diff --git a/dojo/api_v2/views.py b/dojo/api_v2/views.py
index 9676983684d..384fc91c973 100644
--- a/dojo/api_v2/views.py
+++ b/dojo/api_v2/views.py
@@ -503,6 +503,10 @@ def notes(self, request, pk=None):
                     new_note.errors, status=status.HTTP_400_BAD_REQUEST,
                 )
 
+            notes = engagement.notes.filter(note_type=note_type).first()
+            if notes and note_type and note_type.is_single:
+                return Response("Only one instance of this note_type allowed on an engagement.", status=status.HTTP_400_BAD_REQUEST)
+
             author = request.user
             note = Notes(
                 entry=entry,
@@ -1078,6 +1082,11 @@ def notes(self, request, pk=None):
                     new_note.errors, status=status.HTTP_400_BAD_REQUEST,
                 )
 
+            if finding.notes:
+                notes = finding.notes.filter(note_type=note_type).first()
+                if notes and note_type and note_type.is_single:
+                    return Response("Only one instance of this note_type allowed on a finding.", status=status.HTTP_400_BAD_REQUEST)
+
             author = request.user
             note = Notes(
                 entry=entry,
@@ -2131,6 +2140,10 @@ def notes(self, request, pk=None):
                     new_note.errors, status=status.HTTP_400_BAD_REQUEST,
                 )
 
+            notes = test.notes.filter(note_type=note_type).first()
+            if notes and note_type and note_type.is_single:
+                return Response("Only one instance of this note_type allowed on a test.", status=status.HTTP_400_BAD_REQUEST)
+
             author = request.user
             note = Notes(
                 entry=entry,