diff --git a/src/accounting/account/views.py b/src/accounting/account/views.py
index 4054bd9..cf43c50 100644
--- a/src/accounting/account/views.py
+++ b/src/accounting/account/views.py
@@ -27,6 +27,7 @@ from werkzeug.datastructures import ImmutableMultiDict
 from accounting import db
 from accounting.locale import lazy_gettext
 from accounting.models import Account, BaseAccount
+from accounting.utils.flash_errors import flash_form_errors
 from accounting.utils.next_uri import inherit_next, or_next
 from accounting.utils.pagination import Pagination
 from accounting.utils.permission import can_view, has_permission, can_edit
@@ -78,9 +79,7 @@ def add_account() -> redirect:
     """
     form = AccountForm(request.form)
     if not form.validate():
-        for key in form.errors:
-            for error in form.errors[key]:
-                flash(error, "error")
+        flash_form_errors(form)
         session["form"] = urlencode(list(request.form.items()))
         return redirect(inherit_next(url_for("accounting.account.create")))
     account: Account = Account()
@@ -133,9 +132,7 @@ def update_account(account: Account) -> redirect:
     """
     form = AccountForm(request.form)
     if not form.validate():
-        for key in form.errors:
-            for error in form.errors[key]:
-                flash(error, "error")
+        flash_form_errors(form)
         session["form"] = urlencode(list(request.form.items()))
         return redirect(inherit_next(url_for("accounting.account.edit",
                                              account=account)))
diff --git a/src/accounting/currency/views.py b/src/accounting/currency/views.py
index f1323db..11ae10b 100644
--- a/src/accounting/currency/views.py
+++ b/src/accounting/currency/views.py
@@ -27,6 +27,7 @@ from werkzeug.datastructures import ImmutableMultiDict
 from accounting import db
 from accounting.locale import lazy_gettext
 from accounting.models import Currency
+from accounting.utils.flash_errors import flash_form_errors
 from accounting.utils.next_uri import inherit_next, or_next
 from accounting.utils.pagination import Pagination
 from accounting.utils.permission import has_permission, can_view, can_edit
@@ -80,9 +81,7 @@ def add_currency() -> redirect:
     """
     form = CurrencyForm(request.form)
     if not form.validate():
-        for key in form.errors:
-            for error in form.errors[key]:
-                flash(error, "error")
+        flash_form_errors(form)
         session["form"] = urlencode(list(request.form.items()))
         return redirect(inherit_next(url_for("accounting.currency.create")))
     currency: Currency = Currency()
@@ -136,9 +135,7 @@ def update_currency(currency: Currency) -> redirect:
     form = CurrencyForm(request.form)
     form.obj_code = currency.code
     if not form.validate():
-        for key in form.errors:
-            for error in form.errors[key]:
-                flash(error, "error")
+        flash_form_errors(form)
         session["form"] = urlencode(list(request.form.items()))
         return redirect(inherit_next(url_for("accounting.currency.edit",
                                              currency=currency)))
diff --git a/src/accounting/utils/flash_errors.py b/src/accounting/utils/flash_errors.py
new file mode 100644
index 0000000..c699239
--- /dev/null
+++ b/src/accounting/utils/flash_errors.py
@@ -0,0 +1,50 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/1
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The utility to flash all errors from the forms.
+
+This module should not import any other module from the application.
+
+"""
+import typing as t
+
+from flask import flash
+from flask_wtf import FlaskForm
+
+
+def flash_form_errors(form: FlaskForm) -> None:
+    """Flash all errors from a form recursively.
+
+    :param form: The form.
+    :return: None.
+    """
+    __flash_errors(form.errors)
+
+
+def __flash_errors(error: t.Any) -> None:
+    """Flash all errors recursively.
+
+    :param error: The errors.
+    :return: None.
+    """
+    if isinstance(error, dict):
+        for key in error:
+            __flash_errors(error[key])
+    elif isinstance(error, list):
+        for e in error:
+            __flash_errors(e)
+    else:
+        flash(error, "error")