diff --git a/ajax/cronservice/cancelRegistration.php b/ajax/cronservice/cancelRegistration.php
new file mode 100644
index 0000000000000000000000000000000000000000..abfd1d526695a5b2bb420932818752689c3cea99
--- /dev/null
+++ b/ajax/cronservice/cancelRegistration.php
@@ -0,0 +1,16 @@
+<?php
+
+/**
+ * Requests the server to cancel the registration
+ *
+ * @param - The email which was used for registration.
+ */
+QUI::$Ajax->registerFunction(
+    'package_quiqqer_cron_ajax_cronservice_cancelRegistration',
+    function () {
+        $CronService = new \QUI\Cron\CronService();
+        $CronService->cancelRegistration();
+    },
+    array(),
+    ''
+);
diff --git a/bin/CronServiceWindow.css b/bin/CronServiceWindow.css
index e6e391b04bb2da384b243af5748eedf4dea5de4f..826d0880acfae36c82afc003c866a46f4133a99e 100644
--- a/bin/CronServiceWindow.css
+++ b/bin/CronServiceWindow.css
@@ -1,7 +1,7 @@
 
 .quiqqer-cron-cronservicewindow-btn-openRegistration {
-    margin : 30px auto 0 auto;
     float  : right;
+    margin : 30px auto 0 auto;
 }
 
 .quiqqer-cron-cronserviceWindow h2 {
@@ -28,8 +28,8 @@
 }
 
 .quiqqer-cron-cronservicewindow-buttons {
-    text-align : center;
     margin-top : 40px;
+    text-align : center;
     width      : 100%;
 }
 
@@ -71,16 +71,24 @@
 }
 
 .quiqqer-cron-cronservicewindow-registration-txt-email {
-    width      : 100%;
     margin-top : 6px;
+    width      : 100%;
 }
 
 .quiqqer-cron-cronservicewindow-btn-register {
-    margin-top : 20px;
     float      : right;
+    margin-top : 20px;
 }
 
 .quiqqer-cron-cronservicewindow-registration-success-btn-confirm {
     float  : right;
     margin : 15px 0 0 0;
+}
+
+.quiqqer-cron-cronservicewindow-registration-success-btn-cancel-text {
+    overflow      : hidden;
+    text-align    : center;
+    text-overflow : ellipsis;
+    white-space   : nowrap;
+    width         : 100%;
 }
\ No newline at end of file
diff --git a/bin/CronServiceWindow.js b/bin/CronServiceWindow.js
index 7fdd731ddcd3ba135c11110fa4536e77c3b6a2dd..f48c08a6e7a3ae4cc5f204583b3f7063fe600590 100644
--- a/bin/CronServiceWindow.js
+++ b/bin/CronServiceWindow.js
@@ -108,9 +108,7 @@ define('package/quiqqer/cron/bin/CronServiceWindow', [
 
 
                 // Register/Unregister Button
-                if (self.status)
-                // Get the button text : register or unregister
-                {
+                if (self.status) {
                     var btnText = QUILocale.get(lg, 'cron.window.cronservice.content.btn.register');
                 }
                 if (self.registered) {
@@ -119,20 +117,41 @@ define('package/quiqqer/cron/bin/CronServiceWindow', [
 
                 var Button = null;
                 if (self.status == 2) {
+                    // Resend Activation Button
                     Button = new QUIButton({
                         text     : QUILocale.get(lg, 'cron.window.cronservice.content.btn.resend.activation.mail'),
                         textimage: 'fa fa-envelope-o',
                         events   : {
-                            onClick: function (Button) {
+                            onClick: function () {
                                 self.resendActivationMail();
                             }
                         },
                         styles   : {
                             'float': 'none',
-                            margin : '0 auto',
-                            width  : 200
+                            width  : 'calc(50% - 5px)'
                         }
                     });
+
+                    // Cancel Registration Button
+                    new QUIButton({
+                        text  : '<span class="quiqqer-cron-cronservicewindow-registration-success-btn-cancel-text">' + QUILocale.get(lg, 'cron.window.cronservice.registration.button.text.cancel') + '</span>',
+                        events: {
+                            onClick: function (Button) {
+                                Button.setAttribute('text', QUILocale.get('quiqqer/cron', 'cron.window.cronservice.content.btn.unregister.confirm'));
+                                if (Button.getAttribute('clickcnt') == 1) {
+                                    self.cancelRegistration().then(function () {
+                                        self.refresh();
+                                    });
+                                }
+                                Button.setAttribute('clickcnt', 1);
+                            }
+                        },
+                        styles: {
+                            'float': 'none',
+                            margin : '0 10px 0 0',
+                            width  : 'calc(50% - 5px)'
+                        }
+                    }).inject(Buttons);
                 } else {
                     Button = new QUIButton({
                         text     : btnText,
@@ -216,9 +235,12 @@ define('package/quiqqer/cron/bin/CronServiceWindow', [
             }).inject(this.$Elm).show();
         },
 
+        /**
+         * Shows the registration success sheet, which contains information about the activation email
+         */
         showRegistrationSuccess: function () {
             var self = this;
-            
+
             new QUISheets({
                 header : true,
                 icon   : 'fa fa-cloud',
@@ -281,6 +303,23 @@ define('package/quiqqer/cron/bin/CronServiceWindow', [
             });
         },
 
+        /**
+         * Cancels the registration
+         * @returns {*}
+         */
+        cancelRegistration: function () {
+            return new Promise(function (resolve, reject) {
+                QUIAjax.get('package_quiqqer_cron_ajax_cronservice_cancelRegistration', resolve, {
+                    'package': lg,
+                    onError  : reject
+                });
+            });
+        },
+
+        /**
+         * Sends the activation mail again
+         * @returns {*}
+         */
         resendActivationMail: function () {
             return new Promise(function (resolve, reject) {
                 QUIAjax.get('package_quiqqer_cron_ajax_cronservice_resendActivation', resolve, {
diff --git a/locale.xml b/locale.xml
index 4ea8685fc47617e2dbce68c9591cea8b4a59ea5e..ab4e64bec090a2826303a7f52b2218186231922a 100644
--- a/locale.xml
+++ b/locale.xml
@@ -448,5 +448,9 @@ This is works with an external server on which QUIQQER systems can register them
             <de><![CDATA[Verstanden]]></de>
             <en><![CDATA[Okay]]></en>
         </locale>
+        <locale name="cron.window.cronservice.registration.button.text.cancel">
+            <de><![CDATA[Registrierung abbrechen]]></de>
+            <en><![CDATA[Cancel registration]]></en>
+        </locale>
     </groups>
 </locales>
\ No newline at end of file
diff --git a/src/QUI/Cron/CronService.php b/src/QUI/Cron/CronService.php
index 578d7cbe28730236b1f8a6bc63c8ab5b119be364..db503c698425a9b91829f43a7db0bdcaebdb8674 100644
--- a/src/QUI/Cron/CronService.php
+++ b/src/QUI/Cron/CronService.php
@@ -8,7 +8,7 @@ use QUI\System\Log;
 class CronService
 {
 
-    const CRONSERVICE_URL = "https://cron.quiqqer.com";
+    const CRONSERVICE_URL = "http://server.cronservice.flo.pcsg";
 
     private $domain;
     private $https;
@@ -112,7 +112,6 @@ class CronService
      */
     public function resendActivationMail()
     {
-
         if (!isset($this->domain) || empty($this->domain)) {
             throw new Exception("Could not get the instances domain.");
         }
@@ -125,6 +124,24 @@ class CronService
         );
     }
 
+    /**
+     * Attempts to cancel the registration on the server
+     * @throws Exception
+     */
+    public function cancelRegistration()
+    {
+        Log::addDebug("");
+        if (!isset($this->domain) || empty($this->domain)) {
+            throw new Exception("Could not get the instances domain.");
+        }
+
+        $this->makeServerAjaxCall(
+            "package_pcsg_cronservice_ajax_cancelRegistration",
+            array(
+                "domain" => $this->domain
+            )
+        );
+    }
 
     /**
      * Sends an ajax request to the cronservice server.
@@ -277,4 +294,5 @@ class CronService
 
         return $token;
     }
+
 }