diff --git a/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/datev/DatevCargosoftImportAdapter.java b/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/datev/DatevCargosoftImportAdapter.java
index 557905b..7bb06ea 100644
--- a/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/datev/DatevCargosoftImportAdapter.java
+++ b/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/datev/DatevCargosoftImportAdapter.java
@@ -25,6 +25,7 @@ import org.imixs.workflow.exceptions.AdapterException;
 import org.imixs.workflow.exceptions.ModelException;
 import org.imixs.workflow.exceptions.PluginException;
 import org.imixs.workflow.exceptions.ProcessingErrorException;
+import org.imixs.workflow.exceptions.QueryException;
 
 import com.alexanderlogistics.KreditorDebitorService;
 
@@ -68,7 +69,8 @@ public class DatevCargosoftImportAdapter implements SignalAdapter {
 
         logger.info("...parse datev file import...");
         try {
-            readData(workitem);
+            List<String> log = readData(workitem);
+            workitem.setItemValue("import.log", log);
         } catch (ModelException e) {
             throw new AdapterException(PluginException.class.getSimpleName(), DatevImportAdapter.DATEV_IMPORT_ERROR,
                     "Failed to import datev data!", e);
@@ -91,21 +93,27 @@ public class DatevCargosoftImportAdapter implements SignalAdapter {
      * @throws ProcessingErrorException
      * @throws AccessDeniedException
      */
-    private void readData(ItemCollection workitem)
+    private List<String> readData(ItemCollection workitem)
             throws PluginException, AccessDeniedException, ProcessingErrorException, ModelException {
+        List<String> logBuffer = new ArrayList<String>();
+        int line = 0;
+        int positions = 0;
+        int invoices = 0;
+        int dupplicates = 0;
+       
         String dataLine;
         // Start Datum Wirtschaftsjahr berechnen (JJJJMMTT)
-        String wjBeginn=workitem.getItemValueString("datev.WJ-Beginn");
-        String wjBeginnMonat=wjBeginn.substring(4,6);
+        String wjBeginn = workitem.getItemValueString("datev.WJ-Beginn");
+        String wjBeginnMonat = wjBeginn.substring(4, 6);
         SimpleDateFormat dateFormatter = new SimpleDateFormat("yyyyMMdd");
 
-        
         ItemCollection invoiceWorkitem = null;
         List<ItemCollection> splitBuchungen = new ArrayList<ItemCollection>();
 
         FileData fileData = workitem.getFileData().get(0);
         ByteArrayInputStream imputStream = new ByteArrayInputStream(fileData.getContent());
 
+        log(logBuffer, "Importdatei: " + fileData.getName());
         try {
             BufferedReader in = new BufferedReader(new InputStreamReader(imputStream, ENCODING));
 
@@ -114,7 +122,7 @@ public class DatevCargosoftImportAdapter implements SignalAdapter {
             in.readLine();
 
             // read content....
-            int line = 0;
+            line = 0;
             int blockSize = 0;
             while ((dataLine = in.readLine()) != null) {
                 line++;
@@ -126,8 +134,8 @@ public class DatevCargosoftImportAdapter implements SignalAdapter {
                 // alle werte parsen
                 String[] header1List = dataLine.split(";(?=([^\"]*\"[^\"]*\")*[^\"]*$)", 99);
                 if (header1List.length < 6) {
-                    throw new PluginException(DatevCargosoftImportAdapter.class.getName(),DatevImportAdapter.DATEV_IMPORT_ERROR,
-                            "Invalid data in line " + line);
+                    throw new PluginException(DatevCargosoftImportAdapter.class.getName(),
+                            DatevImportAdapter.DATEV_IMPORT_ERROR, "Invalid data in line " + line);
                 }
 
                 String belegNummer = DatevImportAdapter.csvVal(header1List[10]);
@@ -135,36 +143,36 @@ public class DatevCargosoftImportAdapter implements SignalAdapter {
                 String text = DatevImportAdapter.csvVal(header1List[13]);
                 String buchungsTag = DatevImportAdapter.csvVal(header1List[9]);
                 // cargosoft laesst gerne die führende 0 weg....
-                if (buchungsTag.length()==3) {
-                    buchungsTag="0"+buchungsTag;
+                if (buchungsTag.length() == 3) {
+                    buchungsTag = "0" + buchungsTag;
                 }
                 // berechne Buchungsdatum DDMM
-                String tag=buchungsTag.substring(0,2);
-                String monat=buchungsTag.substring(2,4);
-                String jahr=wjBeginn.substring(0,4); 
+                String tag = buchungsTag.substring(0, 2);
+                String monat = buchungsTag.substring(2, 4);
+                String jahr = wjBeginn.substring(0, 4);
                 // compute next year if start of WJ is not January
-                if (Integer.parseInt(wjBeginnMonat)>Integer.parseInt(monat)) {
-                    jahr=Integer.parseInt(jahr+1)+"";
+                if (Integer.parseInt(wjBeginnMonat) > Integer.parseInt(monat)) {
+                    jahr = Integer.parseInt(jahr + 1) + "";
                 }
-                Date dateBuchung = dateFormatter.parse(jahr+monat+tag);
+                Date dateBuchung = dateFormatter.parse(jahr + monat + tag);
                 // Fälligkeit
-                Date dueDate=dateFormatter.parse(DatevImportAdapter.csvVal(header1List[23]));
-                String paymentTerm= DatevImportAdapter.csvVal(header1List[31]);
+                Date dueDate = dateFormatter.parse(DatevImportAdapter.csvVal(header1List[23]));
+                String paymentTerm = DatevImportAdapter.csvVal(header1List[31]);
                 String waehrung = DatevImportAdapter.csvVal(header1List[2]);
-                
+
                 // kurse
-                double kurs=parseBetrag(DatevImportAdapter.csvVal(header1List[3]));
-                double basisumsatz= parseBetrag(DatevImportAdapter.csvVal(header1List[4]));
-                
+                double kurs = parseBetrag(DatevImportAdapter.csvVal(header1List[3]));
+                double basisumsatz = parseBetrag(DatevImportAdapter.csvVal(header1List[4]));
+
                 // Skip Eingangsrechnungen
                 if (!gegenKonto.startsWith("1")) {
                     // skip
                     continue;
                 }
 
-                
-                logger.info("...read dbtr: "  + gegenKonto + " beleg-nr: "+belegNummer);
-                
+                positions++;
+                logger.info("...read dbtr: " + gegenKonto + " beleg-nr: " + belegNummer);
+
                 // Erzeuge einen Buchungssatz
                 ItemCollection dataItemCol = new ItemCollection();
                 dataItemCol.setItemValue("datev.text", text);
@@ -174,16 +182,19 @@ public class DatevCargosoftImportAdapter implements SignalAdapter {
                 dataItemCol.setItemValue("datev.kurs", parseBetrag(DatevImportAdapter.csvVal(header1List[3])));
                 dataItemCol.setItemValue("datev.basisumsatz", parseBetrag(DatevImportAdapter.csvVal(header1List[4])));
                 dataItemCol.setItemValue("datev.konto", DatevImportAdapter.csvVal(header1List[6]));
-                
-                
-                 
-
 
                 // Haben wir schon eine Invoice Workitem angelegt?
                 if (invoiceWorkitem == null) {
                     logger.info("...create new workitem....");
                     // erzeuge ein neues
-                    invoiceWorkitem =createEmptyInvoice(belegNummer,text,gegenKonto,dateBuchung,dueDate,paymentTerm,waehrung,kurs,basisumsatz );
+                    try {
+                        invoiceWorkitem = createEmptyInvoice(belegNummer, text, gegenKonto, dateBuchung, dueDate,
+                                paymentTerm, waehrung, kurs, basisumsatz);
+                        invoices++;
+                    } catch (AdapterException e) {
+                        dupplicates++;
+                        continue;
+                    }
                 }
 
                 // ist es noch die selbe Belegnummer?
@@ -193,47 +204,100 @@ public class DatevCargosoftImportAdapter implements SignalAdapter {
                     logger.info("...add splitbuchung....");
                 } else {
                     logger.info("...close workitem....");
-                   
+
                     // nein - also invoice schließen
                     closeInvoiceWorkitem(invoiceWorkitem, splitBuchungen);
-
+                    invoiceWorkitem=null;
                     // neue Splitbuchungstabelle anlegen
                     splitBuchungen = new ArrayList<ItemCollection>();
                     // invoice zurücksetzten
                     // erzeuge ein neues
-                    invoiceWorkitem =createEmptyInvoice(belegNummer,text,gegenKonto,dateBuchung,dueDate,paymentTerm,waehrung,kurs,basisumsatz );
+                    try {
+                        invoiceWorkitem = createEmptyInvoice(belegNummer, text, gegenKonto, dateBuchung, dueDate,
+                                paymentTerm, waehrung, kurs, basisumsatz);
+                        invoices++;
+                    } catch (AdapterException e) {
+                        dupplicates++;
+                        continue;
+                    }
                     splitBuchungen.add(dataItemCol);
                 }
 
-            }// wile end
-            closeInvoiceWorkitem(invoiceWorkitem,splitBuchungen);
+            } // wile end
+            closeInvoiceWorkitem(invoiceWorkitem, splitBuchungen);
 
         } catch (IOException | ParseException e) {
-            throw new PluginException(DatevCargosoftImportAdapter.class.getName(), DatevImportAdapter.DATEV_IMPORT_ERROR,
-                    "Unable to read file", e);
+            throw new PluginException(DatevCargosoftImportAdapter.class.getName(),
+                    DatevImportAdapter.DATEV_IMPORT_ERROR, "Unable to read file", e);
         }
 
+        log(logBuffer, line + " Zeilen eingelesen ");
+        log(logBuffer, positions + " Rechnungspositionen eingelesen ");
+        log(logBuffer, invoices + " Rechnungen importiert ");
+        if (dupplicates > 0) {
+            log(logBuffer, dupplicates + " Rechnungen wurden übersprungen da diese bereits importiert wurden!");
+        }
+
+        // return log
+        return logBuffer;
+
     }
 
-    private ItemCollection createEmptyInvoice(String belegNummer, String text, String gegenKonto, Date dateBuchung,Date dueDate,String paymentTerm,String currency,
-            double kurs,double basisUmsatz) {
+    /**
+     * This method returns a new empty invoice ItemCollection.
+     * <p>
+     * The method tests if an invoice with this number already exits. If so, the
+     * method throws a AdapterException
+     * 
+     * @param belegNummer
+     * @param text
+     * @param gegenKonto
+     * @param dateBuchung
+     * @param dueDate
+     * @param paymentTerm
+     * @param currency
+     * @param kurs
+     * @param basisUmsatz
+     * @return
+     * @throws AdapterException
+     */
+    private ItemCollection createEmptyInvoice(String belegNummer, String text, String gegenKonto, Date dateBuchung,
+            Date dueDate, String paymentTerm, String currency, double kurs, double basisUmsatz)
+            throws AdapterException {
+
+        // test if invoice was already imported before
+        String sQuery = "((type:workitem OR type:workitemarchive) AND $modelversion:rechnungsausgang* AND invoice.number:\""+belegNummer+"\")";
+        try {
+            // find the textblock...
+            List<ItemCollection> result = documentService.find(sQuery, 1, 0);
+            if (result.size() > 0) {
+                throw new AdapterException(DatevCargosoftImportAdapter.class.getName(), "DUPPLICATE",
+                        "Invoice already imported");
+            }
+        } catch (QueryException e) {
+            logger.warning("failed to search invoices by query: " + e.getMessage());
+        }
+
         ItemCollection invoiceWorkitem = new ItemCollection();
         invoiceWorkitem.setItemValue("invoice.number", belegNummer);
-        invoiceWorkitem.setItemValue("invoice.currency", currency);        
+        invoiceWorkitem.setItemValue("invoice.currency", currency);
         invoiceWorkitem.setItemValue("invoice.text", text);
         invoiceWorkitem.setItemValue("invoice.date", dateBuchung);
         invoiceWorkitem.setItemValue("dbtr.number", gegenKonto);
-        invoiceWorkitem.setItemValue("invoice.duedate",dueDate);
+        invoiceWorkitem.setItemValue("invoice.duedate", dueDate);
         invoiceWorkitem.setItemValue("invoice.reminder", dueDate);
-        invoiceWorkitem.setItemValue("payment.term",paymentTerm);
-        
-        
-        invoiceWorkitem.setItemValue("invoice.rate",kurs);
-        invoiceWorkitem.setItemValue("invoice.base.amount",basisUmsatz);
-        
+        invoiceWorkitem.setItemValue("payment.term", paymentTerm);
+
+        invoiceWorkitem.setItemValue("invoice.rate", kurs);
+        invoiceWorkitem.setItemValue("invoice.base.amount", basisUmsatz);
+
         return invoiceWorkitem;
     }
 
+    private void log(List<String> log, String message) {
+        log.add(new Date() + ": " + message+"\n");
+    }
+
     /**
      * . entfernen , mit punkt ersetzten
      * 
diff --git a/office-alexander-logistics-app/src/main/webapp/pages/workitems/forms/import_log.xhtml b/office-alexander-logistics-app/src/main/webapp/pages/workitems/forms/import_log.xhtml
new file mode 100644
index 0000000..9a5bf48
--- /dev/null
+++ b/office-alexander-logistics-app/src/main/webapp/pages/workitems/forms/import_log.xhtml
@@ -0,0 +1,27 @@
+<ui:composition xmlns="http://www.w3.org/1999/xhtml"
+	xmlns:ui="http://java.sun.com/jsf/facelets"
+	xmlns:f="http://java.sun.com/jsf/core"
+	xmlns:c="http://java.sun.com/jsp/jstl/core"
+	xmlns:h="http://java.sun.com/jsf/html">
+
+
+
+	<h:panelGroup styleClass="imixs-form-section" id="import-log">
+
+		<h3>Protokoll:</h3>
+
+		
+		<ui:repeat value="#{workitem.itemList['import.log']}" var="entry">
+			<h:outputText value="#{entry}" />
+			<br />
+		</ui:repeat>
+		
+
+
+	</h:panelGroup>
+
+
+
+
+</ui:composition>
+
diff --git a/workflow/datev-import-1.0.0.bpmn b/workflow/datev-import-1.0.0.bpmn
index e4fad31..3f54169 100644
--- a/workflow/datev-import-1.0.0.bpmn
+++ b/workflow/datev-import-1.0.0.bpmn
@@ -165,7 +165,7 @@ result.isValid=true;
           <imixs:value><![CDATA[typcn-download-outline||typcn-tick,imixs-success]]></imixs:value>
         </imixs:item>
         <imixs:item name="txteditorid" type="xs:string">
-          <imixs:value><![CDATA[form_basic]]></imixs:value>
+          <imixs:value><![CDATA[form_basic#import_log]]></imixs:value>
         </imixs:item>
         <imixs:item name="txttype" type="xs:string">
           <imixs:value><![CDATA[workitemarchive]]></imixs:value>
@@ -232,7 +232,7 @@ if (workitem['$file.count'][0]!=1) {
           <imixs:value><![CDATA[DATEV-Import <itemvalue format="EEEE, d. MMMM yyyy" locale="de_DE">$created</itemvalue>]]></imixs:value>
         </imixs:item>
         <imixs:item name="txteditorid" type="xs:string">
-          <imixs:value><![CDATA[form_basic]]></imixs:value>
+          <imixs:value><![CDATA[form_basic#import_log]]></imixs:value>
         </imixs:item>
         <imixs:item name="txtimageurl" type="xs:string">
           <imixs:value><![CDATA[typcn-download-outline||||]]></imixs:value>
@@ -277,7 +277,7 @@ if (workitem['$file.count'][0]!=1) {
           <imixs:value><![CDATA[typcn-download-outline||typcn-times,imixs-error]]></imixs:value>
         </imixs:item>
         <imixs:item name="txteditorid" type="xs:string">
-          <imixs:value><![CDATA[form_basic]]></imixs:value>
+          <imixs:value><![CDATA[form_basic#import_log]]></imixs:value>
         </imixs:item>
         <imixs:item name="txttype" type="xs:string">
           <imixs:value><![CDATA[workitemarchive]]></imixs:value>
@@ -318,7 +318,7 @@ if (workitem['$file.count'][0]!=1) {
           <imixs:value><![CDATA[typcn-download-outline||typcn-time,imixs-warning]]></imixs:value>
         </imixs:item>
         <imixs:item name="txteditorid" type="xs:string">
-          <imixs:value><![CDATA[form_basic]]></imixs:value>
+          <imixs:value><![CDATA[form_basic#import_log]]></imixs:value>
         </imixs:item>
         <imixs:item name="txttype" type="xs:string">
           <imixs:value><![CDATA[workitem]]></imixs:value>