diff --git a/BeWo/ViewModel/InvoiceBaseVM.cs b/BeWo/ViewModel/InvoiceBaseVM.cs
index dda1041d1..5f82e70ef 100644
--- a/BeWo/ViewModel/InvoiceBaseVM.cs
+++ b/BeWo/ViewModel/InvoiceBaseVM.cs
@@ -921,6 +921,8 @@ namespace BeWo.ViewModel
 		public string SenderTown => DataContract.SenderTown;
 		public string SenderPostCode => DataContract.SenderPostCode;
 
+		public IList<IInvoiceItem> IInvoiceItems => throw new NotImplementedException();
+
 		protected override void InitByDataContract(InvoiceBaseDC pDataContract)
 		{
 			_SupportConceptOid = pDataContract.SupportConceptOid;
diff --git a/Shared/DataContracts/InvoiceBaseDC.cs b/Shared/DataContracts/InvoiceBaseDC.cs
index ef00aa5b9..e74398c6c 100644
--- a/Shared/DataContracts/InvoiceBaseDC.cs
+++ b/Shared/DataContracts/InvoiceBaseDC.cs
@@ -123,6 +123,8 @@ namespace BS.Shared.DataContracts
 			}
 		}
 
+		public IList<IInvoiceItem> IInvoiceItems => throw new NotImplementedException();
+
 		public bool ContainsRecipientAddressData()
 		{
 			return !Utils.AreAllNullOrEmpty(this.RecipientStreet, this.RecipientPostCode, this.RecipientTown);