensors = []
@@ -33,6 +37,6 @@ class SimplisafeFreezeSensor(SimpliSafeBaseSensor, SensorEntity):
     _attr_unit_of_measurement = TEMP_FAHRENHEIT
 
     @callback
-    def async_update_from_rest_api(self):
+    def async_update_from_rest_api(self) -> None:
         """Update the entity with the provided REST API data."""
         self._attr_state = self._sensor.temperature
diff --git a/mypy.ini b/mypy.ini
index 409dbbdab76..613a4e3335d 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -935,6 +935,17 @@ no_implicit_optional = true
 warn_return_any = true
 warn_unreachable = true
 
+[mypy-homeassistant.components.simplisafe.*]
+check_untyped_defs = true
+disallow_incomplete_defs = true
+disallow_subclassing_any = true
+disallow_untyped_calls = true
+disallow_untyped_decorators = true
+disallow_untyped_defs = true
+no_implicit_optional = true
+warn_return_any = true
+warn_unreachable = true
+
 [mypy-homeassistant.components.slack.*]
 check_untyped_defs = true
 disallow_incomplete_defs = true
diff --git a/requirements_all.txt b/requirements_all.txt
index b23f28caafd..7cf7390d0ca 100644
--- a/requirements_all.txt
+++ b/requirements_all.txt
@@ -2107,7 +2107,7 @@ simplehound==0.3
 simplepush==1.1.4
 
 # homeassistant.components.simplisafe
-simplisafe-python==11.0.2
+simplisafe-python==11.0.3
 
 # homeassistant.components.sisyphus
 sisyphus-control==3.0
diff --git a/requirements_test_all.txt b/requirements_test_all.txt
index fd290d3bfe8..14bf97ad2da 100644
--- a/requirements_test_all.txt
+++ b/requirements_test_all.txt
@@ -1156,7 +1156,7 @@ sharkiqpy==0.1.8
 simplehound==0.3
 
 # homeassistant.components.simplisafe
-simplisafe-python==11.0.2
+simplisafe-python==11.0.3
 
 # homeassistant.components.slack
 slackclient==2.5.0