diff --git a/Layout/default/Preorder/Form.php b/Layout/default/Preorder/Form.php
index d71fb9e33..bd426ceee 100644
--- a/Layout/default/Preorder/Form.php
+++ b/Layout/default/Preorder/Form.php
@@ -301,7 +301,6 @@
     }
   
     
-    
     $("#product_id").select2({
       allowClear: true,
       placeholder: ""
@@ -392,6 +391,7 @@
               .data("tuer", unit.tuer)
               .data("zusatz", unit.zusatz);
           
+          afterHausnummerChange();
           
         });
         
@@ -453,10 +453,24 @@
       }
     });
     
+    
+    <?php if($preorder->adb_hausnummer_id): ?>
+      console.log("Hausnummer");
+      $('#adb_hausnummer_id').trigger("change");
+      // afterHausnummerChange() will be called by change event
+    <?php endif; ?>
   });
   
   
 
+  function afterHausnummerChange() {
+    <?php if($preorder->adb_wohneinheit_id): ?>
+      console.log("selecting wohneinheit");
+      $('#adb_wohneinheit_id option[value=<?=$preorder->adb_wohneinheit_id?>]').prop("selected", true);
+      $('#adb_wohneinheit_id').trigger("change");
+    <?php endif; ?>
+  }
+
   function updateSetupProduct(type) {
     if(type == "provision") {
       $('#setup_product_id').val($("#setup-provision select").val());
diff --git a/Layout/default/Preorder/Index.php b/Layout/default/Preorder/Index.php
index 206de80c5..b289d5f61 100644
--- a/Layout/default/Preorder/Index.php
+++ b/Layout/default/Preorder/Index.php
@@ -55,7 +55,7 @@
                 <td>
                   <?=$preorder->adb_hausnummer->strasse->name?>
                   <?=$preorder->adb_hausnummer->hausnummer?><br />
-                  <?=($preorder->adb_wohneinheit_id) ? $preorder->adb_wohneinheit."<br />" : ""?>
+                  <?=($preorder->adb_wohneinheit_id) ? ((string)$preorder->adb_wohneinheit ? $preorder->adb_wohneinheit."<br />" : "") : "<i class='text-pink'>&lt;keine Wohneinheit&gt;</i><br />"?>
                   <?=$preorder->adb_hausnummer->plz->plz?>
                   <?=$preorder->adb_hausnummer->strasse->ortschaft->name?>
                 </td>
diff --git a/application/Api/v1/PreorderApicontroller.php b/application/Api/v1/PreorderApicontroller.php
index 4c522fc31..f05cbe86b 100644
--- a/application/Api/v1/PreorderApicontroller.php
+++ b/application/Api/v1/PreorderApicontroller.php
@@ -37,7 +37,7 @@ class PreorderApicontroller extends mfBaseApicontroller {
     }
     
     $type = $this->post['type'];
-    if($type != "provision" && $type != "order") {
+    if($type != "interest" && $type != "provision") {
       return mfResponse::BadRequest(["message" => "Unknown type"]);
     }
     
@@ -50,10 +50,10 @@ class PreorderApicontroller extends mfBaseApicontroller {
     }
     
     // check address
-    if(!property_exists($this->post['address'],"street") ||
-       !property_exists($this->post['address'],"housenumber") ||
-       !property_exists($this->post['address'],"zip") ||
-       !property_exists($this->post['address'],"city")
+    if(!property_exists($this->post['address'],"street") || !$this->post['address']->street ||
+       !property_exists($this->post['address'],"housenumber") || !$this->post['address']->housenumber ||
+       !property_exists($this->post['address'],"zip") || !$this->post['address']->zip ||
+       !property_exists($this->post['address'],"city") || !$this->post['address']->city
     ) {
       return mfResponse::BadRequest(['message' => "Mandatory address fields missing"]);
     }
@@ -67,20 +67,19 @@ class PreorderApicontroller extends mfBaseApicontroller {
     
     $unit_search = [];
     foreach(['block','stiege','stock','tuer'] as $key) {
-      if(property_exists($this->post['address'], $key) && trim($this->post['address']->key)) {
+      if(property_exists($this->post['address'], $key) && trim($this->post['address']->$key)) {
         $unit_search[$key] = trim($this->post['address']->$key);
       }
     }
-    
+
     // check customer
-    
     $customer = $this->post['customer'];
     
-    if(!property_exists($customer,"firstname") ||
-       !property_exists($customer,"lastname") ||
-       !property_exists($customer,"street") ||
-       !property_exists($customer,"zip") ||
-       !property_exists($customer,"city")
+    if(!property_exists($customer,"firstname") || !$customer->firstname ||
+       !property_exists($customer,"lastname") || !$customer->lastname ||
+       !property_exists($customer,"street") || !$customer->street ||
+       !property_exists($customer,"zip") || !$customer->zip ||
+       !property_exists($customer,"city") || !$customer->city
     ) {
       return mfResponse::BadRequest(['message' => "Mandatory customer fields missing"]);
     }
@@ -120,12 +119,24 @@ class PreorderApicontroller extends mfBaseApicontroller {
       
       $unit = $this->db()->fetch_object($res);
       //var_dump($this->db()->num_rows($res), $this->db()->fetch_object($res));
-      
+    } else {
+      // if all unit values are empty try to find the unit with all empty values
+      // failure is not an error, but must be checked by a human at some point
+      $sql = "SELECT * FROM view_wohneinheit WHERE hausnummer_id=".$address->hausnummer_id." AND (block = '' OR block IS NULL) AND (stiege = '' OR stiege IS NULL) AND (stock = '' OR stock IS NULL) AND (tuer = '' OR tuer IS NULL)";
+      $res = $this->db()->query($sql);
+      if($this->db()->num_rows($res)) {
+        $unit = $this->db()->fetch_object($res);
+      }
     }
+    //var_dump($unit);exit;
     
     $preorder_data = [];
     $preorder_data['preordercampaign_id'] = $this->campaign->id;
     $preorder_data['type'] = $type;
+    $preorder_data['submit_type'] = "api";
+    if($this->request_json) {
+      $preorder_data['submit_request'] = $this->request_json;
+    }
     $preorder_data['adb_hausnummer_id'] = $address->hausnummer_id;
     
     if($unit) {
@@ -148,7 +159,19 @@ class PreorderApicontroller extends mfBaseApicontroller {
       }
     }
     
-    var_dump($preorder_data);exit;
+    
+    
+    $preorder = PreorderModel::create($preorder_data);
+    $preorder->createUcode();
+    $preorder_id = $preorder->save();
+    
+    if(!$preorder_id || !$preorder->ucode) {
+      return mfResponse::InternalServerError();
+    }
+    
+    return mfResponse::Ok(["code" => $preorder->ucode]);
+    
+    var_dump($preorder);exit;
     
     
     var_dump($this->post);exit;
diff --git a/application/Preorder/Preorder.php b/application/Preorder/Preorder.php
index 61e5a5255..03a07369c 100644
--- a/application/Preorder/Preorder.php
+++ b/application/Preorder/Preorder.php
@@ -8,6 +8,26 @@ class Preorder extends mfBaseModel {
   private $adb_hausnummer;
   private $adb_wohneinheit;
   
+  
+  public function createUcode() {
+    $ucode = $this->generateNewUcode();
+    while(PreorderModel::search(['ucode' => $ucode])) {
+      $ucode = $this->generateNewUcode();
+    }
+    $this->ucode = $ucode;
+    return $this->ucode;
+  }
+  
+  private function generateNewUcode() {
+    $chars = '23456789ABCDEFGHJKLMNPQRSTUVWXYZ';
+    $charsLength = strlen($chars);
+    $ucode = '';
+    for ($i = 0; $i < 8; $i++) {
+        $ucode .= $chars[rand(0, $charsLength - 1)];
+    }
+    return $ucode;
+  }
+  
   public function getProperty($name) {
     if($this->$name == null) {
       
diff --git a/application/Preorder/PreorderModel.php b/application/Preorder/PreorderModel.php
index c28dfda14..d4841d5ce 100644
--- a/application/Preorder/PreorderModel.php
+++ b/application/Preorder/PreorderModel.php
@@ -1,6 +1,7 @@
 <?php
 
 class PreorderModel {
+  public $ucode;
   public $preordercampaign_id;
   public $adb_hausnummer_id;
   public $adb_wohneinheit_id;
@@ -26,6 +27,8 @@ class PreorderModel {
   public $city;
   public $phone;
   public $email;
+  public $submit_type;
+  public $submit_request;
   
   public $note;
   
@@ -155,6 +158,13 @@ class PreorderModel {
       }
     }
     
+    if(array_key_exists("ucode", $filter)) {
+      $ucode = FronkDB::singleton()->escape($filter['ucode']);
+      if($ucode) {
+        $where .= " AND ucode like '%$ucode%'";
+      }
+    }
+    
     
     //var_dump($filter, $where);exit;
     return $where;
diff --git a/lib/mvcfronk/mfBase/mfBaseApicontroller.php b/lib/mvcfronk/mfBase/mfBaseApicontroller.php
index 7030566e6..464252e2e 100644
--- a/lib/mvcfronk/mfBase/mfBaseApicontroller.php
+++ b/lib/mvcfronk/mfBase/mfBaseApicontroller.php
@@ -18,6 +18,7 @@ class mfBaseApicontroller {
   protected $apiversion;
   protected $headers = [];
   protected $route;
+  protected $request_json;
   protected $get = [];
   protected $post = [];
   protected $format = "default";
@@ -143,6 +144,7 @@ class mfBaseApicontroller {
     $json_request = json_decode($body);
     if(json_last_error() === JSON_ERROR_NONE) {
       //var_dump((array)$json_request);exit;
+      $this->request_json = $body;
       return (array)$json_request;
     }