diff --git a/lemarche/api/tenders/serializers.py b/lemarche/api/tenders/serializers.py
index a421fe724..72b6d6ce7 100644
--- a/lemarche/api/tenders/serializers.py
+++ b/lemarche/api/tenders/serializers.py
@@ -3,6 +3,7 @@
 from lemarche.perimeters.models import Perimeter
 from lemarche.sectors.models import Sector
 from lemarche.tenders.models import Tender
+from lemarche.users import constants as user_constants
 
 
 class TenderSerializer(serializers.ModelSerializer):
@@ -14,6 +15,13 @@ class TenderSerializer(serializers.ModelSerializer):
         queryset=Perimeter.objects.all(), slug_field="slug", allow_null=True, required=False
     )
     extra_data = serializers.JSONField(required=False)
+    # non-model fields
+    contact_kind = serializers.ChoiceField(
+        choices=user_constants.KIND_CHOICES, allow_blank=True, write_only=True, required=False
+    )
+    contact_buyer_kind_detail = serializers.ChoiceField(
+        choices=user_constants.BUYER_KIND_DETAIL_CHOICES, allow_blank=True, write_only=True, required=False
+    )
 
     class Meta:
         model = Tender
@@ -47,4 +55,7 @@ class Meta:
             "deadline_date",
             # extra data
             "extra_data",
+            # non-model fields
+            "contact_kind",
+            "contact_buyer_kind_detail",
         ]
diff --git a/lemarche/api/tenders/views.py b/lemarche/api/tenders/views.py
index e6bc361e9..5cd5ceaca 100644
--- a/lemarche/api/tenders/views.py
+++ b/lemarche/api/tenders/views.py
@@ -26,17 +26,28 @@ def create(self, request, *args, **kwargs):
         return super().create(request, args, kwargs)
 
     def perform_create(self, serializer: TenderSerializer):
+        """
+        - set Tender source
+        - set Tender author (create user if it doesn't exist)
+        - pop non-model fields
+        - create Tender !
+        """
         source = (
             tender_constants.SOURCE_TALLY
             if serializer.validated_data.get("extra_data", {}).get("source") == tender_constants.SOURCE_TALLY
             else tender_constants.SOURCE_API
         )
+        # get Tender author
         user = get_or_create_user_from_anonymous_content(
             serializer.validated_data,
             source=user_constants.SOURCE_TALLY_FORM
             if source == tender_constants.SOURCE_TALLY
             else user_constants.SOURCE_SIGNUP_FORM,
         )
+        # pop non-model fields
+        serializer.validated_data.pop("contact_kind", None)
+        serializer.validated_data.pop("contact_buyer_kind_detail", None)
+        # create Tender
         serializer.save(
             author=user,
             status=tender_constants.STATUS_PUBLISHED,