diff --git a/app/domain/booking_states/payment_due.rb b/app/domain/booking_states/payment_due.rb
index 532a3e90b..7dd58aae7 100644
--- a/app/domain/booking_states/payment_due.rb
+++ b/app/domain/booking_states/payment_due.rb
@@ -23,9 +23,9 @@ def self.to_sym
       invoice = booking.invoices.sent.kept.unsettled.ordered.last
       next if invoice.blank?
 
-      payable_until = invoice.payable_until + booking.organisation.settings.payment_overdue_deadline
+      payable_until = invoice.payable_until&.+(booking.organisation.settings.payment_overdue_deadline)
       postponable_for = booking.organisation.settings.deadline_postponable_for
-      booking.deadlines.create(at: payable_until, postponable_for:) unless booking.deadline
+      booking.deadlines.create(at: payable_until, postponable_for:) if payable_until.present? && !booking.deadline
     end
 
     infer_transition(to: :payment_overdue) do |booking|
diff --git a/app/models/tarifs/price.rb b/app/models/tarifs/price.rb
index 536962523..092b3b052 100644
--- a/app/models/tarifs/price.rb
+++ b/app/models/tarifs/price.rb
@@ -44,7 +44,7 @@ class Price < Tarif
     Tarif.register_subtype self
 
     def unit
-      organisation.currency
+      super || organisation.currency
     end
 
     def breakdown(usage)
diff --git a/app/services/export/pdf/contract_pdf.rb b/app/services/export/pdf/contract_pdf.rb
index d8adec426..8da444029 100644
--- a/app/services/export/pdf/contract_pdf.rb
+++ b/app/services/export/pdf/contract_pdf.rb
@@ -57,7 +57,8 @@ def tarif_table_data
         [[Tarif.model_name.human, Tarif.human_attribute_name(:unit), Tarif.human_attribute_name(:price_per_unit)]] +
           @contract.usages.map do |usage|
             tarif = usage.tarif
-            [tarif.label, tarif.unit, number_to_currency(usage.price_per_unit || 0, unit: @organisation.currency)]
+            price_per_unit = usage.price_per_unit || usage.price || 0
+            [tarif.label, tarif.unit, number_to_currency(price_per_unit, unit: @organisation.currency)]
           end
       end
     end
diff --git a/app/views/manage/invoices/index.html.slim b/app/views/manage/invoices/index.html.slim
index 0433f253e..a332637aa 100644
--- a/app/views/manage/invoices/index.html.slim
+++ b/app/views/manage/invoices/index.html.slim
@@ -90,9 +90,8 @@
                     - unless invoice.is_a?(Invoices::LateNotice)
                       = link_to new_manage_booking_invoice_path(invoice.booking, invoice: { type: Invoices::LateNotice, supersede_invoice_id: invoice.to_param }), class: 'btn btn-default' do
                         = Invoices::LateNotice.model_name.human
-                    - unless invoice.sent?
-                      = link_to edit_manage_invoice_path(invoice), class: 'btn btn-default' do
-                        span.fa.fa-edit
+                  = link_to edit_manage_invoice_path(invoice), class: "btn btn-default #{invoice.sent? ? 'disabled text-muted' : ''} border-0 p-2" do
+                    span.fa.fa-edit
                   = link_to manage_invoice_path(invoice), data: { confirm: t(:confirm) }, method: :delete, class: 'btn btn-default' do
                     span.fa.fa-trash
 
diff --git a/app/views/manage/occupancies/index.html.slim b/app/views/manage/occupancies/index.html.slim
index 3b563b497..ef641c709 100644
--- a/app/views/manage/occupancies/index.html.slim
+++ b/app/views/manage/occupancies/index.html.slim
@@ -42,7 +42,7 @@ h1.m-0= Occupancy.model_name.human(count: 2)
                 = link_to manage_occupancy_path(occupancy), data: { confirm: t(:confirm) }, method: :delete, class: 'btn btn-default' , title: t(:destroy) do
                   span.fa.fa-trash
               - else
-                button.btn.btn-default[disabled]
+                button.btn.btn-default.border-0.text-muted[disabled]
                   span.fa.fa-trash
 
 br