diff --git a/ReportImp/DiakonischesWerkRegensburg/Export/EGeckoExporter.cs b/ReportImp/DiakonischesWerkRegensburg/Export/EGeckoExporter.cs
index 57187531c..14ca653ed 100644
--- a/ReportImp/DiakonischesWerkRegensburg/Export/EGeckoExporter.cs
+++ b/ReportImp/DiakonischesWerkRegensburg/Export/EGeckoExporter.cs
@@ -37,10 +37,24 @@ namespace DiakonischesWerkRegensburg.Export
             var dt = ExecuteQuery(GetMonatlicheRechnungenSql(date), date);
             var doc = CreateXML(dt);
 
-            using (var sw = new StringWriter())
+            // Der Client schreibt QueryResult als Windows-1252 auf Platte (BeWoUtils.WriteFile).
+            // Damit die Datei trotzdem gültiges UTF-8 mit passender Deklaration ist, werden alle
+            // Nicht-ASCII-Zeichen (Umlaute etc.) als numerische Zeichenreferenzen kodiert.
+            var settings = new XmlWriterSettings
             {
-                doc.Save(sw);
-                return sw.ToString();
+                Encoding = Encoding.ASCII,
+                Indent = true,
+                OmitXmlDeclaration = true
+            };
+
+            using (var ms = new MemoryStream())
+            {
+                using (var writer = XmlWriter.Create(ms, settings))
+                {
+                    doc.Save(writer);
+                }
+
+                return "<?xml version=\"1.0\" encoding=\"utf-8\"?>" + Environment.NewLine + Encoding.ASCII.GetString(ms.ToArray());
             }
         }
 
@@ -163,7 +177,7 @@ namespace DiakonischesWerkRegensburg.Export
 	    INNER JOIN person p ON c.personoid = p.oid
 	    WHERE ib.AccountingPeriodEnd >= ':Monat_Start' AND ib.AccountingPeriodEnd < ':Monat_End' AND ib.IsActive = 1 AND ib.InvoiceId = 'Sammelrechnung' AND ib.IsExported = 0
 	    GROUP BY ib.Oid, ib.InvoiceNumber, ib.InvoiceDate, ib.AccountingPeriodEnd, c.Oid, c.DebitorNumber, p.LastName, p.FirstName 
-	UNION SELECT DISTINCT
+	UNION SELECT
 		    ib.InvoiceDate AS InvoiceDate,
 		    c.DebitorNumber AS CustomerDebitor,
 		    '1660' AS CustomerCostCenter,
@@ -171,7 +185,7 @@ namespace DiakonischesWerkRegensburg.Export
 		    CONCAT(p.LastName, ', ', p.FirstName) AS Verwendungszweck,
 		    ib.invoicenumber AS InvoiceNumber ,
 		    (SELECT t.name FROM team t INNER JOIN team2customer t2c ON t2c.teamoid = t.oid WHERE t2c.customeroid = c.Oid limit 1) AS TeamName,
-		    CASE WHEN ib.RecipientOrganisation LIKE '%Selbstzahler%' THEN 049030 ELSE 049020 END AS Erloeskonto,
+		    CASE WHEN ib.RecipientOrganisation LIKE '%Selbstzahler%' THEN '049030' ELSE '049020' END AS Erloeskonto,
 		    ib.AccountingPeriodEnd AS Periode,
 		    ib.Oid AS InvoiceOid
 		 FROM
@@ -182,7 +196,8 @@ namespace DiakonischesWerkRegensburg.Export
 		 INNER JOIN invoicebase ib ON ib.costbearer2supportconceptoid = c2s.oid
 		 INNER JOIN serviceinvoice si ON si.invoicebaseoid = ib.oid
 		 INNER JOIN serviceinvoiceperiod sip ON sip.serviceinvoiceoid = si.oid
-	    WHERE ib.`AccountingPeriodEnd` >= ':Monat_Start' AND ib.`AccountingPeriodEnd` < ':Monat_End' AND ib.IsActive = 1 AND ib.InvoiceId IS NULL AND ib.IsExported = 0 
+	    WHERE ib.`AccountingPeriodEnd` >= ':Monat_Start' AND ib.`AccountingPeriodEnd` < ':Monat_End' AND ib.IsActive = 1 AND ib.InvoiceId IS NULL AND ib.IsExported = 0
+	    GROUP BY ib.Oid, ib.InvoiceNumber, ib.InvoiceDate, ib.AccountingPeriodEnd, ib.RecipientOrganisation, c.Oid, c.DebitorNumber, p.LastName, p.FirstName
         ) t
     WHERE t.InvoiceOid IS NOT NULL
     ORDER BY t.invoicenumber