diff --git a/uncloud/uncloud_pay/models.py b/uncloud/uncloud_pay/models.py
index e257b9e..9cbeb48 100644
--- a/uncloud/uncloud_pay/models.py
+++ b/uncloud/uncloud_pay/models.py
@@ -38,12 +38,7 @@ class Bill(models.Model):
         orders = Order.objects.filter(bill=self)
         for order in orders:
             for order_record in order.records:
-                bill_record = BillRecord(
-                        self,
-                        order_record.setup_fee,
-                        order_record.recurring_price,
-                        order_record.recurring_period,
-                        order_record.description)
+                bill_record = BillRecord(order_record)
                 bill_records.append(bill_record)
 
         return bill_records
@@ -53,12 +48,12 @@ class Bill(models.Model):
         return reduce(lambda acc, record: acc + record.amount(), self.records, 0)
 
 class BillRecord():
-    def __init__(self, bill, setup_fee, recurring_price, recurring_period, description):
-        self.bill = bill
-        self.setup_fee = setup_fee
-        self.recurring_price = recurring_price
-        self.recurring_period = recurring_period
-        self.description = description
+    def __init__(self, order_record):
+        self.order = order_record.order.uuid
+        self.setup_fee = order_record.setup_fee
+        self.recurring_price = order_record.recurring_price
+        self.recurring_period = order_record.recurring_period
+        self.description = order_record.description
 
     def amount(self):
         # TODO: Billing logic here!
diff --git a/uncloud/uncloud_pay/serializers.py b/uncloud/uncloud_pay/serializers.py
index 976ab6b..e3ac0eb 100644
--- a/uncloud/uncloud_pay/serializers.py
+++ b/uncloud/uncloud_pay/serializers.py
@@ -9,6 +9,7 @@ from uncloud_vm.models import VMProduct
 
 # TODO: remove magic numbers for decimal fields
 class BillRecordSerializer(serializers.Serializer):
+    order = serializers.CharField()
     description = serializers.CharField()
     recurring_period = serializers.CharField()
     recurring_price = serializers.DecimalField(max_digits=10, decimal_places=2)