diff --git a/BookAStar/BookAStar/Data/RemoteEntity.cs b/BookAStar/BookAStar/Data/RemoteEntity.cs
index 3a8119ed..666f594e 100644
--- a/BookAStar/BookAStar/Data/RemoteEntity.cs
+++ b/BookAStar/BookAStar/Data/RemoteEntity.cs
@@ -137,7 +137,7 @@ namespace BookAStar.Data
                     {
                         // TODO throw custom exception, and catch to inform user
                         var errcontent = await response.Content.ReadAsStringAsync();
-                        Debug.WriteLine($"Create failed posting {stringContent} @ {controllerUri.AbsoluteUri}");
+                        Debug.WriteLine($"Create failed posting {stringContent} @ {controllerUri.AbsoluteUri}: {errcontent}");
                     }
                     else
                     {
diff --git a/BookAStar/BookAStar/Interfaces/IEstimate.cs b/BookAStar/BookAStar/Interfaces/IEstimate.cs
index 6a21f114..ebe25cd1 100644
--- a/BookAStar/BookAStar/Interfaces/IEstimate.cs
+++ b/BookAStar/BookAStar/Interfaces/IEstimate.cs
@@ -5,9 +5,9 @@ namespace BookAStar.Model.Interfaces
 {
     public interface IEstimate
     {
-        IList<string> AttachedFiles { get; set; }
-        IList<string> AttachedGraphics { get; }
-        IList<BillingLine> Bill { get; set; }
+        List<string> AttachedFiles { get; set; }
+        List<string> AttachedGraphics { get; }
+        List<BillingLine> Bill { get; set; }
         string ClientId { get; set; }
         long? CommandId { get; set; }
         string CommandType { get; set; }
diff --git a/BookAStar/BookAStar/Model/Workflow/Estimate.cs b/BookAStar/BookAStar/Model/Workflow/Estimate.cs
index a2cb664e..c0c269a7 100644
--- a/BookAStar/BookAStar/Model/Workflow/Estimate.cs
+++ b/BookAStar/BookAStar/Model/Workflow/Estimate.cs
@@ -15,7 +15,7 @@ namespace BookAStar.Model.Workflow
         // Markdown expected
         public string Description { get; set; }
         public string Title { get; set; }
-        public IList<BillingLine> Bill { get; set; }
+        public List<BillingLine> Bill { get; set; }
         /// <summary>
         /// List of attached graphic files
         /// to this estimate, as relative pathes to
@@ -23,7 +23,7 @@ namespace BookAStar.Model.Workflow
         /// In db, they are separated by <c>:</c>
         /// </summary>
         /// <returns></returns>
-        public IList<string> AttachedGraphics { get; set; }
+        public List<string> AttachedGraphics { get; set; }
         [JsonIgnore]
         public string AttachedGraphicsString
         {
@@ -37,7 +37,7 @@ namespace BookAStar.Model.Workflow
         /// In db, they are separated by <c>:</c>
         /// </summary>
         /// <returns></returns>
-        public IList<string> AttachedFiles { get; set; }
+        public List<string> AttachedFiles { get; set; }
         [JsonIgnore]
         public string AttachedFilesString
         {
diff --git a/BookAStar/BookAStar/Pages/EditBillingLinePage.xaml b/BookAStar/BookAStar/Pages/EditBillingLinePage.xaml
index 6ce717aa..624909f4 100644
--- a/BookAStar/BookAStar/Pages/EditBillingLinePage.xaml
+++ b/BookAStar/BookAStar/Pages/EditBillingLinePage.xaml
@@ -39,9 +39,9 @@
 
     </ResourceDictionary>
   </ContentPage.Resources>
-    <ScrollView>
+  <ScrollView>
 
-  <StackLayout x:Name="mainStackLayout">
+    <StackLayout x:Name="mainStackLayout">
       <Label Text="Description de la ligne de facture"
              Style="{StaticResource InputLabelStyle}"></Label>
       <StackLayout Orientation="Horizontal" VerticalOptions="FillAndExpand">
@@ -93,12 +93,14 @@
                                 Path=IsValid, 
                                 Converter={StaticResource boolToStyleImage}}" />
       </StackLayout>
-        <Button Text="Términé"
+      <StackLayout Orientation="Horizontal">
+        <Button Text="Supprimer"
                     Command="{Binding DeleteCommand}"
-                    Clicked="OnValidateClicked"></Button>
+                    Clicked="OnDeleteClicked"></Button>
         <Button Text="Términé"
                 Command="{Binding ValidateCommand}"
                 Clicked="OnValidateClicked"></Button>
-  </StackLayout>
-    </ScrollView>
+      </StackLayout>
+    </StackLayout>
+  </ScrollView>
 </ContentPage>
diff --git a/BookAStar/BookAStar/Pages/EditBillingLinePage.xaml.cs b/BookAStar/BookAStar/Pages/EditBillingLinePage.xaml.cs
index 779d189e..0667afe1 100644
--- a/BookAStar/BookAStar/Pages/EditBillingLinePage.xaml.cs
+++ b/BookAStar/BookAStar/Pages/EditBillingLinePage.xaml.cs
@@ -16,7 +16,10 @@ namespace BookAStar.Pages
                 picker.Items.Add(du);
             BindingContext = model;
         }
-        
+        public void OnDeleteClicked(object sender, EventArgs e)
+        {
+            throw new NotImplementedException();
+        }
         public void OnValidateClicked (object sender, EventArgs e)
         {
             this.Navigation.PopAsync();
diff --git a/BookAStar/BookAStar/ViewModels/EditEstimateViewModel.cs b/BookAStar/BookAStar/ViewModels/EditEstimateViewModel.cs
index cef7746a..521851b9 100644
--- a/BookAStar/BookAStar/ViewModels/EditEstimateViewModel.cs
+++ b/BookAStar/BookAStar/ViewModels/EditEstimateViewModel.cs
@@ -31,7 +31,7 @@ namespace BookAStar.ViewModels
 
         private void Bill_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
         {
-            Data.Bill = Bill;
+            Data.Bill = new List<BillingLine>( Bill );
             NotifyPropertyChanged("FormattedTotal");
         }
         private Estimate data;