diff --git a/.env.example b/.env.example
index 5833b23..1fef6db 100644
--- a/.env.example
+++ b/.env.example
@@ -51,10 +51,9 @@ CALDAV_PASSWORD=your-caldav-password
 # - Nextcloud: https://cloud.example.com/remote.php/dav
 # - Fastmail: https://carddav.fastmail.com/dav/addressbooks/user/you@fastmail.com
 # - Radicale: https://radicale.example.com/user/
-CARDDAV_URL=https://carddav.example.com/dav
+CARDDAV_URL=https://carddav.example.com/dav/addressbooks/users/user@example.com/contacts/
 CARDDAV_USERNAME=user@example.com
 CARDDAV_PASSWORD=your-carddav-password
-CONTACTS_ADDRESSBOOK_URL=https://carddav.example.com/dav/addressbooks/users/user@example.com/contacts/
 
 # =============================================================================
 # Cache Configuration
diff --git a/README.md b/README.md
index 13baba5..faa34a7 100644
--- a/README.md
+++ b/README.md
@@ -91,13 +91,12 @@ ICS_CALENDAR_TIMEOUT=20
 ICS_CALENDARS=Team|https://example.com/team.ics,Family|https://example.com/family.ics
 ICS_CALENDAR_TIMEOUT=20
 
-CARDDAV_URL=https://carddav.example.com/dav
+CARDDAV_URL=https://carddav.example.com/dav/addressbooks/users/you@example.com/contacts/
 CARDDAV_USERNAME=you@example.com
 CARDDAV_PASSWORD=your-password
-CONTACTS_ADDRESSBOOK_URL=https://carddav.example.com/dav/addressbooks/users/you@example.com/contacts/
 ```
 
-Contacts tools always use `CONTACTS_ADDRESSBOOK_URL` (full CardDAV address book URL). Listing address books is not exposed via MCP.
+Contacts tools always use `CARDDAV_URL` as the full CardDAV address book URL. Listing address books is not exposed via MCP.
 
 ICS calendars are optional and read-only. Set `ICS_CALENDARS` to a comma-separated list of entries, each as `name|url` or just `url` if you want the name inferred.
 
diff --git a/src/config.py b/src/config.py
index f282acb..026083a 100644
--- a/src/config.py
+++ b/src/config.py
@@ -40,10 +40,6 @@ class Settings(BaseSettings):
     carddav_url: Optional[str] = Field(default=None, alias="CARDDAV_URL")
     carddav_username: Optional[str] = Field(default=None, alias="CARDDAV_USERNAME")
     carddav_password: Optional[SecretStr] = Field(default=None, alias="CARDDAV_PASSWORD")
-    contacts_addressbook_url: Optional[str] = Field(
-        default=None,
-        alias="CONTACTS_ADDRESSBOOK_URL",
-    )
 
     # SQLite Cache
     sqlite_path: str = Field(default="/data/cache.db", alias="SQLITE_PATH")
@@ -154,7 +150,6 @@ class Settings(BaseSettings):
             self.carddav_url,
             self.carddav_username,
             self.carddav_password,
-            self.contacts_addressbook_url,
         ])
 
     def is_notification_configured(self) -> bool:
diff --git a/src/services/contacts_service.py b/src/services/contacts_service.py
index 4581354..92376cf 100644
--- a/src/services/contacts_service.py
+++ b/src/services/contacts_service.py
@@ -495,6 +495,6 @@ class ContactsService:
     def _resolve_addressbook_id(self, addressbook_id: Optional[str]) -> str:
         if addressbook_id:
             return addressbook_id
-        if self.settings.contacts_addressbook_url:
-            return self.settings.contacts_addressbook_url
-        raise ValueError("CONTACTS_ADDRESSBOOK_URL must be set to use contacts tools")
+        if self.settings.carddav_url:
+            return self.settings.carddav_url
+        raise ValueError("CARDDAV_URL must be set to use contacts tools")