diff --git a/sync/models/base.py b/sync/models/base.py
index 54a0efd..4593078 100644
--- a/sync/models/base.py
+++ b/sync/models/base.py
@@ -12,6 +12,12 @@ class BaseModel(models.Model):
     class Meta:
         abstract = True
 
+    def get_store_id(self):
+        if isinstance(self, SideStoreModel):
+            return self.store_id
+        else:
+            return None
+
     def get_children_by_model(self):
         """
         Returns a dictionary where:
diff --git a/sync/signals.py b/sync/signals.py
index 55a4303..7e0f093 100644
--- a/sync/signals.py
+++ b/sync/signals.py
@@ -1,4 +1,5 @@
 from django.db.models.signals import pre_save, post_save, pre_delete, post_delete, m2m_changed
+from django.db import models
 from django.dispatch import receiver
 
 from .models import DataAccess, ModelLog, ModelOperation, BaseModel, SideStoreModel
@@ -18,6 +19,39 @@ def synchronization_prepare(sender, instance, created=False, **kwargs):
 
     save_model_log_if_possible(instance, kwargs.get('signal'), created)
 
+@receiver(pre_save)
+def detect_foreign_key_changes(sender, instance, **kwargs):
+    if not hasattr(instance, 'pk') or not instance.pk:
+        return
+    if not isinstance(instance, BaseModel):
+        return
+
+    data_access_list = related_data_access(instance)
+    if data_access_list:
+        try:
+            old_instance = sender.objects.get(pk=instance.pk)
+        except sender.DoesNotExist:
+            return
+
+        # Check foreign key fields
+        for field in sender._meta.get_fields():
+            if isinstance(field, models.ForeignKey):
+                old_value = getattr(old_instance, field.name, None)
+                new_value = getattr(instance, field.name, None)
+                if old_value != new_value:
+                    for data_access in data_access_list:
+                        if old_value:
+                            model_name = old_value.__class__.__name__
+                            save_model_log(data_access.shared_with.all(), 'REVOKE_ACCESS', model_name, old_value.id, old_value.get_store_id())
+                        if new_value:
+                            model_name = new_value.__class__.__name__
+                            save_model_log(data_access.shared_with.all(), 'GRANT_ACCESS', model_name, new_value.id, new_value.get_store_id())
+
+                        # def save_model_log(users, model_operation, model_name, model_id, store_id):
+                        # REVOKE access for old_value and GRANT new_value
+                        print(f"Foreign key changed in {sender.__name__}: "
+                            f"{field.name} from {old_value} to {new_value}")
+
 @receiver([post_save, post_delete])
 def synchronization_notifications(sender, instance, created=False, **kwargs):
     """
@@ -139,7 +173,7 @@ def related_users(instance):
         related_users = [ri.related_user for ri in related_instances if isinstance(ri, BaseModel)]
         users.update(related_users)
 
-        data_access_list = related_data_access(instance, related_instances)
+        data_access_list = instances_related_data_access(instance, related_instances)
         for data_access in data_access_list:
             users.add(data_access.related_user)
             users.update(data_access.shared_with.all())
@@ -149,7 +183,11 @@ def related_users(instance):
 
     return {user for user in users if user is not None}
 
-def related_data_access(instance, related_instances):
+def related_data_access(instance):
+    related_instances = instance.related_instances()
+    return instances_related_data_access(instance, related_instances)
+
+def instances_related_data_access(instance, related_instances):
     # related_instances = instance.related_instances()
     related_ids = [ri.id for ri in related_instances]
     related_ids.append(instance.id)
diff --git a/sync/views.py b/sync/views.py
index fd7eed5..5a0bce0 100644
--- a/sync/views.py
+++ b/sync/views.py
@@ -179,7 +179,6 @@ class SynchronizationApi(HierarchyApiView):
                     self.add_parents_recursively(instance, grants)
                 elif log.operation == 'REVOKE_ACCESS':
                     print(f'revoke access {log.model_id} - {log.store_id}')
-                    # Add to revocations instead of deletions
                     revocations[log.model_name].append({
                         'model_id': log.model_id,
                         'store_id': log.store_id