diff --git a/uncloud_pay/models.py b/uncloud_pay/models.py
index 1294a54..68016a9 100644
--- a/uncloud_pay/models.py
+++ b/uncloud_pay/models.py
@@ -521,9 +521,8 @@ class Bill(models.Model):
         bill_records = []
         orders = Order.objects.filter(bill=self)
         for order in orders:
-            for order_record in order.records:
-                bill_record = BillRecord(self, order_record)
-                bill_records.append(bill_record)
+            bill_record = BillRecord(self, order)
+            bill_records.append(bill_record)
 
         return bill_records
 
@@ -710,18 +709,18 @@ class Bill(models.Model):
 
 class BillRecord():
     """
-    Entry of a bill, dynamically generated from order records.
+    Entry of a bill, dynamically generated from an order.
     """
 
-    def __init__(self, bill, order_record):
+    def __init__(self, bill, order):
         self.bill = bill
-        self.order = order_record.order
-        self.recurring_price = order_record.recurring_price
-        self.recurring_period = order_record.recurring_period
-        self.description = order_record.description
+        self.order = order
+        self.recurring_price = order.recurring_price
+        self.recurring_period = order.recurring_period
+        self.description = order.description
 
         if self.order.starting_date >= self.bill.starting_date:
-            self.one_time_price = order_record.one_time_price
+            self.one_time_price = order.one_time_price
         else:
             self.one_time_price = 0
 
@@ -779,7 +778,7 @@ class BillRecord():
             return 0
         else:
             raise Exception('Unsupported recurring period: {}.'.
-                    format(record.recurring_period))
+                    format(self.order.recurring_period))
 
     @property
     def vat_rate(self):