diff --git a/network_inventory/inventory/models/backup.py b/network_inventory/inventory/models/backup.py
index 5b0ae06..f9bc827 100644
--- a/network_inventory/inventory/models/backup.py
+++ b/network_inventory/inventory/models/backup.py
@@ -30,6 +30,10 @@ class Backup(models.Model):
     def __str__(self):
         return str(self.name)
 
+    @property
+    def customer(self):
+        return self.computer.customer
+
 
 class TargetDevice(models.Model):
     device = models.ForeignKey(Computer, models.SET_NULL, blank=True,
diff --git a/network_inventory/inventory/models/warranty.py b/network_inventory/inventory/models/warranty.py
index c9db274..f9ad635 100644
--- a/network_inventory/inventory/models/warranty.py
+++ b/network_inventory/inventory/models/warranty.py
@@ -23,3 +23,7 @@ class Warranty(models.Model):
 
     class Meta:
         verbose_name_plural = "Warranties"
+
+    @property
+    def customer(self):
+        return self.device.customer