diff --git a/kmymoney/widgets/CMakeLists.txt b/kmymoney/widgets/CMakeLists.txt
index 09a80f5d9..99a78776b 100644
--- a/kmymoney/widgets/CMakeLists.txt
+++ b/kmymoney/widgets/CMakeLists.txt
@@ -1,260 +1,266 @@
 
 ########### create links ###############
 set(kmymoney_STAT_HEADERS
   kaccounttemplateselector.h kguiutils.h
   kmymoneyaccountcombo.h kmymoneyaccountcompletion.h
   kmymoneyaccountselector.h
   kmymoneycategory.h
   kmymoneycombo.h kmymoneymvccombo.h kmymoneycompletion.h
   kmymoneycurrencyselector.h  kmymoneydateinput.h
   kmymoneylineedit.h kmymoneyselector.h
   kmymoneytitlelabel.h register.h registeritem.h groupmarker.h fancydategroupmarker.h
   scheduledtransaction.h selectedtransaction.h selectedtransactions.h stdtransactiondownloaded.h
   stdtransactionmatched.h transactioneditorcontainer.h
   transactionform.h transaction.h investtransaction.h stdtransaction.h
   transactionsortoption.h
   kmymoneyvalidationfeedback.h
   onlinejobmessagesview.h
   kmymoneydateedit.h
   amountedit.h amountvalidator.h creditdebithelper.h
   )
 
 ########### Shared widget library ###########
 set(kmm_widgets_sources
   kmymoneydateinput.cpp
   kmymoneyvalidationfeedback.cpp
   styleditemdelegateforwarder.cpp
   kmymoneylineedit.cpp
   kmymoneytextedit.cpp
   kmymoneytextedithighlighter.cpp
   kmymoneymvccombo.cpp
   kmymoneygeneralcombo.cpp
   kmymoneyactivitycombo.cpp
   kmymoneycashflowcombo.cpp
   kmymoneyfrequencycombo.cpp
   kmymoneyoccurrencecombo.cpp
   kmymoneyoccurrenceperiodcombo.cpp
   kmymoneypayeecombo.cpp
   kmymoneyperiodcombo.cpp
   kmymoneyreconcilecombo.cpp
   kmymoneytagcombo.cpp
   kmymoneyaccountselector.cpp
   ktagcontainer.cpp
   ktaglabel.cpp
   kmymoneyselector.cpp
   kmymoneycalculator.cpp
   ktreewidgetfilterlinewidget.cpp
   kguiutils.cpp
   onlinejobmessagesview.cpp
   kmymoneydateedit.cpp
   kmymoneymoneyvalidator.cpp
   amountedit.cpp
   amountvalidator.cpp
   creditdebithelper.cpp
   daterangedlg.cpp
   ktransactionfilter.cpp
   kmymoneyaccounttreeview.cpp
   accountsviewproxymodel.cpp
   budgetviewproxymodel.cpp
   kmymoneyviewbase.cpp
   kmymoneyaccountsviewbase.cpp
   )
 
 set(nationalAccountWidget_SOURCES
   ./payeeidentifier/nationalaccount/nationalaccountedit.cpp
   ./payeeidentifier/nationalaccount/nationalaccountdelegate.cpp
 )
 
 set(nationalAccountWidget_HEADERS
   ./payeeidentifier/nationalaccount/nationalaccountdelegate.h
   ./payeeidentifier/nationalaccount/nationalaccountedit.h
 )
 
 set(IBANBICWidget_SOURCES
   ./payeeidentifier/ibanbic/kibanlineedit.cpp
   ./payeeidentifier/ibanbic/kbicedit.cpp
   ./payeeidentifier/ibanbic/ibanvalidator.cpp
   ./payeeidentifier/ibanbic/bicvalidator.cpp
   ./payeeidentifier/ibanbic/ibanbicitemdelegate.cpp
   ./payeeidentifier/ibanbic/ibanbicitemedit.cpp
 )
 
 set(IBANBICWidget_HEADERS
   ./payeeidentifier/ibanbic/kibanlineedit.h
   ./payeeidentifier/ibanbic/kbicedit.h
   ./payeeidentifier/ibanbic/ibanvalidator.h
   ./payeeidentifier/ibanbic/bicvalidator.h
   ./payeeidentifier/ibanbic/ibanbicitemdelegate.h
 )
 
 list(APPEND kmm_widgets_sources ${nationalAccountWidget_SOURCES})
 list(APPEND kmymoney_STAT_HEADERS ${nationalAccountWidget_HEADERS})
 
 list(APPEND kmm_widgets_sources ${IBANBICWidget_SOURCES})
 list(APPEND kmymoney_STAT_HEADERS ${IBANBICWidget_HEADERS})
 
 ki18n_wrap_ui(kmm_widgets_sources
   kmymoneyvalidationfeedback.ui
   onlinejobmessagesview.ui
   daterangedlg.ui
   ktransactionfilter.ui
   ./payeeidentifier/nationalaccount/nationalaccountedit.ui
   ./payeeidentifier/ibanbic/ibanbicitemedit.ui
 )
 
 add_library(kmm_widgets SHARED ${kmm_widgets_sources})
 target_link_libraries(kmm_widgets PUBLIC
   kmm_settings
   KF5::TextWidgets
   KF5::KIOWidgets
   KF5::Completion
   KF5::Notifications
   KF5::ItemViews
   KF5::I18n
   Qt5::Gui
   Qt5::Core
   Alkimia::alkimia
   kmm_mymoney
   kmm_models
   kmm_plugin
 )
 
 set_target_properties(kmm_widgets PROPERTIES
   VERSION ${PROJECT_VERSION} SOVERSION ${PROJECT_VERSION_MAJOR}
   COMPILE_FLAGS "-DKMM_BUILD_WIDGETS_LIB"
 )
 
 generate_export_header(kmm_widgets)
 
 install(TARGETS kmm_widgets ${INSTALL_TARGETS_DEFAULT_ARGS} )
 
 ########### Basic Widget Library (kmymoney_base) STATIC #################
 
 # Common sources for libkmymoney.so and libwidgets.a that do not
 # contain the KMM_DESIGNER flag
 set(_uncritial_common_sources
   kmymoneyaccountcombo.cpp
   kmymoneycombo.cpp
   kmymoneycompletion.cpp
   kmymoneytitlelabel.cpp
   kmymoneydateedit.cpp
   kpricetreeitem.cpp
   registeritem.cpp
   registerfilter.cpp
   scheduledtransaction.cpp
   selectedtransaction.cpp
   selectedtransactions.cpp
   stdtransactiondownloaded.cpp
   stdtransactionmatched.cpp
   transactionform.cpp
   tabbar.cpp
   transactionformitemdelegate.cpp
   transactionsortoption.cpp
   )
 
 # sources that contain the KMM_DESIGNER flag
 set (_critial_common_sources
   kaccounttemplateselector.cpp
   kmymoneycurrencyselector.cpp
   kmymoneyaccountcompletion.cpp
   kmymoneycategory.cpp
   groupmarker.cpp
   groupmarkers.cpp
   fancydategroupmarker.cpp
   fancydategroupmarkers.cpp
   register.cpp
   itemptrvector.cpp
   qwidgetcontainer.cpp
   registeritemdelegate.cpp
   transaction.cpp
   stdtransaction.cpp
   investtransaction.cpp
   transactioneditorcontainer.cpp
   )
 
 
 set (kmymoney_base_UI
   transactionsortoption.ui kaccounttemplateselector.ui
   )
 
 ki18n_wrap_ui(kmymoney_base_ui_srcs ${kmymoney_base_UI})
 set(_uncritial_common_sources ${_uncritial_common_sources}
   ${kmymoney_base_ui_srcs})
 
 # in order to use add_dependencies, we need to add this custom target
 # for all generated header files.
 # (see http://www.vtk.org/Wiki/CMake_FAQ#How_can_I_add_a_dependency_to_a_source_file_which_is_generated_in_a_subdirectory.3F )
 add_custom_target(generate_base_ui_srcs DEPENDS
   ${kmymoney_base_ui_srcs})
 
 # We can compile the uncritical sources without KMM_DESIGNER flags
 add_library(kmymoney_base STATIC ${_uncritial_common_sources})
 # TODO: fix dependencies
 target_link_libraries(kmymoney_base KF5::XmlGui KF5::TextWidgets KF5::IconThemes KF5::I18n KF5::ConfigWidgets KF5::ConfigCore KF5::Completion KF5::Service Qt5::Gui Qt5::Widgets Qt5::Xml kmm_settings Alkimia::alkimia)
 
 add_dependencies(kmymoney_base kmm_settings)
 
 ########### QtDesigner Widget Library (kmymoneywidgets) #################
 # we never link against this library,
 # but it is needed for uic and QtDesigner
 if( USE_QT_DESIGNER )
   set(kmymoneywidgets_PART_SRCS
       ${CMAKE_CURRENT_BINARY_DIR}/kmymoneywidgets.cpp)
 
   kde4_add_widget_files(kmymoneywidgets_PART_SRCS kmymoney.widgets)
 
   set(kmymoneywidgets_PART_SRCS
     ${_critial_common_sources}
     ${kmymoneywidgets_PART_SRCS})
 
   add_library(kmymoneywidgets MODULE ${kmymoneywidgets_PART_SRCS})
 
   include_directories( ${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR} )
 
   # The option -DKMM_DESIGNER will leave away any code that breaks uic.
   set_target_properties(kmymoneywidgets PROPERTIES
     COMPILE_FLAGS "-DKMM_DESIGNER")
 
   # The qt-designer widget library shouldn't need to link against the
   # dialogs and converter libraries.  If a widget references something
   # from one of these libraries it is most likely due to code that needs
   # to be excluded with a KMM_DESIGNER ifndef.
   target_link_libraries(kmymoneywidgets kmymoney_base kmm_mymoney kmymoney_common kmm_settings models)
 
   install(TARGETS kmymoneywidgets DESTINATION ${QT_PLUGINS_DIR}/designer )
 endif( USE_QT_DESIGNER )
 
 ########### Widget Library (widgets) STATIC #################
 
 set(libwidgets_a_SOURCES
   ${_critial_common_sources}
   kmymoneybriefschedule.cpp
   registersearchline.cpp
   transactioneditorcontainer.cpp
   )
 
 set(libwidgets_a_UI
   kmymoneybriefschedule.ui
   )
 
 # using uic on the above UI files DEPENDS on libkmymoney.so. If uic
 # does not find libkmymoney.so, gcc will fail compiling
 # kmymoneyreportconfigtab2decl.cpp and throw errors like "invalid use
 # of undefined type `struct KMyMoneyGeneralCombo'"
 
 
 ki18n_wrap_ui(widgets_ui_srcs ${libwidgets_a_UI})
 add_custom_target(generate_widgets_ui_srcs DEPENDS ${widgets_ui_srcs})
 
 add_library(widgets STATIC
   ${libwidgets_a_SOURCES}
   ${widgets_ui_srcs}
   )
 target_link_libraries(widgets KF5::XmlGui kmymoney_base)
 
 add_dependencies(widgets kmm_settings)
 
 ########### install files ###############
 
 install(FILES ${kmymoney_STAT_HEADERS} ${CMAKE_CURRENT_BINARY_DIR}/kmm_widgets_export.h
   DESTINATION ${INCLUDE_INSTALL_DIR}/kmymoney COMPONENT Devel)
+
+############## tests ####################
+
+if(BUILD_TESTING)
+  add_subdirectory(tests)
+endif()
diff --git a/kmymoney/widgets/amountvalidator.h b/kmymoney/widgets/amountvalidator.h
index 20925df8f..8a32ade5b 100644
--- a/kmymoney/widgets/amountvalidator.h
+++ b/kmymoney/widgets/amountvalidator.h
@@ -1,71 +1,69 @@
 /*
  * Copyright 2016       Thomas Baumgart <tbaumgart@kde.org>
  * Copyright 2017-2018  Łukasz Wojniłowicz <lukasz.wojnilowicz@gmail.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; either version 2 of
  * the License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #ifndef AMOUNTVALIDATOR_H
 #define AMOUNTVALIDATOR_H
 
 #include "kmm_widgets_export.h"
 
 // ----------------------------------------------------------------------------
 // QT Includes
 
 #include <QDoubleValidator>
 
 // ----------------------------------------------------------------------------
 // KDE Includes
 
 // ----------------------------------------------------------------------------
 // Project Includes
 
-#include "mymoneymoney.h"
-
 /**
   * This class is derived from KDoubleValidator and uses
   * the monetary symbols instead of the numeric symbols.
   * Also, it always accepts localized input.
   *
   * @author Thomas Baumgart
   */
 class AmountValidator : public QDoubleValidator
 {
   Q_OBJECT
 
 public:
   /**
     * Constuct a locale-aware KDoubleValidator with default range
     * (whatever QDoubleValidator uses for that) and parent @p
     * parent
     */
   explicit AmountValidator(QObject * parent);
   /**
     * Constuct a locale-aware KDoubleValidator for range [@p bottom,@p
     * top] and a precision of @p digits after the decimal
     * point.
     */
   explicit AmountValidator(double bottom, double top, int decimals,
                          QObject * parent);
   /**
     * Destructs the validator.
     */
   ~AmountValidator();
 
   /** Overloaded for internal reasons. The API is not affected. */
   QValidator::State validate(QString & input, int & pos) const override;
 };
 
 #endif
diff --git a/kmymoney/widgets/tests/CMakeLists.txt b/kmymoney/widgets/tests/CMakeLists.txt
new file mode 100644
index 000000000..a56d13000
--- /dev/null
+++ b/kmymoney/widgets/tests/CMakeLists.txt
@@ -0,0 +1,21 @@
+include(ECMAddTests)
+
+set(testwidgets_SOURCES
+    ../amountvalidator.cpp
+    )
+
+add_library(testwidgets STATIC ${testwidgets_SOURCES})
+target_link_libraries(testwidgets PUBLIC
+    Qt5::Gui
+    Qt5::Core
+)
+
+file(GLOB tests_sources "*-test.cpp")
+ecm_add_tests(${tests_sources}
+  LINK_LIBRARIES
+    Qt5::Gui
+    Qt5::Core
+    Qt5::Test
+    Qt5::Xml
+    testwidgets
+)
diff --git a/kmymoney/widgets/tests/amountvalidator-test.cpp b/kmymoney/widgets/tests/amountvalidator-test.cpp
new file mode 100644
index 000000000..9bcba3c7d
--- /dev/null
+++ b/kmymoney/widgets/tests/amountvalidator-test.cpp
@@ -0,0 +1,116 @@
+/*
+ * Copyright 2019       Thomas Baumgart <tbaumgart@kde.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "amountvalidator-test.h"
+
+#include <QtTest>
+#include <QValidator>
+
+#include <config-kmymoney.h>
+#include "amountvalidator.h"
+
+QTEST_GUILESS_MAIN(AmountValidatorTest)
+
+void AmountValidatorTest::init()
+{
+    defaultLocale = QLocale();
+}
+
+void AmountValidatorTest::cleanup()
+{
+    QLocale::setDefault(defaultLocale);
+}
+
+
+void AmountValidatorTest::setLocale(const QString& name)
+{
+    currentLocale = name;
+}
+
+void AmountValidatorTest::addAcceptableNumber(const QString& testCaseName, const QString& number)
+{
+    const int result = static_cast<int>(QValidator::Acceptable);
+    QString fixedNumber(number);
+    // replace a blank in the test string with a non-breakable-space
+    fixedNumber.replace(" ", "\u00A0");
+    QTest::newRow((QString("%1:%2").arg(currentLocale, testCaseName)).toUtf8()) << currentLocale << fixedNumber << result;
+}
+
+void AmountValidatorTest::addInvalidNumber(const QString& testCaseName, const QString& number)
+{
+    const int result = static_cast<int>(QValidator::Invalid);
+    QString fixedNumber(number);
+    // replace a blank in the test string with a non-breakable-space
+    fixedNumber.replace(" ", "\u00A0");
+    QTest::newRow((QString("%1:%2").arg(currentLocale, testCaseName)).toUtf8()) << currentLocale << fixedNumber << result;
+}
+
+void AmountValidatorTest::testValidator_data()
+{
+    QTest::addColumn<QString>("locale");
+    QTest::addColumn<QString>("inputValue");
+    QTest::addColumn<int>("result");
+
+    setLocale("en_US");
+    addAcceptableNumber("amount w/ thousand and decimal", "1,123.00");
+    addAcceptableNumber("amount no thousand but decimal", "1123.00");
+    addAcceptableNumber("neg. amount no thousand but decimal", "-1123.00");
+    addAcceptableNumber("amount no thousand no decimal", "1123");
+    addAcceptableNumber("amount only fraction", ".00");
+
+    addInvalidNumber("amount w/ thousand and decimal reversed", "1.123,00");
+    addInvalidNumber("neg. amount w/ thousand and decimal reversed", "1.123,00-");
+    addInvalidNumber("amount only fraction reversed", ",00");
+
+    setLocale("sv_FI");
+    addAcceptableNumber("amount w/ thousand and decimal", "1 123,00");
+    addAcceptableNumber("neg. amount w/ thousand and decimal", "-1 123,00");
+    addAcceptableNumber("amount no thousand but decimal", "1123,00");
+    addAcceptableNumber("amount no thousand no decimal", "1123");
+    addAcceptableNumber("amount only fraction", ",00");
+
+    setLocale("de_DE");
+    addAcceptableNumber("amount w/ thousand and decimal", "1.123,00");
+    addAcceptableNumber("amount no thousand but decimal", "1123,00");
+    addAcceptableNumber("amount no thousand no decimal", "1123");
+    addAcceptableNumber("amount only fraction", ",00");
+
+    addInvalidNumber("amount w/ thousand and decimal reversed", "1,123.00");
+    addInvalidNumber("amount only fraction reversed", ".00");
+
+    setLocale("es_PE");
+    addAcceptableNumber("amount w/ thousand and decimal", "1,123.00");
+    addAcceptableNumber("amount no thousand but decimal", "1123.00");
+    addAcceptableNumber("amount no thousand no decimal", "1123");
+    addAcceptableNumber("amount only fraction", ".00");
+
+    addInvalidNumber("amount w/ thousand and decimal reversed", "1.123,00");
+    addInvalidNumber("amount only fraction reversed", ",00");
+}
+
+void AmountValidatorTest::testValidator()
+{
+    QFETCH(QString, locale);
+    QFETCH(QString, inputValue);
+    QFETCH(int, result);
+
+    QLocale::setDefault(locale);
+    AmountValidator m(nullptr);
+    int pos = inputValue.length();
+    // QCOMPARE(m->validate(inputValue, pos), static_cast<QValidator::State>(result));
+    QCOMPARE((int)m.validate(inputValue, pos), result);
+}
diff --git a/kmymoney/widgets/tests/amountvalidator-test.h b/kmymoney/widgets/tests/amountvalidator-test.h
new file mode 100644
index 000000000..de958ca30
--- /dev/null
+++ b/kmymoney/widgets/tests/amountvalidator-test.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2019       Thomas Baumgart <tbaumgart@kde.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef AMOUNTVALIDATORTEST_H
+#define AMOUNTVALIDATORTEST_H
+
+#include <QObject>
+#include <QLocale>
+#include <QString>
+
+class AmountValidator;
+
+class AmountValidatorTest : public QObject
+{
+    Q_OBJECT
+
+protected:
+    QLocale         defaultLocale;
+    QString         currentLocale;
+
+private Q_SLOTS:
+    void init();
+    void cleanup();
+    void testValidator_data();
+    void testValidator();
+
+private:
+    void setLocale(const QString& name);
+    void addAcceptableNumber(const QString& testCaseName, const QString& number);
+    void addInvalidNumber(const QString& testCaseName, const QString& number);
+};
+
+#endif