diff --git a/accounting/converters.py b/accounting/converters.py
index dbecbd6..84d7184 100644
--- a/accounting/converters.py
+++ b/accounting/converters.py
@@ -193,7 +193,7 @@ class TransactionConverter:
             Transaction: The account.
         """
         try:
-            return Transaction.objects.get(sn=value)
+            return Transaction.objects.get(pk=value)
         except Transaction.DoesNotExist:
             raise ValueError
 
diff --git a/accounting/management/commands/accounting_sample.py b/accounting/management/commands/accounting_sample.py
index 4d6929d..8ecfaaf 100644
--- a/accounting/management/commands/accounting_sample.py
+++ b/accounting/management/commands/accounting_sample.py
@@ -50,7 +50,7 @@ class Command(BaseCommand):
         if input().lower() not in ("y", "yes"):
             return
 
-        user = User(sn=923153018, login_id="imacat",
+        user = User(pk=923153018, login_id="imacat",
                     password="5486b64881adaf7bc1485cc26e57e51e", name="依瑪貓",
                     is_disabled=False, is_deleted=False)
         user.created_by = user
diff --git a/accounting/utils.py b/accounting/utils.py
index 39dad61..594c31d 100644
--- a/accounting/utils.py
+++ b/accounting/utils.py
@@ -134,7 +134,7 @@ class Populator:
                 code = str(code)
             parent = None if len(code) == 1\
                 else Account.objects.get(code=code[:-1])
-            Account(sn=new_id(Account), parent=parent, code=code,
+            Account(pk=new_id(Account), parent=parent, code=code,
                     title_zh_hant=data[1], title_en=data[2],
                     title_zh_hans=data[3],
                     created_by=self.user, updated_by=self.user).save()
@@ -153,7 +153,7 @@ class Populator:
         if isinstance(date, int):
             date = timezone.localdate() + timezone.timedelta(days=date)
         order = Transaction.objects.filter(date=date).count() + 1
-        transaction = Transaction(sn=new_id(Transaction), date=date, ord=order,
+        transaction = Transaction(pk=new_id(Transaction), date=date, ord=order,
                                   created_by=self.user, updated_by=self.user)
         transaction.save()
         order = 1
@@ -163,7 +163,7 @@ class Populator:
                 account = Account.objects.get(code=account)
             elif isinstance(account, int):
                 account = Account.objects.get(code=str(account))
-            transaction.record_set.create(sn=new_id(Record), is_credit=False,
+            transaction.record_set.create(pk=new_id(Record), is_credit=False,
                                           ord=order, account=account,
                                           summary=data[1], amount=data[2],
                                           created_by=self.user,
@@ -176,7 +176,7 @@ class Populator:
                 account = Account.objects.get(code=account)
             elif isinstance(account, int):
                 account = Account.objects.get(code=str(account))
-            transaction.record_set.create(sn=new_id(Record), is_credit=True,
+            transaction.record_set.create(pk=new_id(Record), is_credit=True,
                                           ord=order, account=account,
                                           summary=data[1], amount=data[2],
                                           created_by=self.user,