diff --git a/api/utils/serializer/v1/compensation.py b/api/utils/serializer/v1/compensation.py
index 05787795..e2ec2609 100644
--- a/api/utils/serializer/v1/compensation.py
+++ b/api/utils/serializer/v1/compensation.py
@@ -78,16 +78,21 @@ class CompensationAPISerializerV1(AbstractModelAPISerializerV1, AbstractCompensa
         Returns:
             obj (Compensation)
         """
+        if obj.intervention.id == intervention_id:
+            # Nothing to do here
+            return obj
+
         intervention = Intervention.objects.get(
             id=intervention_id,
         )
         is_shared = intervention.is_shared_with(user)
+
         if not is_shared:
             raise PermissionError("Intervention not shared with user")
+
         obj.intervention = intervention
         return obj
 
-
     def create_model_from_json(self, json_model, user):
         """ Creates a new entry for the model based on the contents of json_model
 
@@ -123,6 +128,23 @@ class CompensationAPISerializerV1(AbstractModelAPISerializerV1, AbstractCompensa
 
             return obj.id
 
+    def get_obj_from_db(self, id, user):
+        """ Returns the object from database
+
+        Fails if id not found or user does not have shared access
+
+        Args:
+            id (str): The object's id
+            user (User): The API user
+
+        Returns:
+
+        """
+        return self.model.objects.get(
+            id=id,
+            intervention__users__in=[user]
+        )
+
     def update_model_from_json(self, id, json_model, user):
         """ Updates an entry for the model based on the contents of json_model
 
@@ -135,21 +157,28 @@ class CompensationAPISerializerV1(AbstractModelAPISerializerV1, AbstractCompensa
             created_id (str): The id of the newly created Compensation entry
         """
         with transaction.atomic():
+            update_action = UserActionLogEntry.get_edited_action(user, "API update")
             obj = self.get_obj_from_db(id, user)
 
             # Fill in data to objects
             properties = json_model["properties"]
             obj.title = properties["title"]
-            self.set_responsibility(obj, properties["responsible"])
-            self.set_legal(obj, properties["legal"])
+            obj.is_cef = properties["is_cef"]
+            obj.is_coherence_keeping = properties["is_coherence_keeping"]
+            obj.modified = update_action
             obj.geometry.geom = self.create_geometry_from_json(json_model)
+            obj.geometry.modified = update_action
+            obj = self.set_intervention(obj, properties["intervention"], user)
 
-            obj.responsible.save()
             obj.geometry.save()
-            obj.legal.save()
             obj.save()
 
-            obj.users.add(user)
+            obj = self.set_compensation_actions(obj, properties["actions"])
+            obj = self.set_compensation_states(obj, properties["before_states"], obj.before_states)
+            obj = self.set_compensation_states(obj, properties["after_states"], obj.after_states)
+            obj = self.set_deadlines(obj, properties["deadlines"])
+
+            obj.log.add(update_action)
 
             celery_update_parcels.delay(obj.geometry.id)
 
diff --git a/api/utils/serializer/v1/intervention.py b/api/utils/serializer/v1/intervention.py
index 1b91a6cb..34fb75c5 100644
--- a/api/utils/serializer/v1/intervention.py
+++ b/api/utils/serializer/v1/intervention.py
@@ -9,16 +9,20 @@ from django.db import transaction
 from django.db.models import QuerySet
 
 from api.utils.serializer.v1.serializer import AbstractModelAPISerializerV1, \
-    ResponsibilityAPISerializerV1Mixin, LegalAPISerializerV1Mixin
+    ResponsibilityAPISerializerV1Mixin, LegalAPISerializerV1Mixin, DeductableAPISerializerV1Mixin
 from codelist.settings import CODELIST_CONSERVATION_OFFICE_ID, CODELIST_REGISTRATION_OFFICE_ID, \
     CODELIST_PROCESS_TYPE_ID, CODELIST_LAW_ID
+from compensation.models import Payment
 from intervention.models import Intervention, Responsibility, Legal
 from konova.models import Geometry
 from konova.tasks import celery_update_parcels
 from user.models import UserActionLogEntry
 
 
-class InterventionAPISerializerV1(AbstractModelAPISerializerV1, ResponsibilityAPISerializerV1Mixin, LegalAPISerializerV1Mixin):
+class InterventionAPISerializerV1(AbstractModelAPISerializerV1,
+                                  ResponsibilityAPISerializerV1Mixin,
+                                  LegalAPISerializerV1Mixin,
+                                  DeductableAPISerializerV1Mixin):
     model = Intervention
 
     def compensations_to_json(self, qs: QuerySet):
@@ -119,6 +123,58 @@ class InterventionAPISerializerV1(AbstractModelAPISerializerV1, ResponsibilityAP
         obj.responsible.handler = responsibility_data["handler"]
         return obj
 
+    def set_payments(self, obj, payment_data):
+        """ Sets the linked Payment data according to the given payment_data
+
+
+        Args:
+            obj (Compensation): The Compensation object
+            payment_data (dict): The posted payment_data
+
+        Returns:
+            obj (intervention)
+        """
+        payments = []
+        for entry in payment_data:
+            due_on = entry["due_on"]
+            amount = float(entry["amount"])
+            comment = entry["comment"]
+
+            # Check on validity
+            if amount <= 0:
+                raise ValueError("Payment amount must be > 0")
+
+            no_due_on = due_on is None or len(due_on) == 0
+            no_comment = comment is None or len(comment) == 0
+
+            if no_due_on and no_comment:
+                raise ValueError("If no due_on can be provided, you need to explain why using the comment")
+
+            # If this exact data is already existing, we do not create it new. Instead put it's id in the list of
+            # entries, we will use to set the new actions
+            pre_existing_payment = obj.payments.filter(
+                amount=amount,
+                due_on=due_on,
+                comment=comment,
+            ).exclude(
+                id__in=payments
+            ).first()
+            if pre_existing_payment is not None:
+                payments.append(pre_existing_payment.id)
+            else:
+                # Create and add id to list
+                new_payment = Payment.objects.create(
+                    amount=amount,
+                    due_on=due_on,
+                    comment=comment,
+                )
+                payments.append(new_payment.id)
+        payments = Payment.objects.filter(
+            id__in=payments
+        )
+        obj.payments.set(payments)
+        return obj
+
     def create_model_from_json(self, json_model, user):
         """ Creates a new entry for the model based on the contents of json_model
 
@@ -163,21 +219,25 @@ class InterventionAPISerializerV1(AbstractModelAPISerializerV1, ResponsibilityAP
             created_id (str): The id of the newly created Intervention entry
         """
         with transaction.atomic():
+            update_action = UserActionLogEntry.get_edited_action(user, "API update")
             obj = self.get_obj_from_db(id, user)
 
             # Fill in data to objects
             properties = json_model["properties"]
             obj.title = properties["title"]
+            obj.modified = update_action
             self.set_responsibility(obj, properties["responsible"])
             self.set_legal(obj, properties["legal"])
+            self.set_payments(obj, properties["payments"])
             obj.geometry.geom = self.create_geometry_from_json(json_model)
+            obj.geometry.modified = update_action
 
             obj.responsible.save()
             obj.geometry.save()
             obj.legal.save()
             obj.save()
 
-            obj.users.add(user)
+            obj.log.add(update_action)
 
             celery_update_parcels.delay(obj.geometry.id)
 
diff --git a/api/utils/serializer/v1/serializer.py b/api/utils/serializer/v1/serializer.py
index f60428b7..af3fa96f 100644
--- a/api/utils/serializer/v1/serializer.py
+++ b/api/utils/serializer/v1/serializer.py
@@ -189,32 +189,36 @@ class AbstractCompensationAPISerializerV1Mixin:
         Returns:
             obj (Compensation)
         """
-        found_deadlines = []
+        deadlines = []
         for entry in deadline_data:
             deadline_type = entry["type"]
             date = entry["date"]
             comment = entry["comment"]
 
+            # Check on validity
             if deadline_type not in DeadlineType:
                 raise ValueError(f"Invalid deadline type. Choices are {DeadlineType.values}")
 
-            pre_existing_deadlines = obj.deadlines.filter(
+            # If this exact data is already existing, we do not create it new. Instead put it's id in the list of
+            # entries, we will use to set the new actions
+            pre_existing_deadline = obj.deadlines.filter(
                 type=deadline_type,
                 date=date,
                 comment=comment,
             ).exclude(
-                id__in=found_deadlines
-            )
-            if pre_existing_deadlines.count() > 0:
-                found_deadlines += pre_existing_deadlines.values_list("id", flat=True)
+                id__in=deadlines
+            ).first()
+            if pre_existing_deadline is not None:
+                deadlines.append(pre_existing_deadline.id)
             else:
-                # Create!
+                # Create and add id to list
                 new_deadline = Deadline.objects.create(
                     type=deadline_type,
                     date=date,
                     comment=comment,
                 )
-                obj.deadlines.add(new_deadline)
+                deadlines.append(new_deadline.id)
+        obj.deadlines.set(deadlines)
         return obj
 
     def set_compensation_states(self, obj, states_data, states_manager):
@@ -229,27 +233,34 @@ class AbstractCompensationAPISerializerV1Mixin:
         Returns:
             obj (Compensation)
         """
-        found_states = []
+        states = []
         for entry in states_data:
             biotope_type = entry["biotope"]
             surface = float(entry["surface"])
+
+            # Check on validity
             if surface <= 0:
                 raise ValueError("State surfaces must be > 0")
-            pre_existing_states = states_manager.filter(
+
+            # If this exact data is already existing, we do not create it new. Instead put it's id in the list of
+            # entries, we will use to set the new actions
+            pre_existing_state = states_manager.filter(
                 biotope_type__atom_id=biotope_type,
                 surface=surface,
             ).exclude(
-                id__in=found_states
-            )
-            if pre_existing_states.count() > 0:
-                found_states += pre_existing_states.values_list("id", flat=True)
+                id__in=states
+            ).first()
+            if pre_existing_state is not None:
+                states.append(pre_existing_state.id)
             else:
-                # Create!
+                # Create and add id to list
                 new_state = CompensationState.objects.create(
                     biotope_type=self.konova_code_from_json(biotope_type, CODELIST_BIOTOPES_ID),
                     surface=surface
                 )
-                states_manager.add(new_state)
+                states.append(new_state.id)
+
+        states_manager.set(states)
         return obj
 
     def set_compensation_actions(self, obj, actions_data):
@@ -263,36 +274,41 @@ class AbstractCompensationAPISerializerV1Mixin:
         Returns:
             obj (Compensation)
         """
-        found_actions = []
+        actions = []
         for entry in actions_data:
             action = entry["action"]
             amount = float(entry["amount"])
             unit = entry["unit"]
             comment = entry["comment"]
 
+            # Check on validity
             if amount <= 0:
                 raise ValueError("Action amount must be > 0")
             if unit not in UnitChoices:
                 raise ValueError(f"Invalid unit. Choices are {UnitChoices.values}")
-            pre_existing_actions = obj.actions.filter(
+
+            # If this exact data is already existing, we do not create it new. Instead put it's id in the list of
+            # entries, we will use to set the new actions
+            pre_existing_action = obj.actions.filter(
                 action_type__atom_id=action,
                 amount=amount,
                 unit=unit,
                 comment=comment,
             ).exclude(
-                id__in=found_actions
-            )
-            if pre_existing_actions.count() > 0:
-                found_actions += pre_existing_actions.values_list("id", flat=True)
+                id__in=actions
+            ).first()
+            if pre_existing_action is not None:
+                actions.append(pre_existing_action.id)
             else:
-                # Create!
+                # Create and add id to list
                 new_action = CompensationAction.objects.create(
                     action_type=self.konova_code_from_json(action, CODELIST_COMPENSATION_ACTION_ID),
                     amount=amount,
                     unit=unit,
                     comment=comment,
                 )
-                obj.actions.add(new_action)
+                actions.append(new_action.id)
+        obj.actions.set(actions)
         return obj
 
     def compensation_state_to_json(self, qs: QuerySet):