diff --git a/custom_components/ecocito/client.py b/custom_components/ecocito/client.py
index 8658016..d4084a0 100644
--- a/custom_components/ecocito/client.py
+++ b/custom_components/ecocito/client.py
@@ -14,6 +14,9 @@ from .const import (
     ECOCITO_COLLECTION_ENDPOINT,
     ECOCITO_COLLECTION_TYPE_ENDPOINT,
     ECOCITO_DEFAULT_COLLECTION_TYPE,
+    ECOCITO_ERROR_AUTHENTICATION,
+    ECOCITO_ERROR_FETCHING,
+    ECOCITO_ERROR_UNHANDLED,
     ECOCITO_GARBAGE_COLLECTION_TYPE,
     ECOCITO_LOGIN_ENDPOINT,
     ECOCITO_LOGIN_PASSWORD_KEY,
@@ -78,7 +81,7 @@ class EcocitoClient:
                         raise InvalidAuthenticationError(error[0].find("li").text)
                     LOGGER.debug("Connected as %s", self._username)
             except aiohttp.ClientError as e:
-                raise EcocitoError(f"Authentication error: {e}") from e
+                raise EcocitoError(ECOCITO_ERROR_AUTHENTICATION.format(exc=e)) from e
 
     async def get_collection_types(self) -> dict:
         """Return the mapping of collection type ID with their label."""
@@ -100,7 +103,9 @@ class EcocitoClient:
                     except Exception as e:  # noqa: BLE001
                         await self._handle_error(content, e)
             except aiohttp.ClientError as e:
-                raise EcocitoError(f"Unable to get collection types: {e}") from e
+                raise EcocitoError(
+                    ECOCITO_ERROR_FETCHING.format(exc=e, type="collection types")
+                ) from e
 
     async def get_collection_events(
         self, event_type: str, year: int
@@ -138,7 +143,9 @@ class EcocitoClient:
                             await self._handle_error(content, e)
 
             except aiohttp.ClientError as e:
-                raise EcocitoError(f"Unable to get collection events: {e}") from e
+                raise EcocitoError(
+                    ECOCITO_ERROR_FETCHING.format(exc=e, type="collection events")
+                ) from e
 
     async def get_garbage_collections(self, year: int) -> list[CollectionEvent]:
         """Return the list of the garbage collections for a year."""
@@ -179,10 +186,12 @@ class EcocitoClient:
                             await self._handle_error(content, e)
 
             except aiohttp.ClientError as e:
-                raise EcocitoError(f"Unable to get waste deposit visits: {e}") from e
+                raise EcocitoError(
+                    ECOCITO_ERROR_FETCHING.format(exc=e, type="waste deposit events")
+                ) from e
 
-    async def _handle_error(self, content: str, e: Exception):
-        """Handle a request error by checking for login form and re-authenticating if necessary."""
+    async def _handle_error(self, content: str, e: Exception) -> None:
+        """Handle request errors by checking for login form and re-auth if necessary."""
         html = bs(content, "html.parser")
         form = html.find("form", action=re.compile(f"{ECOCITO_LOGIN_URI}"))
 
@@ -190,4 +199,4 @@ class EcocitoClient:
             LOGGER.debug("The session has expired, try to login again.")
             await self.authenticate()
         else:
-            raise EcocitoError("Unhandled request error") from e
+            raise EcocitoError(ECOCITO_ERROR_UNHANDLED) from e
diff --git a/custom_components/ecocito/const.py b/custom_components/ecocito/const.py
index 096ea5f..2ccf4f1 100644
--- a/custom_components/ecocito/const.py
+++ b/custom_components/ecocito/const.py
@@ -8,18 +8,15 @@ LOGGER = logging.getLogger(__package__)
 # Config Flow
 
 # Service Device
-
 DEVICE_ATTRIBUTION = "Données fournies par Ecocito"
 DEVICE_NAME = "Ecocito"
 DEVICE_MANUFACTURER = "Ecocito"
 DEVICE_MODEL = "Calendrier Ecocito"
 
 # Ecocito - Base
-
 ECOCITO_DOMAIN = "{}.ecocito.com"
 
 # Ecocito - Login
-
 ECOCITO_LOGIN_URI = "/Usager/Profil/Connexion"
 ECOCITO_LOGIN_ENDPOINT = f"https://{ECOCITO_DOMAIN}{ECOCITO_LOGIN_URI}"
 ECOCITO_LOGIN_USERNAME_KEY = "Identifiant"
@@ -36,3 +33,12 @@ ECOCITO_COLLECTION_TYPE_ENDPOINT = f"https://{ECOCITO_DOMAIN}/Usager/Collecte"
 
 # Ecocito - Waste deposit visits
 ECOCITO_WASTE_DEPOSIT_ENDPOINT = f"https://{ECOCITO_DOMAIN}/Usager/Apport/GetApport"
+
+# Ecocito - Errors
+ECOCITO_ERROR_AUTHENTICATION = "Authentication error: {exc}"
+ECOCITO_ERROR_FETCHING = "Unable to get {type}: {exc}"
+ECOCITO_ERROR_UNHANDLED = "Unhandled request error"
+
+ECOCITO_MESSAGE_REAUTHENTICATE = (
+    "Credentials are no longer valid. Please reauthenticate"
+)
diff --git a/custom_components/ecocito/coordinator.py b/custom_components/ecocito/coordinator.py
index 9a23e0f..18dd62f 100644
--- a/custom_components/ecocito/coordinator.py
+++ b/custom_components/ecocito/coordinator.py
@@ -13,7 +13,7 @@ from homeassistant.exceptions import ConfigEntryAuthFailed
 from homeassistant.helpers.update_coordinator import DataUpdateCoordinator, UpdateFailed
 
 from .client import CollectionEvent, EcocitoClient, WasteDepotVisit
-from .const import DOMAIN, LOGGER
+from .const import DOMAIN, ECOCITO_MESSAGE_REAUTHENTICATE, LOGGER
 from .errors import CannotConnectError, InvalidAuthenticationError
 
 T = TypeVar("T", bound=list[CollectionEvent] | list[WasteDepotVisit])
@@ -46,9 +46,7 @@ class EcocitoDataUpdateCoordinator(DataUpdateCoordinator[T], Generic[T], ABC):
         except CannotConnectError as ex:
             raise UpdateFailed(ex) from ex
         except InvalidAuthenticationError as ex:
-            raise ConfigEntryAuthFailed(
-                "Credentials are no longer valid. Please reauthenticate"
-            ) from ex
+            raise ConfigEntryAuthFailed(ECOCITO_MESSAGE_REAUTHENTICATE) from ex
 
     @abstractmethod
     async def _fetch_data(self) -> T: