diff --git a/Sistemas/serializers.py b/Sistemas/serializers.py
index 59ec2aa..56762a3 100644
--- a/Sistemas/serializers.py
+++ b/Sistemas/serializers.py
@@ -2,6 +2,7 @@
 from rest_framework import serializers
 from .models import Device, Sistema, sistemas_por_cliente
 from Clientes.models import Clientes
+from django.db.models import Q
 
 class SistemaPrimaryKeyRelatedField(serializers.PrimaryKeyRelatedField):
     def to_internal_value(self,data):
@@ -33,8 +34,22 @@ class DeviceSerializer(serializers.ModelSerializer):
     #the request context passed throught argument in the view to the serializer
     #given that the macAddres field are read_Only in the beggining of this serialazer
     #we need passing the post data to the creation instance before commited to the DB
-    def create(self, validated_data):        
-        validated_data['macAddress']= self.context['request'].data.get('macAddress')
+    def create(self, validated_data):
+        mac_address = self.context['request'].data.get('macAddress')
+        sistema = validated_data['sistema']
+        client = validated_data['client']
+        
+        existing_devices = Device.objects.filter(
+            Q(sistema=sistema)& Q(client=client)& Q(macAddress=mac_address)
+        )
+        
+        if existing_devices.exists():
+            # A device with the same macAddress already exists for the given sistema and client
+            # Get the number of existing devices and add 1 to create a new suffix
+            suffix = existing_devices.count() + 1
+            mac_address += f'_{suffix}'        
+
+        validated_data['macAddress']= mac_address
         return super().create(validated_data)
 
     def validate(self, data):
diff --git a/Sistemas/views.py b/Sistemas/views.py
index a70877a..9abaa6b 100644
--- a/Sistemas/views.py
+++ b/Sistemas/views.py
@@ -191,6 +191,9 @@ class Sistema_CreateView(CreateView):
 ========================= API Views
 '''
 
+
+
+
 class RegisterDeviceView(APIView):
     permissions_classes = (permissions.AllowAny,)