diff --git a/Shared/DataContracts/InvoiceBaseDC.cs b/Shared/DataContracts/InvoiceBaseDC.cs
index 679d87904..490e3433c 100644
--- a/Shared/DataContracts/InvoiceBaseDC.cs
+++ b/Shared/DataContracts/InvoiceBaseDC.cs
@@ -123,7 +123,7 @@ namespace BS.Shared.DataContracts
 			}
 		}
 
-		public IEnumerable<IInvoiceItem> IInvoiceItems => throw new NotImplementedException();
+		public IEnumerable<IInvoiceItem> IInvoiceItems => InvoiceItems;
 
 		public bool ContainsRecipientAddressData()
 		{
diff --git a/Shared/DataContracts/InvoiceItemDC.cs b/Shared/DataContracts/InvoiceItemDC.cs
index 254c2123e..daa62924f 100644
--- a/Shared/DataContracts/InvoiceItemDC.cs
+++ b/Shared/DataContracts/InvoiceItemDC.cs
@@ -8,7 +8,7 @@ namespace BS.Shared.DataContracts
 {
     [DataContract]
     [DebuggerDisplay("{ItemDescription}: {AmountPerUnit} x {UnitCount} = {AmountTotal}")]
-    public class InvoiceItemDC : IDataContract
+    public class InvoiceItemDC : IDataContract, IInvoiceItem
     {
         
         [DataMember]