diff --git a/doc/BUSINESSPARTNER.md b/doc/BUSINESSPARTNER.md
index 507ad40..05c168e 100644
--- a/doc/BUSINESSPARTNER.md
+++ b/doc/BUSINESSPARTNER.md
@@ -68,3 +68,9 @@ Feldmühle
 
 - D14169
   K74169
+
+K76233 HSH Papier GmbH & Co. KG
+
+D16233 Manfred Ziegler Transport GmbH
+
+Problemkind: https://alexander-logistics-dwc.office-workflow.de/pages/workitems/workitem.xhtml?id=9dd64b0a-cfe1-4174-aea4-0e8af45b823f
diff --git a/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/InvoiceUtil.java b/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/InvoiceUtil.java
index e176474..a3eee3a 100644
--- a/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/InvoiceUtil.java
+++ b/office-alexander-logistics-app/src/main/java/com/alexanderlogistics/InvoiceUtil.java
@@ -169,6 +169,10 @@ public class InvoiceUtil {
      * @return
      */
     public static String buildBPID(String key) {
+        if (key == null || key.length() < 1) {
+            // no data
+            return key;
+        }
         key = key.toUpperCase();
         if (key.startsWith("D") || key.startsWith("K")) {
             key = key.substring(1);
@@ -189,7 +193,6 @@ public class InvoiceUtil {
      * @return
      */
     public static String getBPID(ItemCollection invoice) {
-
         if (isCreditorInvoice(invoice)) {
             // key ist cdtr.number
             return buildBPID(invoice.getItemValueString("cdtr.number"));