diff --git a/app/communication/enums.py b/app/communication/enums.py
index 60cb68ac1..d9c6fc606 100644
--- a/app/communication/enums.py
+++ b/app/communication/enums.py
@@ -15,3 +15,6 @@ class UserNotificationSettingType(models.TextChoices):
     FINE = "FINE", "Grupper - bot"
     GROUP_MEMBERSHIP = "GROUP_MEMBERSHIP", "Grupper - medlemsskap"
     OTHER = "OTHER", "Andre"
+    RESERVATION_NEW = "RESERVATION NEW", "Ny reservasjon"
+    RESERVATION_APPROVED = "RESERVATION APPROVED", "Godkjent reservasjon"
+    RESERVATION_CANCELLED = "RESERVATION CANCELLED", "Avslått reservasjon"
diff --git a/app/communication/migrations/0010_alter_usernotificationsetting_notification_type.py b/app/communication/migrations/0010_alter_usernotificationsetting_notification_type.py
new file mode 100644
index 000000000..87c08c700
--- /dev/null
+++ b/app/communication/migrations/0010_alter_usernotificationsetting_notification_type.py
@@ -0,0 +1,35 @@
+# Generated by Django 4.2.5 on 2024-04-10 16:30
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("communication", "0009_alter_usernotificationsetting_notification_type"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="usernotificationsetting",
+            name="notification_type",
+            field=models.CharField(
+                choices=[
+                    ("REGISTRATION", "Påmeldingsoppdateringer"),
+                    ("UNREGISTRATION", "Avmeldingsoppdateringer"),
+                    ("STRIKE", "Prikkoppdateringer"),
+                    ("EVENT_SIGN_UP_START", "Arrangementer - påmeldingsstart"),
+                    ("EVENT_SIGN_OFF_DEADLINE", "Arrangementer - avmeldingsfrist"),
+                    ("EVENT_EVALUATION", "Arrangementer - evaluering"),
+                    ("EVENT_INFO", "Arrangementer - info fra arrangør"),
+                    ("FINE", "Grupper - bot"),
+                    ("GROUP_MEMBERSHIP", "Grupper - medlemsskap"),
+                    ("OTHER", "Andre"),
+                    ("RESERVATION NEW", "Ny reservasjon"),
+                    ("RESERVATION APPROVED", "Godkjent reservasjon"),
+                    ("RESERVATION CANCELLED", "Avslått reservasjon"),
+                ],
+                max_length=30,
+            ),
+        ),
+    ]
diff --git a/app/kontres/models/reservation.py b/app/kontres/models/reservation.py
index f73fbc0a1..22f544cae 100644
--- a/app/kontres/models/reservation.py
+++ b/app/kontres/models/reservation.py
@@ -2,10 +2,12 @@
 
 from django.db import models
 
-from app.common.enums import AdminGroup, Groups
+from app.common.enums import AdminGroup, Groups, MembershipType
 from app.common.permissions import BasePermissionModel, check_has_access
+from app.communication.enums import UserNotificationSettingType
+from app.communication.notifier import Notify
 from app.content.models import User
-from app.group.models import Group
+from app.group.models import Group, Membership
 from app.kontres.enums import ReservationStateEnum
 from app.kontres.models.bookable_item import BookableItem
 from app.util.models import BaseModel
@@ -110,3 +112,44 @@ def has_object_update_permission(self, request):
 
     def is_own_reservation(self, request):
         return self.author == request.user
+
+    def notify_admins_new_reservation(self):
+        formatted_start_time = self.start_time.strftime("%d/%m %H:%M")
+
+        leader_membership = Membership.objects.filter(
+            group=Group.objects.get(pk="kontkom"), membership_type=MembershipType.LEADER
+        ).first()
+
+        if leader_membership is None:
+            return
+
+        notification_message = (
+            f"En ny reservasjon er opprettet for {self.bookable_item.name}, "
+            f"planlagt til {formatted_start_time}."
+        )
+
+        Notify(
+            users=[leader_membership.user],
+            title="Ny Reservasjon Laget",
+            notification_type=UserNotificationSettingType.RESERVATION_NEW,
+        ).add_paragraph(notification_message).send()
+
+    def notify_approved(self):
+        formatted_date_time = self.start_time.strftime("%d/%m %H:%M")
+        Notify(
+            [self.author],
+            f'Reservasjonssøknad for "{self.bookable_item.name} er godkjent."',
+            UserNotificationSettingType.RESERVATION_APPROVED,
+        ).add_paragraph(
+            f"Hei, {self.author.first_name}! Din søknad for å reservere {self.bookable_item.name}, den {formatted_date_time} har blitt godkjent."
+        ).send()
+
+    def notify_denied(self):
+        formatted_date_time = self.start_time.strftime("%d/%m %H:%M")
+        Notify(
+            [self.author],
+            f'Reservasjonssøknad for "{self.bookable_item.name}" er avslått.',
+            UserNotificationSettingType.RESERVATION_CANCELLED,
+        ).add_paragraph(
+            f"Hei, {self.author.first_name}! Din søknad for å reservere {self.bookable_item.name}, den {formatted_date_time} har blitt avslått. Du kan ta kontakt med Kontor og Kiosk dersom du lurer på noe ifm. dette."
+        ).send()
diff --git a/app/kontres/views/reservation.py b/app/kontres/views/reservation.py
index d3ab071fe..1a0165fdc 100644
--- a/app/kontres/views/reservation.py
+++ b/app/kontres/views/reservation.py
@@ -59,17 +59,28 @@ def update(self, request, *args, **kwargs):
         serializer = self.get_serializer(reservation, data=request.data, partial=True)
         serializer.is_valid(raise_exception=True)
 
-        # Check if the state is being updated to CONFIRMED and set approved_by
-        if (
-            "state" in serializer.validated_data
-            and serializer.validated_data["state"] == ReservationStateEnum.CONFIRMED
-            and reservation.state != ReservationStateEnum.CONFIRMED
-        ):
-            serializer.save(approved_by=request.user)
-        else:
-            serializer.save()
+        if serializer.is_valid():
+            previous_state = reservation.state
+            new_state = serializer.validated_data.get("state")
+
+            # Check if the state is being updated to CONFIRMED and set approved_by
+            if (
+                new_state == ReservationStateEnum.CONFIRMED
+                and previous_state != ReservationStateEnum.CONFIRMED
+            ):
+                serializer.save(approved_by=request.user)
+            else:
+                serializer.save()
+
+            if new_state and new_state != previous_state:
+                if new_state == ReservationStateEnum.CONFIRMED:
+                    serializer.instance.notify_approved()
+                elif new_state == ReservationStateEnum.CANCELLED:
+                    serializer.instance.notify_denied()
 
-        return Response(serializer.data, status=status.HTTP_200_OK)
+            return Response(serializer.data, status=status.HTTP_200_OK)
+        else:
+            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
 
     def destroy(self, request, *args, **kwargs):
         super().destroy(self, request, *args, **kwargs)