diff --git a/bizmatch-server/src/listings/commercial-property.service.ts b/bizmatch-server/src/listings/commercial-property.service.ts
index aab76cb..a462540 100644
--- a/bizmatch-server/src/listings/commercial-property.service.ts
+++ b/bizmatch-server/src/listings/commercial-property.service.ts
@@ -162,8 +162,22 @@ export class CommercialPropertyService {
   // #### CREATE ########################################
   async createListing(data: CommercialPropertyListing): Promise<CommercialPropertyListing> {
     try {
+      // Hole die nächste serialId von der Sequence
+      const sequenceResult = await this.conn.execute(sql`SELECT nextval('commercials_json_serial_id_seq') AS serialid`);
+
+      // Prüfe, ob ein gültiger Wert zurückgegeben wurde
+      if (!sequenceResult.rows || !sequenceResult.rows[0] || sequenceResult.rows[0].serialid === undefined) {
+        throw new Error('Failed to retrieve serialId from sequence commercials_json_serial_id_seq');
+      }
+
+      const serialId = Number(sequenceResult.rows[0].serialid); // Konvertiere BIGINT zu Number
+      if (isNaN(serialId)) {
+        throw new Error('Invalid serialId received from sequence');
+      }
+
       data.created = data.created ? (typeof data.created === 'string' ? new Date(data.created) : data.created) : new Date();
       data.updated = new Date();
+      data.serialId = Number(serialId);
       CommercialPropertyListingSchema.parse(data);
       const { id, email, ...rest } = data;
       const convertedCommercialPropertyListing = { email, data: rest };