diff --git a/src/Controllers/BookingController.php b/src/Controllers/BookingController.php
index dd1f852..d3c8cbe 100644
--- a/src/Controllers/BookingController.php
+++ b/src/Controllers/BookingController.php
@@ -183,6 +183,13 @@ class BookingController
                 }
             }
 
+            // Belegbetrag in Metadaten aktualisieren
+            $totalBrutto = Booking::sumBruttoForBeleg($belegId);
+            \Steuerkram\Database::execute(
+                'UPDATE belege SET betrag_brutto = ?, updated_at = NOW() WHERE id = ?',
+                [$totalBrutto, $belegId]
+            );
+
             // Bankbuchung verknüpfen wenn aus Bank-Kontext
             $bankTxId = (int)($data['bank_tx_id'] ?? 0);
             if ($bankTxId > 0) {
diff --git a/src/Models/Booking.php b/src/Models/Booking.php
index df95c97..522beb1 100644
--- a/src/Models/Booking.php
+++ b/src/Models/Booking.php
@@ -407,6 +407,18 @@ class Booking
         return sprintf('BU-%s-%06d', $year, $next);
     }
 
+    /** Summiert betrag_brutto aller aktiven Hauptbuchungen eines Belegs. */
+    public static function sumBruttoForBeleg(int $belegId): float
+    {
+        $row = Database::fetchOne(
+            'SELECT COALESCE(SUM(betrag_brutto), 0) AS total
+             FROM bookings
+             WHERE beleg_id = ? AND is_reversal = 0 AND parent_booking_id IS NULL',
+            [$belegId]
+        );
+        return round((float)($row['total'] ?? 0), 2);
+    }
+
     public static function sumByYear(int $year): array
     {
         return Database::fetchAll(