diff --git a/ReportImp/LyvieKupfer/Invoicing/CustomInvoiceCreation.cs b/ReportImp/LyvieKupfer/Invoicing/CustomInvoiceCreation.cs
new file mode 100644
index 000000000..83e02e429
--- /dev/null
+++ b/ReportImp/LyvieKupfer/Invoicing/CustomInvoiceCreation.cs
@@ -0,0 +1,24 @@
+using BeWo.Data.Entities;
+using BeWo.Service.Invoicing;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace LyvieKupfer.Invoicing
+{
+    public class CustomInvoiceCreation : InvoiceCreation
+    {
+        public override string GetSummaryItemKey(SupportConceptApprovalPeriod scap, InvoiceItem iitem, bool summaryPerMonth)
+        {
+            String key = String.Format("{0:0.0000}_{1}_{2}", iitem.AmountPerUnit, iitem.RateFactor, iitem.ItemDescription);
+            if (summaryPerMonth)
+            {
+                key = String.Format("{0:0.0000}_{1}_{2:yyyyMM}_{3}", iitem.AmountPerUnit, iitem.RateFactor, iitem.ItemPeriodStart, iitem.ItemDescription);
+            }
+
+            return key;
+        }
+    }
+}
diff --git a/ReportImp/LyvieKupfer/Invoicing/CustomInvoiceFactory.cs b/ReportImp/LyvieKupfer/Invoicing/CustomInvoiceFactory.cs
index 594ad83ae..ee5585373 100644
--- a/ReportImp/LyvieKupfer/Invoicing/CustomInvoiceFactory.cs
+++ b/ReportImp/LyvieKupfer/Invoicing/CustomInvoiceFactory.cs
@@ -17,7 +17,7 @@ namespace LyvieKupfer.Invoicing
 					return new CollectiveInvoiceCreation();
 				}
 			}
-			return new InvoiceCreation();
+			return new CustomInvoiceCreation();
 		}
 	}
 }
diff --git a/ReportImp/LyvieKupfer/LyvieKupfer.csproj b/ReportImp/LyvieKupfer/LyvieKupfer.csproj
index a5ab8481c..30b219163 100644
--- a/ReportImp/LyvieKupfer/LyvieKupfer.csproj
+++ b/ReportImp/LyvieKupfer/LyvieKupfer.csproj
@@ -57,6 +57,7 @@
   <ItemGroup>
     <Compile Include="Calculations\CustomGroupDurationCalculator.cs" />
     <Compile Include="Invoicing\CollectiveInvoiceCreation.cs" />
+    <Compile Include="Invoicing\CustomInvoiceCreation.cs" />
     <Compile Include="Invoicing\CustomInvoiceFactory.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Quittierungsbeleg.cs">