diff --git a/application/Billing/BillingController.php b/application/Billing/BillingController.php
index eee5bb9bf..8a3512115 100644
--- a/application/Billing/BillingController.php
+++ b/application/Billing/BillingController.php
@@ -164,6 +164,14 @@ class BillingController extends mfBaseController {
         //$now_month = 11;
         //$now_day = 3;
 
+        $locked = new mfConfig("billing.running");
+        if($locked->value()) {
+            $this->layout()->setFlash("Läuft schon seit ".date("d.m.Y H:i", $locked->edit));
+            $this->redirect("Billing");
+        }
+        $locked->value(1);
+        $locked->save();
+
         // XXX only for 1st Billing after IVT Import
         // Locking to July 2024 and keeping it for now
         $yearly_not_before = new DateTime("2024-07-01");
@@ -467,6 +475,12 @@ class BillingController extends mfBaseController {
                 $data["billingaddress_id"] = ($contract->billingaddress_id) ? $contract->billingaddress_id : $contract->owner_id;
                 $data["customer_number"] = $contract->owner->customer_number;
                 $data["fibu_account_number"] = $fibu_account_num;
+
+                // TODO: Zahlungsziel / Skonto muss in Zukuft vom Contract übernommen werden
+                $data["fibu_payment_due"] = $owner->fibu_payment_due ?: TT_ADDRESS_DEFAULT_PAYMENT_DUE;
+                $data["fibu_payment_skonto"] = $owner->fibu_payment_skonto ?: 0;
+                $data["fibu_payment_skonto_rate"] = $owner->fibu_payment_skonto_rate ?: 0;
+
                 $data["company"] = $billingaddress->company;
                 $data["firstname"] = $billingaddress->firstname;
                 $data["lastname"] = $billingaddress->lastname;
@@ -758,6 +772,10 @@ class BillingController extends mfBaseController {
 
 
         }
+
+        $locked->value(0);
+        $locked->save();
+
         $this->layout()->setFlash("$i Contract Billing records generiert. $v Voicenumber Billing records generiert");
         $this->redirect("Billing");
 
diff --git a/application/Billing/BillingModel.php b/application/Billing/BillingModel.php
index 6892bd68d..f2a40ea0c 100644
--- a/application/Billing/BillingModel.php
+++ b/application/Billing/BillingModel.php
@@ -9,6 +9,9 @@ class BillingModel {
     public $billingaddress_id;
     public $customer_number;
     public $fibu_account_number;
+    public $fibu_payment_due;
+    public $fibu_payment_skonto;
+    public $fibu_payment_skonto_rate;
     public $sepa_date;
     public $sepa_id;
     public $sepa_last_date;
diff --git a/application/Invoice/InvoiceController.php b/application/Invoice/InvoiceController.php
index 8d41e60bf..1871ffd2e 100644
--- a/application/Invoice/InvoiceController.php
+++ b/application/Invoice/InvoiceController.php
@@ -483,9 +483,9 @@ class InvoiceController extends mfBaseController {
                 $invoice_data["billingaddress_id"] = $billingaddress_id;
                 $invoice_data["customer_number"] = $bill->customer_number;
                 $invoice_data["fibu_account_number"] = $bill->fibu_account_number;
-                $invoice_data["fibu_payment_due"] = $bill->fibu_payment_due;
-                $invoice_data["fibu_payment_skonto"] = $bill->fibu_payment_skonto;
-                $invoice_data["fibu_payment_skonto_rate"] = $bill->fibu_payment_skonto_rate;
+                $invoice_data["fibu_payment_due"] = $bill->fibu_payment_due ?: 14;
+                $invoice_data["fibu_payment_skonto"] = $bill->fibu_payment_skonto ?: 0;
+                $invoice_data["fibu_payment_skonto_rate"] = $bill->fibu_payment_skonto_rate ?: 0;
 
 
                 $invoice_data["sepa_date"] = $bill->sepa_date;
diff --git a/db/migrations/20250805170206_billing_add_payment_due.php b/db/migrations/20250805170206_billing_add_payment_due.php
new file mode 100644
index 000000000..93e5ae308
--- /dev/null
+++ b/db/migrations/20250805170206_billing_add_payment_due.php
@@ -0,0 +1,77 @@
+<?php
+declare(strict_types=1);
+
+use Phinx\Migration\AbstractMigration;
+
+final class BillingAddPaymentDue extends AbstractMigration
+{
+    public function up(): void
+    {
+        if($this->getEnvironment() == "thetool") {
+
+            $billing = $this->table("Billing");
+            $billing->addColumn("fibu_payment_due", "integer", ["null" => true, "default" => null, "after" => "fibu_account_number"]);
+            $billing->addColumn("fibu_payment_skonto", "integer", ["null" => false, "default" => 0, "after" => "fibu_payment_due"]);
+            $billing->addColumn("fibu_payment_skonto_rate", "integer", ["null" => false, "default" => 0, "after" => "fibu_payment_skonto"]);
+            $billing->addIndex("invoice_id");
+            $billing->addIndex("contract_id");
+            $billing->addIndex("start_date");
+            $billing->addIndex("end_date");
+            $billing->update();
+
+            $bv = $this->table("BillingVoicenumber");
+            $bv->addIndex("contract_id");
+            $bv->addIndex("voicenumber");
+            $bv->addIndex("start_date");
+            $bv->addIndex("end_date");
+            $bv->update();
+
+            $invoice = $this->table("Invoice");
+            $invoice->addIndex("invoice_number");
+            $invoice->addIndex("invoice_date");
+            $invoice->addIndex("owner_id");
+            $invoice->addIndex("billingaddress_id");
+            $invoice->addIndex("customer_number");
+            $invoice->save();
+          
+        }
+        
+        if($this->getEnvironment() == "addressdb") {
+          
+        }
+    }
+
+    public function down(): void
+    {
+        if($this->getEnvironment() == "thetool") {
+            $this->table("Billing")
+                ->removeColumn("fibu_payment_skonto_rate")
+                ->removeColumn("fibu_payment_skonto")
+                ->removeColumn("fibu_payment_due")
+                ->removeIndex("end_date")
+                ->removeIndex("start_date")
+                ->removeIndex("contract_id")
+                ->removeIndex("invoice_id")
+                ->update();
+
+            $this->table("BillingVoicenumber")
+                ->removeIndex("end_date")
+                ->removeIndex("start_date")
+                ->removeIndex("voicenumber")
+                ->removeIndex("contract_id")
+                ->update();
+
+            $this->table("Invoice")
+                ->removeIndex("customer_number")
+                ->removeIndex("billingaddress_id")
+                ->removeIndex("owner_id")
+                ->removeIndex("invoice_date")
+                ->removeIndex("invoice_number")
+                ->update();
+        }
+        
+        if($this->getEnvironment() == "addressdb") {
+          
+        }
+    }
+}