diff --git a/homeassistant/components/nmbs/sensor.py b/homeassistant/components/nmbs/sensor.py
index 448dda73228..ffb539a39a0 100644
--- a/homeassistant/components/nmbs/sensor.py
+++ b/homeassistant/components/nmbs/sensor.py
@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import logging
+from typing import Any
 
 from pyrail import iRail
 import voluptuous as vol
@@ -180,31 +181,37 @@ class NMBSLiveBoard(SensorEntity):
 
     _attr_attribution = "https://api.irail.be/"
 
-    def __init__(self, api_client, live_station, station_from, station_to):
+    def __init__(
+        self,
+        api_client: iRail,
+        live_station: dict[str, Any],
+        station_from: dict[str, Any],
+        station_to: dict[str, Any],
+    ) -> None:
         """Initialize the sensor for getting liveboard data."""
         self._station = live_station
         self._api_client = api_client
         self._station_from = station_from
         self._station_to = station_to
-        self._attrs = {}
-        self._state = None
+        self._attrs: dict[str, Any] | None = {}
+        self._state: str | None = None
 
         self.entity_registry_enabled_default = False
 
     @property
-    def name(self):
+    def name(self) -> str:
         """Return the sensor default name."""
         return f"Trains in {self._station["standardname"]}"
 
     @property
-    def unique_id(self):
+    def unique_id(self) -> str:
         """Return the unique ID."""
 
         unique_id = f"{self._station}_{self._station_from}_{self._station_to}"
         return f"nmbs_live_{unique_id}"
 
     @property
-    def icon(self):
+    def icon(self) -> str:
         """Return the default icon or an alert icon if delays."""
         if self._attrs and int(self._attrs["delay"]) > 0:
             return DEFAULT_ICON_ALERT
@@ -212,12 +219,12 @@ class NMBSLiveBoard(SensorEntity):
         return DEFAULT_ICON
 
     @property
-    def native_value(self):
+    def native_value(self) -> str | None:
         """Return sensor state."""
         return self._state
 
     @property
-    def extra_state_attributes(self):
+    def extra_state_attributes(self) -> dict[str, Any] | None:
         """Return the sensor attributes if data is available."""
         if self._state is None or not self._attrs:
             return None
@@ -270,8 +277,14 @@ class NMBSSensor(SensorEntity):
     _attr_native_unit_of_measurement = UnitOfTime.MINUTES
 
     def __init__(
-        self, api_client, name, show_on_map, station_from, station_to, excl_vias
-    ):
+        self,
+        api_client: iRail,
+        name: str,
+        show_on_map: bool,
+        station_from: dict[str, Any],
+        station_to: dict[str, Any],
+        excl_vias: bool,
+    ) -> None:
         """Initialize the NMBS connection sensor."""
         self._name = name
         self._show_on_map = show_on_map
@@ -280,7 +293,7 @@ class NMBSSensor(SensorEntity):
         self._station_to = station_to
         self._excl_vias = excl_vias
 
-        self._attrs = {}
+        self._attrs: dict[str, Any] | None = {}
         self._state = None
 
     @property
@@ -298,7 +311,7 @@ class NMBSSensor(SensorEntity):
         return self._name
 
     @property
-    def icon(self):
+    def icon(self) -> str:
         """Return the sensor default icon or an alert icon if any delay."""
         if self._attrs:
             delay = get_delay_in_minutes(self._attrs["departure"]["delay"])
@@ -308,7 +321,7 @@ class NMBSSensor(SensorEntity):
         return "mdi:train"
 
     @property
-    def extra_state_attributes(self):
+    def extra_state_attributes(self) -> dict[str, Any] | None:
         """Return sensor attributes if data is available."""
         if self._state is None or not self._attrs:
             return None
@@ -355,12 +368,12 @@ class NMBSSensor(SensorEntity):
         return attrs
 
     @property
-    def native_value(self):
+    def native_value(self) -> int | None:
         """Return the state of the device."""
         return self._state
 
     @property
-    def station_coordinates(self):
+    def station_coordinates(self) -> list[float]:
         """Get the lat, long coordinates for station."""
         if self._state is None or not self._attrs:
             return []
@@ -370,7 +383,7 @@ class NMBSSensor(SensorEntity):
         return [latitude, longitude]
 
     @property
-    def is_via_connection(self):
+    def is_via_connection(self) -> bool:
         """Return whether the connection goes through another station."""
         if not self._attrs:
             return False