diff --git a/Layout/default/Preorder/Index.php b/Layout/default/Preorder/Index.php
index 3f4724d2d..9be42013f 100644
--- a/Layout/default/Preorder/Index.php
+++ b/Layout/default/Preorder/Index.php
@@ -418,11 +418,6 @@ $pagination_entity_name = "Vorbestellungen";
                                     <button type="submit" formaction="<?=self::getUrl("Preorder", "export")?>" id="export-button" class="btn btn-outline-success"><i class="fas fa-download"></i> CSV-Export</button>
                                 <?php endif; ?>
 
-<!--                               i need a dropdown with 2 options beautifull dropdown no select
- Gelöschte Bestellungen mit Workorder (button with href)
- Wohnung - Verkabelung erledigt (button with href)
- -->
-
                                 <div class="dropdown">
                                     <button class="btn btn-outline-primary dropdown-toggle" type="button" id="dropdownMenuButton" data-bs-toggle="dropdown" aria-expanded="false">
                                         Filter-Vorlagen <i class="fas fa-caret-down"></i>
@@ -430,6 +425,9 @@ $pagination_entity_name = "Vorbestellungen";
                                     <ul class="dropdown-menu" aria-labelledby="dropdownMenuButton">
                                         <li><a class="dropdown-item" href="<?=self::getUrl("Preorder", "Index", ["filter" => ["status" => [21,22,23,24,25], "rimo_workorder" => 1, "borderpoint" => "all"]])?>">Gelöschte Bestellungen mit Workorder</a></li>
                                         <li><a class="dropdown-item" href="<?=self::getUrl("Preorder", "Index", ["filter" => ["preorder_status_flags" => [4], "connection_type" => ["apartment", "apartment-building"], "borderpoint" => "all"]])?>">Wohnung - Verkabelung erledigt</a></li>
+                                        <?php if ($me->isAdmin() || $me->address->id == 209): ?>
+                                        <li><a class="dropdown-item" href="<?=self::getUrl("Preorder", "Index", ["filter" => ["onlyShowCustomMailSent" => 1]])?>">Bestellungen mit gesendeter Custom-300 Benachrichtigung</a></li>
+                                        <?php endif; ?>
                                     </ul>
                                 </div>
 
diff --git a/Layout/default/Preorder/include/preorder-detail.php b/Layout/default/Preorder/include/preorder-detail.php
index 51f68642b..70926eda6 100644
--- a/Layout/default/Preorder/include/preorder-detail.php
+++ b/Layout/default/Preorder/include/preorder-detail.php
@@ -102,7 +102,66 @@
                                 </div>
                                 <?php endif; ?>
                             </td>
-                        </tr><tr>
+                        </tr>
+
+<!--                            add new checkbox field here called "Verrechnet" and if $preorder->billed is not null or 0 show the unix date, also only show this when
+ preordercampaign -> network_id -> network -> owner_id === 209
+
+ then show billed = timestamp (no input as the checkbox is the only thing that can be changed)
+ also show billed_by
+
+ -->
+                            <?php if($preorder->campaign->network->owner_id === "209"): ?>
+                            <tr>
+                                <th>Verrechnet:</th>
+                                <td>
+                                    <div class="flex items-center space-x-2">
+                                        <input
+                                                type="checkbox"
+                                                id="preorder-detail-billed-<?=$preorder->id?>"
+                                                class="form-checkbox h-5 w-5 text-blue-600 rounded focus:ring-blue-500"
+                                            <?=($preorder->billed) ? 'checked' : ''?>
+                                                onchange="updatePreorderBilled(<?=$preorder->id?>, this.checked)"
+                                        />
+                                        <label for="preorder-detail-billed-<?=$preorder->id?>" class="text-gray-700 mb-0">Verrechnet</label>
+                                    </div>
+
+                                    <?php if($preorder->billed_by): ?>
+                                        <div class="mt-2 text-sm text-gray-600" id="billed_text">Verrechnet durch: <?=(new User($preorder->billed_by))->name?> am <?=date("d.m.Y H:i", $preorder->billed)?> Uhr</div>
+                                    <?php endif; ?>
+                                </td>
+                            <script>
+                                // console log if changed
+                                function updatePreorderBilled(preorderId, isChecked) {
+                                    console.log("Updating billed status for preorder " + preorderId + ": " + (isChecked ? "checked" : "unchecked"));
+                                    $.ajax({
+                                        url: '<?=self::getUrl("Preorder", "Api")?>?do=updateBilled',
+                                        type: 'POST',
+                                        data: {
+                                            do: 'updateBilled',
+                                            id: preorderId,
+                                            billed: isChecked ? 1 : 0
+                                        },
+                                        success: function(response) {
+                                            console.log("Update successful:", response);
+                                            if (isChecked) {
+                                                $("#billed_text").html(`Verrechnet durch: ${response.result.billed_by_name} am ${response.result.billed_date} Uhr`);
+                                                window.notify("success", "Preorder wurde als verrechnet markiert.");
+                                            } else {
+                                                $("#billed_text").html("");
+                                                window.notify("success", "Preorder wurde als nicht verrechnet markiert.");
+                                            }
+                                        },
+                                        error: function(xhr, status, error) {
+                                            console.error("Update failed:", error);
+                                            window.notify("error", "Fehler beim Aktualisieren des Verrechnungsstatus: " + error);
+                                        }
+                                    });
+                                }
+                            </script>
+                        </tr>
+                            <?php endif; ?>
+                        <tr>
                         <th>Erstellt:</th>
                         <td class="text-monospace"><?=date("d.m.Y H:i",$preorder->create)?> (<?=$preorder->creator->name?>)</td>
                       </tr><tr>
diff --git a/application/Preorder/PreorderController.php b/application/Preorder/PreorderController.php
index d9dab2f30..758ea3e5a 100644
--- a/application/Preorder/PreorderController.php
+++ b/application/Preorder/PreorderController.php
@@ -1080,6 +1080,9 @@ class PreorderController extends mfBaseController {
             case "setBilled":
                 $return = $this->setBilledApi();
                 break;
+            case "updateBilled":
+                $return = $this->updateBilledApi();
+                break;
             default:
                 $return = false;
         }
@@ -1610,4 +1613,29 @@ class PreorderController extends mfBaseController {
         return ["message" => "Workorder deleted successfully", "id" => $preorder->id, "wid" => $wo_id];
     }
 
+    private function updateBilledApi() {
+        $preorder_id = $this->request->id;
+
+        if (!is_numeric($preorder_id) || $preorder_id < 1) return false;
+
+        $preorder = new Preorder($preorder_id);
+        if (!$preorder->id) return false;
+
+        $billed = $this->request->billed ? (string)time() : "0";
+
+        $preorder->billed = $billed;
+        $preorder->billed_by = $this->me->id;
+
+        if (!$preorder->save()) return false;
+
+        return [
+            "message" => "Billed status updated successfully",
+            "id" => $preorder_id,
+            "billed" => $billed,
+            "billed_by_name" => $this->me->name,
+            "billed_by_id" => $this->me->id,
+            "billed_date" => date("d.m.Y H:i", $preorder->billed ? $preorder->billed : time())
+        ];
+    }
+
 }
diff --git a/application/Preorder/PreorderModel.php b/application/Preorder/PreorderModel.php
index edd9d6a6e..a32195ed8 100644
--- a/application/Preorder/PreorderModel.php
+++ b/application/Preorder/PreorderModel.php
@@ -1076,6 +1076,13 @@ class PreorderModel
             }
         }
 
+        if (array_key_exists("onlyShowCustomMailSent", $filter)) {
+            // Only apply the filter if the value is truthy (e.g., true, 1)
+            if ($filter['onlyShowCustomMailSent']) {
+                $where .= " AND tt_preorder.id IN (SELECT preorder_id FROM PreorderStatusnotificationLog WHERE email_type = '300-custom')";
+            }
+        }
+
         // custom where clause
         if (array_key_exists("add-where", $filter)) {
             $where .= " " . $filter['add-where'];
diff --git a/db/migrations/20250703110000_preorder_add_billing_fields.php b/db/migrations/20250703110000_preorder_add_billing_fields.php
new file mode 100644
index 000000000..a5604d2bd
--- /dev/null
+++ b/db/migrations/20250703110000_preorder_add_billing_fields.php
@@ -0,0 +1,35 @@
+<?php
+declare(strict_types=1);
+
+use Phinx\Migration\AbstractMigration;
+
+final class PreorderAddBillingFields extends AbstractMigration
+{
+    public function up(): void
+    {
+        if($this->getEnvironment() == "thetool") {
+            $table = $this->table("Preorder");
+            $table->addColumn("billed", "integer", ["default" => 0, "after" => "billing_period", "comment" => "UNIX timestamp of when the preorder was billed or 0 if not billed"]);
+            $table->addColumn("billed_by", "integer", ["default" => 0, "after" => "billing_period", "comment" => "User ID of the user who billed the preorder, 0 if not billed"]);
+            $table->update();
+        }
+        
+        if($this->getEnvironment() == "addressdb") {
+          
+        }
+    }
+
+    public function down(): void
+    {
+        if($this->getEnvironment() == "thetool") {
+            $table = $this->table("Preorder");
+            $table->removeColumn("billed");
+            $table->removeColumn("billed_by");
+            $table->update();
+        }
+        
+        if($this->getEnvironment() == "addressdb") {
+          
+        }
+    }
+}