diff --git a/Layout/default/Preorder/Index.php b/Layout/default/Preorder/Index.php
index 3fa4d331d..e8df26cb2 100644
--- a/Layout/default/Preorder/Index.php
+++ b/Layout/default/Preorder/Index.php
@@ -1353,6 +1353,7 @@ $pagination_entity_name = "Vorbestellungen";
             // toggle controls
             $("#preorder-detail-activationdate-" + pid + "-text").toggle();
             $("#preorder-detail-activationdate-" + pid + "-input").toggle();
+            $("#preorder-detail-activation-billing-" + pid).toggle();
 
             return false;
         }
@@ -1363,6 +1364,9 @@ $pagination_entity_name = "Vorbestellungen";
             }
 
             var value = $("#preorder-detail-activationdate-" + pid + "-input input").val();
+            var activation_billing = $("#preorder-detail-activation-billing-" + pid + " input[type='checkbox'").is(":checked") ? 1 : 0;
+            console.log($("#preorder-detail-activation-billing-" + pid + " input[type='checkbox'"));
+            console.log(activation_billing);
 
             //console.log("add opacity-5 to ")
             $("#preorder-" + pid + "-body").addClass("opacity-5");
@@ -1378,17 +1382,25 @@ $pagination_entity_name = "Vorbestellungen";
                 {
                     'do': "saveActivationdate",
                     id: pid,
-                    activation_date: value
+                    activation_date: value,
+                    activation_billing: activation_billing
                 },
                 function(success) {
                     if(success.status == "OK") {
                         console.log(success);
                         var new_activationdate = success.result.activation_date;
+                        var new_activation_billing = success.result.activation_billing;
                         var pid = success.result.preorder_id;
                         //console.log(updates);
                         $("#preorder-detail-activationdate-" + pid + "-textpart").text(new_activationdate);
                         $("#preorder-detail-activationdate-" + pid + "-input").val(new_activationdate);
 
+                        console.log($("#preorder-detail-activationdate-" + pid + "-activation-billing-part"));
+                        $("#preorder-detail-activationdate-" + pid + "-activation-billing-part").text("");
+                        if(new_activation_billing) {
+                            $("#preorder-detail-activationdate-" + pid + "-activation-billing-part").text("(Billing ab Aktivierung)");
+                        }
+
                         $("#preorder-detail-activationdate-" + pid + "-text").addClass("text-success");
                         setTimeout(() => { $("#preorder-detail-activationdate-" + pid + "-text").removeClass("text-success") }, 1500);
 
diff --git a/Layout/default/Preorder/include/preorder-detail.php b/Layout/default/Preorder/include/preorder-detail.php
index 35b970bc4..51f68642b 100644
--- a/Layout/default/Preorder/include/preorder-detail.php
+++ b/Layout/default/Preorder/include/preorder-detail.php
@@ -89,7 +89,7 @@
                             <th>Aktivierungsdatum (Status 500):</th>
                             <td>
                                 <?php if($preorder->getStatuschangeTo(500)): ?>
-                                <span id="preorder-detail-activationdate-<?=$preorder->id?>-text" data-activationdate="<?=($preorder->getStatuschangeTo(500)) ? (new DateTime("@".$preorder->getStatuschangeTo(500)))->format("d.m.Y") : ""?>"><span id="preorder-detail-activationdate-<?=$preorder->id?>-textpart"><?=($preorder->getStatuschangeTo(500)) ? (new DateTime("@".$preorder->getStatuschangeTo(500)))->format("d.m.Y") : ""?></span> <a href="#" onclick="return toggleActivationdateControl(<?=$preorder->id?>)"><i class="fas fa-fw fa-edit"></i></a></span>
+                                <span id="preorder-detail-activationdate-<?=$preorder->id?>-text" data-activationdate="<?=($preorder->getStatuschangeTo(500)) ? (new DateTime("@".$preorder->getStatuschangeTo(500)))->format("d.m.Y") : ""?>"><span id="preorder-detail-activationdate-<?=$preorder->id?>-textpart"><?=($preorder->getStatuschangeTo(500)) ? (new DateTime("@".$preorder->getStatuschangeTo(500)))->format("d.m.Y") : ""?></span> <span id="preorder-detail-activationdate-<?=$preorder->id?>-activation-billing-part"><?=($preorder->activation_billing) ? "(Billing ab Aktivierung)" : ""?></span> <a href="#" onclick="return toggleActivationdateControl(<?=$preorder->id?>)"><i class="fas fa-fw fa-edit"></i></a></span>
                                 <div class="input-group" id="preorder-detail-activationdate-<?=$preorder->id?>-input" style="display:none">
                                     <input type="text" class="form-control datepicker" value="<?=($preorder->getStatuschangeTo(500)) ? (new DateTime("@".$preorder->getStatuschangeTo(500)))->format("d.m.Y") : ""?>" />
                                     <div class="input-group-append">
@@ -97,6 +97,9 @@
                                         <button type="button" class="btn btn-secondary" title="Abbrechen" onclick="toggleActivationdateControl(<?=$preorder->id?>)"><i class="fas fa-times"></i></button>
                                     </div>
                                 </div>
+                                <div id="preorder-detail-activation-billing-<?=$preorder->id?>" class="mt-1 hidden">
+                                    <label><input type="checkbox" name="activation_billing" value="1" <?=($preorder->activation_billing) ? "checked='checked'" : "" ?> /> Verrechnung ab Aktivierungsdatum (Wenn vor globalem Verrechnungsstart)</label><br />
+                                </div>
                                 <?php endif; ?>
                             </td>
                         </tr><tr>
diff --git a/application/Preorder/PreorderController.php b/application/Preorder/PreorderController.php
index 89b206192..d9dab2f30 100644
--- a/application/Preorder/PreorderController.php
+++ b/application/Preorder/PreorderController.php
@@ -1177,6 +1177,9 @@ class PreorderController extends mfBaseController {
     private function saveActivationdateApi() {
         $preorder_id = $this->request->id;
         $activation_date = $this->request->activation_date;
+        $activation_billing = $this->request->activation_billing ? 1 : 0;
+
+        $this->log->debug(print_r($this->request->get(), true));
 
         $preorder = new Preorder($preorder_id);
         if(!$preorder->id) {
@@ -1199,7 +1202,15 @@ class PreorderController extends mfBaseController {
         $history->changed = $activationdate->getTimestamp();
         $history->save();
 
-        return ["message" => "Activationdate saved successfully", "preorder_id" => $preorder_id, "activation_date" => $activation_date];
+        //$this->log->debug(print_r($preorder, true));
+        $this->log->debug(print_r($activation_billing, true));
+        if($preorder->activation_billing != $activation_billing) {
+            $preorder->activation_billing = $activation_billing;
+            $this->log->debug(print_r($preorder, true));
+            $preorder->save();
+        }
+
+        return ["message" => "Activationdate saved successfully", "preorder_id" => $preorder_id, "activation_date" => $activation_date, "activation_billing" => $activation_billing];
     }
 
     private function addWorkorderRemarkApi() {
diff --git a/application/Preorder/PreorderModel.php b/application/Preorder/PreorderModel.php
index 5e5fefd96..edd9d6a6e 100644
--- a/application/Preorder/PreorderModel.php
+++ b/application/Preorder/PreorderModel.php
@@ -64,6 +64,7 @@ class PreorderModel
     public $workorder_export_date;
     public $workorder_export_data;
     public $order_date;
+    public $activation_billing;
 
     public $cancel_request;
     public $cancel_request_by;
diff --git a/application/PreorderBilling/PreorderBilling.php b/application/PreorderBilling/PreorderBilling.php
index d70147dde..a56479e63 100644
--- a/application/PreorderBilling/PreorderBilling.php
+++ b/application/PreorderBilling/PreorderBilling.php
@@ -8,7 +8,7 @@ class PreorderBilling extends mfBaseModel {
     private $creator;
     private $editor;
 
-    public static $earliest_bill_date = "2025-01-01";
+    public static $earliest_bill_date = "2025-01-01"; // TODO: auslagern in config file
 
     public function getProperty($name) {
         if($this->$name == null) {
diff --git a/application/PreorderBilling/PreorderBillingController.php b/application/PreorderBilling/PreorderBillingController.php
index 05bef7059..adeb7e264 100644
--- a/application/PreorderBilling/PreorderBillingController.php
+++ b/application/PreorderBilling/PreorderBillingController.php
@@ -134,7 +134,7 @@ class PreorderBillingController extends mfBaseController {
         }
         $netowner_config = TT_PREORDER_BILLING[$netowner_id];
 
-        $earliest_bill_date = new DateTime(PreorderBilling::$earliest_bill_date);
+        $earliest_bill_date = new DateTime(PreorderBilling::$earliest_bill_date); // TODO: auslagern in config file
 
         $now_year = date("Y");
         $now_month = date("m");
@@ -180,7 +180,7 @@ class PreorderBillingController extends mfBaseController {
         $preorder_search = [
             "preordercampaign_id" => $campaign_ids,
             ">=status_code" => 244,
-            //"oaid" => "AT-8943-a1116acf.001",
+            //"oaid" => "AT-8943-f2c2ae10.001",
         ];
 
         $billing_records = [];
@@ -263,7 +263,6 @@ class PreorderBillingController extends mfBaseController {
             if($preorder->status->code >= 500) {
                 if($bill_operator_setup) $this->billSetup($preorder, "operator_setup", $bill_params);
                 if($bill_usage) $this->billOperatorPeriodic($preorder, $bill_params);
-                //exit;
             }
         }
 
@@ -589,7 +588,7 @@ class PreorderBillingController extends mfBaseController {
             $cancel_date = new DateTime("@".$cancel_change->changed);
         }
 
-        $first_bill_date = clone $status_change_date;
+
 
 
         // get earlier missing billing records and bill them too
@@ -642,10 +641,56 @@ class PreorderBillingController extends mfBaseController {
             }
             break;
         }
+
+        if($preorder->activation_billing) {
+            // bill from activation_date, even if it's before earliest_bill_date
+            $first_bill_date = clone $status_change_date;
+            $create_date = clone $earliest_bill_date;
+            $create_date->modify("first day of this month");
+            $create_date->modify("-1 month");
+            $create_date->setTime(0,0,0);
+
+            //var_dump($first_bill_date);
+            /*var_dump($create_date);
+            var_dump($earliest_bill_date);*/
+
+            // get months from activation date
+            $last_create_date = false;
+            while($create_date->format("Ym") < $earliest_bill_date->format("Ym")) {
+                //var_dump($create_date);
+                if($last_create_date) {
+                    //var_dump($create_dates);
+                    // just for safety / shouldn't happen
+                    break;
+                    //die("need-date ran out of dates");
+                }
+
+                //echo " - \$create_date ".$create_date->format("Y-m-d H:i:s")."<br />\n";
+                //echo " - \$earliest_bill_date ".$earliest_bill_date->format("Y-m-d H:i:s")."<br /><br />\n";
+                if($create_date->format("Y") == $first_bill_date->format("Y") && $create_date->format("m") == $first_bill_date->format("m")) {
+                    // this is the finish month, so set day back to day of finish_date
+                    $create_date->setDate($first_bill_date->format("Y"), $first_bill_date->format("m"), $first_bill_date->format("d"));
+                    $last_create_date = true;
+                }
+
+                $existing_bill = PreorderBilling::getFirst(["product_id" => $product->id, "preorder_id" => $preorder->id, "start_date" => $create_date->format("Y-m-d")]);
+                //var_dump($existing_bill);
+                if(!$existing_bill) {
+                    if($netoperator_config["billing-period"] == "quarterly" && $create_date->format("Ymd") > $latest_quarter_bill_date->format("Ymd")) {
+                        $this->log->debug(__METHOD__.": Skipping operator_usage ".$create_date->format("m/Y")." for preorder ".$preorder->id." because Billing date ".$create_date->format("Y-m-d")." is after latest_quarter_bill_date ".$latest_quarter_bill_date->format("Y-m-d"));
+                        return true;
+                    }
+                    $new_create_date = clone $create_date;
+                    $to_bill_dates[] = $new_create_date;
+                    $create_date->modify("-1 months");
+                    continue;
+                }
+                break;
+            }
+        }
         //var_dump($to_bill_dates);
         //exit;
 
-
         foreach($to_bill_dates as $start_date) {
             $end_date = clone $start_date;
             $end_date->modify("first day of this month");
diff --git a/db/migrations/20250625065640_preorder_add_activation_billing.php b/db/migrations/20250625065640_preorder_add_activation_billing.php
new file mode 100644
index 000000000..671f37719
--- /dev/null
+++ b/db/migrations/20250625065640_preorder_add_activation_billing.php
@@ -0,0 +1,33 @@
+<?php
+declare(strict_types=1);
+
+use Phinx\Migration\AbstractMigration;
+
+final class PreorderAddActivationBilling extends AbstractMigration
+{
+    public function up(): void
+    {
+        if($this->getEnvironment() == "thetool") {
+            $table = $this->table("Preorder");
+            $table->addColumn("activation_billing", "integer", ["default" => 0, "length" => \Phinx\Db\Adapter\MysqlAdapter::INT_TINY, "after" => "order_date"]);
+            $table->update();
+        }
+        
+        if($this->getEnvironment() == "addressdb") {
+          
+        }
+    }
+
+    public function down(): void
+    {
+        if($this->getEnvironment() == "thetool") {
+            $table = $this->table("Preorder");
+            $table->removeColumn("activation_billing");
+            $table->update();
+        }
+        
+        if($this->getEnvironment() == "addressdb") {
+          
+        }
+    }
+}