diff --git a/invoice/models.py b/invoice/models.py
index ed0e675..94ca333 100644
--- a/invoice/models.py
+++ b/invoice/models.py
@@ -13,12 +13,12 @@ class Invoice(models.Model):
     is_archived = models.BooleanField(default=False)
 
     @property
-    def invoice_total_without_tax(self):
-        items = Item.objects.filter(invoice=self.pk)
+    def invoice_total_with_tax(self):
+        items = self.items.all()
         total = 0
         for item in items:
             total += item.item_total
-        return total
+        return total + (total * self.project.client.address.tax_type.percentage / 100)
 
     def __str__(self):
         return self.invoice_id
diff --git a/invoice/serializers.py b/invoice/serializers.py
index d726e22..f2e8159 100644
--- a/invoice/serializers.py
+++ b/invoice/serializers.py
@@ -17,4 +17,4 @@ class InvoiceSerializer(WritableNestedModelSerializer):
     class Meta:
         model = Invoice
         fields = ['id', 'title', 'project', 'invoice_id', 'raised_date', 'due_date', 'paid_date', 'is_archived',
-                  'invoice_total_without_tax', 'items']
+                  'invoice_total_with_tax', 'items']