diff --git a/ReportImp/BeWoWalzPaiva/Service/CustomAccountingService.cs b/ReportImp/BeWoWalzPaiva/Service/CustomAccountingService.cs
new file mode 100644
index 000000000..6a0f1116a
--- /dev/null
+++ b/ReportImp/BeWoWalzPaiva/Service/CustomAccountingService.cs
@@ -0,0 +1,51 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Windows;
+using BeWo.Data.Access;
+using BeWo.Data.Entities;
+using BeWo.Service.DCEntityMapper;
+using BeWo.Service.Plugins;
+using BS.Shared;
+using BS.Shared.DataContracts;
+
+
+
+namespace BeWoWalzPaiva.Service
+{
+	public class CustomAccountingService : AccountingService
+    {
+
+        public override ServiceInvoice ErstelleStornoRechnung(InvoiceBaseDC ibdc)
+        {
+            var i = base.ErstelleStornoRechnung(ibdc);
+
+            SetzeRechnungsnummer(i.InvoiceBase, ibdc);
+            i.InvoiceBase.StornoInvoiceBaseOid = ibdc.InvoiceBaseOid.Value;
+            DAOFactory.GenericDAO.Insert(i);
+
+            var original = DAOFactory.GenericDAO.LoadByID<InvoiceBase>(ibdc.InvoiceBaseOid.Value);
+            original.StornoInvoiceBaseOid = i.Oid;
+            DAOFactory.GenericDAO.Update(original);
+
+            return i;
+        }
+
+        private void SetzeRechnungsnummer(InvoiceBase neu, InvoiceBaseDC alt)
+        {
+            if (!String.IsNullOrEmpty(neu.InvoiceNumber))
+            {
+                neu.InvoiceNumber = alt.InvoiceNumber + " Storno";
+            }
+
+            if (String.IsNullOrEmpty(neu.InvoiceTypeText))
+            {
+                neu.InvoiceTypeText = "Storno";
+            }
+            else
+            {
+                neu.InvoiceTypeText += " Storno";
+            }
+        }
+    }
+}
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