diff --git a/backend/app/dav/carddav.py b/backend/app/dav/carddav.py
index a76b7cb..cd1f3b4 100644
--- a/backend/app/dav/carddav.py
+++ b/backend/app/dav/carddav.py
@@ -19,7 +19,10 @@ from flask import Response, request
 from app.extensions import db
 from app.models.contact import AddressBook, Contact, AddressBookShare
 from app.models.user import User
-from app.api.contacts import _apply_fields_to_contact, _build_vcard, parse_vcard
+from app.api.contacts import (
+    _apply_fields_to_contact, _build_vcard, parse_vcard,
+    _notify_addressbook, _book_recipients,
+)
 
 from . import dav_bp
 from .caldav import (
@@ -277,7 +280,8 @@ def ab_put(username, ab_part, filename):
     if if_match and existing and if_match.strip() != _etag_for_contact(existing):
         return Response('', 412)
 
-    if not existing:
+    is_new = existing is None
+    if is_new:
         existing = Contact(address_book_id=book.id, uid=body_uid, vcard_data=raw)
         db.session.add(existing)
 
@@ -288,7 +292,9 @@ def ab_put(username, ab_part, filename):
     existing.vcard_data = raw.strip() or _build_vcard(existing)
     existing.updated_at = datetime.now(timezone.utc)
     db.session.commit()
-    status = 201 if not if_match else 204
+    _notify_addressbook(book.owner_id, book.id, 'contact',
+                        shared_with=_book_recipients(book))
+    status = 201 if is_new else 204
     return Response('', status, {'ETag': _etag_for_contact(existing)})
 
 
@@ -308,6 +314,8 @@ def ab_delete(username, ab_part, filename):
         return Response('', 404)
     db.session.delete(contact)
     db.session.commit()
+    _notify_addressbook(book.owner_id, book.id, 'contact',
+                        shared_with=_book_recipients(book))
     return Response('', 204)
 
 
@@ -324,8 +332,12 @@ def ab_delete_collection(username, ab_part):
     book = _addressbook_for(user, book_id) if book_id else None
     if not book:
         return Response('', 404)
+    recipients = _book_recipients(book)
+    owner_id = book.owner_id
+    book_id = book.id
     db.session.delete(book)
     db.session.commit()
+    _notify_addressbook(owner_id, book_id, 'deleted', shared_with=recipients)
     return Response('', 204)
 
 
@@ -351,4 +363,5 @@ def ab_mkcol(username, ab_part):
     book = AddressBook(owner_id=user.id, name=name)
     db.session.add(book)
     db.session.commit()
+    _notify_addressbook(user.id, book.id, 'created')
     return Response('', 201, {'Location': _href_addressbook(user.username, book.id)})