diff --git a/src/contactswidget.cpp b/src/contactswidget.cpp
index 8093fc6..005413f 100644
--- a/src/contactswidget.cpp
+++ b/src/contactswidget.cpp
@@ -5,17 +5,17 @@
 #include "ui_contactswidget.h"
 #include "dialog/contactsdialog.h"
 #include "model/ModelUtils.h"
-#include "utils/utils.h"
+#include "mainwindow.h"
+#include "libwalletqt/AddressBook.h"
 
-#include <QClipboard>
-#include <QDebug>
-#include <QKeyEvent>
+#include <QMessageBox>
 
 ContactsWidget::ContactsWidget(QWidget *parent) :
     QWidget(parent),
     ui(new Ui::ContactsWidget)
 {
     ui->setupUi(this);
+    m_ctx = MainWindow::getContext();
 
     // header context menu
     ui->contacts->header()->setContextMenuPolicy(Qt::CustomContextMenu);
@@ -28,15 +28,16 @@ ContactsWidget::ContactsWidget(QWidget *parent) :
     // context menu
     ui->contacts->setContextMenuPolicy(Qt::CustomContextMenu);
     m_contextMenu = new QMenu(ui->contacts);
-    m_contextMenu->addAction(QIcon(":/assets/images/person.svg"), "New contact", this, &ContactsWidget::newContact);
-
+    m_contextMenu->addAction(QIcon(":/assets/images/person.svg"), "New contact", [this]{
+        this->newContact();
+    });
 
     // row context menu
     m_rowMenu = new QMenu(ui->contacts);
     m_rowMenu->addAction(QIcon(":/assets/images/copy.png"), "Copy address", this, &ContactsWidget::copyAddress);
     m_rowMenu->addAction(QIcon(":/assets/images/copy.png"), "Copy name", this, &ContactsWidget::copyName);
-    m_rowMenu->addAction(QIcon(":/assets/images/appicons/128x128.png"), "Pay to", this, &ContactsWidget::payTo);
-    m_deleteEntryAction = m_rowMenu->addAction("Delete", this, &ContactsWidget::deleteContact);
+    m_rowMenu->addAction("Pay to", this, &ContactsWidget::payTo);
+    m_rowMenu->addAction("Delete", this, &ContactsWidget::deleteContact);
 
     connect(ui->contacts, &QTreeView::customContextMenuRequested, [=](const QPoint & point){
         QModelIndex index = ui->contacts->indexAt(point);
@@ -95,16 +96,44 @@ void ContactsWidget::showHeaderMenu(const QPoint& position)
     m_headerMenu->exec(QCursor::pos());
 }
 
-void ContactsWidget::newContact()
+void ContactsWidget::newContact(QString address, QString name)
 {
-    auto * dialog = new ContactsDialog(this);
+    auto * dialog = new ContactsDialog(this, address, name);
     int ret = dialog->exec();
     if (!ret) return;
 
-    QString address = dialog->getAddress();
-    QString name = dialog->getName();
+    address = dialog->getAddress();
+    name = dialog->getName();
 
-    emit addContact(address, name);
+    bool addressValid = WalletManager::addressValid(address, m_ctx->currentWallet->nettype());
+    if (!addressValid) {
+        QMessageBox::warning(this, "Invalid address", "Invalid address");
+        return;
+    }
+
+    int num_addresses = m_ctx->currentWallet->addressBook()->count();
+    QString address_entry;
+    QString name_entry;
+    for (int i=0; i<num_addresses; i++) {
+        m_ctx->currentWallet->addressBook()->getRow(i, [&address_entry, &name_entry](const AddressBookInfo &entry){
+            address_entry = entry.address();
+            name_entry = entry.description();
+        });
+
+        if (address == address_entry) {
+            QMessageBox::warning(this, "Unable to add contact", "Duplicate address");
+            ui->contacts->setCurrentIndex(m_model->index(i,0)); // Highlight duplicate address
+            return;
+        }
+        if (name == name_entry) {
+            QMessageBox::warning(this, "Unable to add contact", "Duplicate label");
+            this->newContact(address, name);
+            return;
+        }
+    }
+
+    m_ctx->currentWallet->addressBook()->addRow(address, "", name);
+    m_ctx->storeWallet();
 }
 
 void ContactsWidget::deleteContact()
diff --git a/src/contactswidget.h b/src/contactswidget.h
index 3859d15..9d76bd5 100644
--- a/src/contactswidget.h
+++ b/src/contactswidget.h
@@ -6,6 +6,7 @@
 
 #include "model/AddressBookModel.h"
 #include "model/AddressBookProxyModel.h"
+#include "appcontext.h"
 
 #include <QWidget>
 #include <QMenu>
@@ -21,29 +22,28 @@ class ContactsWidget : public QWidget
 public:
     explicit ContactsWidget(QWidget *parent = nullptr);
     void setModel(AddressBookModel * model);
-    ~ContactsWidget();
+    ~ContactsWidget() override;
 
 public slots:
     void copyAddress();
     void copyName();
     void payTo();
-    void newContact();
+    void newContact(QString address = "", QString name = "");
     void deleteContact();
     void setShowFullAddresses(bool show);
     void setSearchFilter(const QString &filter);
 
 signals:
-    void addContact(QString &address, QString &name);
     void fillAddress(QString &address);
 
 private slots:
-    void showHeaderMenu(const QPoint& position);
+    void showHeaderMenu(const QPoint &position);
 
 private:
     Ui::ContactsWidget *ui;
+    AppContext *m_ctx;
 
     QAction *m_showFullAddressesAction;
-    QAction *m_deleteEntryAction;
     QMenu *m_rowMenu;
     QMenu *m_contextMenu;
     QMenu *m_headerMenu;
diff --git a/src/dialog/contactsdialog.cpp b/src/dialog/contactsdialog.cpp
index bf0e207..0ef59a4 100644
--- a/src/dialog/contactsdialog.cpp
+++ b/src/dialog/contactsdialog.cpp
@@ -4,13 +4,19 @@
 #include "ui_contactsdialog.h"
 #include "contactsdialog.h"
 
-ContactsDialog::ContactsDialog(QWidget *parent)
+ContactsDialog::ContactsDialog(QWidget *parent, const QString &address, const QString &name)
     : QDialog(parent)
     , ui(new Ui::ContactsDialog)
 {
     ui->setupUi(this);
     setMinimumWidth(400);
 
+    ui->lineEdit_address->setText(address);
+    ui->lineEdit_name->setText(name);
+    if (!name.isEmpty()) {
+        ui->lineEdit_name->setFocus();
+    }
+
     connect(ui->buttonBox, &QDialogButtonBox::accepted, [&](){
         m_address = ui->lineEdit_address->text();
         m_name = ui->lineEdit_name->text();
diff --git a/src/dialog/contactsdialog.h b/src/dialog/contactsdialog.h
index 1bb231e..2aa9ab1 100644
--- a/src/dialog/contactsdialog.h
+++ b/src/dialog/contactsdialog.h
@@ -15,7 +15,7 @@ class ContactsDialog : public QDialog
     Q_OBJECT
 
 public:
-    explicit ContactsDialog(QWidget *parent = nullptr);
+    explicit ContactsDialog(QWidget *parent = nullptr, const QString &address = "", const QString &name = "");
     ~ContactsDialog() override;
 
     QString getAddress();
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index da669e0..31c39ff 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -289,7 +289,6 @@ MainWindow::MainWindow(AppContext *ctx, QWidget *parent) :
     connect(ui->historyWidget, &HistoryWidget::resendTransaction, this, &MainWindow::onResendTransaction);
 
     // Contacts
-    connect(ui->contactWidget, &ContactsWidget::addContact, this, &MainWindow::onAddContact);
     connect(ui->contactWidget, &ContactsWidget::fillAddress, ui->sendWidget, &SendWidget::fillAddress);
 
     // Open alias
@@ -1055,16 +1054,6 @@ void MainWindow::onResendTransaction(const QString &txid) {
     dialog->deleteLater();
 }
 
-void MainWindow::onAddContact(const QString &address, const QString &name) {
-    bool addressValid = WalletManager::addressValid(address, m_ctx->currentWallet->nettype());
-    if (!addressValid)
-        QMessageBox::warning(this, "Invalid address", "Invalid address");
-    else {
-        m_ctx->currentWallet->addressBook()->addRow(address, "", name);
-        m_ctx->storeWallet();
-    }
-}
-
 void MainWindow::importContacts() {
     const QString targetFile = QFileDialog::getOpenFileName(this, "Import CSV file", QDir::homePath(), "CSV Files (*.csv)");
     if(targetFile.isEmpty()) return;
diff --git a/src/mainwindow.h b/src/mainwindow.h
index d6234be..366a1d8 100644
--- a/src/mainwindow.h
+++ b/src/mainwindow.h
@@ -118,7 +118,6 @@ public slots:
     void onWalletOpenPasswordRequired(bool invalidPassword, const QString &path);
     void onViewOnBlockExplorer(const QString &txid);
     void onResendTransaction(const QString &txid);
-    void onAddContact(const QString &address, const QString &name);
     void importContacts();
     void showRestoreHeightDialog();
     void importTransaction();