diff --git a/src/api/events.py b/src/api/events.py
index 2d8e4dd..f70ab52 100644
--- a/src/api/events.py
+++ b/src/api/events.py
@@ -12,7 +12,16 @@ from src.db.models.category import Category
 from src.db.models.event import Event
 from src.db.models.invitation import Invitation
 from src.db.models.user import User
-from src.utils.db import MissingIdError, UnfetchedLinkError, expr, from_id_list, get_id_list, update_document
+from src.db.types import BeanieLink
+from src.utils.db import (
+    IdNotFoundError,
+    MissingIdError,
+    UnfetchedLinkError,
+    expr,
+    from_id_list,
+    get_id_list,
+    update_document,
+)
 from src.utils.logging import get_logger
 
 from .auth import CurrentUserDep
@@ -90,16 +99,37 @@ class EventCreateData(_BaseEventData):
     This structure is intended to be used for POST & PUT requests.
     """
 
-    async def create_event(self, user: User) -> Event:
+    async def create_event(self, user: User, category_owner_check: bool = True) -> Event:
         """Create a new event in the database.
 
-        If one of the attendees or categories is not found, IdNotFoundError will be raised.
+        If one of the categories is not found, HTTPException with code 404 will be raised.
+
+        If `category_owner_check` is set to True, the function will check if the user
+        is the owner of all categories. If not, HTTPException with code 403 will be raised.
         """
+        try:
+            categories = await from_id_list(self.category_ids, Category)
+        except IdNotFoundError as exc:
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND,
+                detail=f"Category with id {exc.item_id} doesn't exist",
+            )
+
+        if category_owner_check:
+            for category in categories:
+                await category.fetch_link(Category.user)
+
+                if cast(User, category.user).id != user.id:
+                    raise HTTPException(
+                        status_code=status.HTTP_403_FORBIDDEN,
+                        detail="You can only create events with your own categories",
+                    )
+
         event = Event(
             user=user,
             title=self.title,
             description=self.description,
-            categories=await from_id_list(self.category_ids, Category, link_return=True),
+            categories=cast(list[BeanieLink[Category]], categories),
             start_time=self.start_time,
             end_time=self.end_time,
             color=self.color.as_hex(format="long"),