diff --git a/addons/delivery/models/sale_order.py b/addons/delivery/models/sale_order.py
index 10ef58973d5..cd09c8490ab 100644
--- a/addons/delivery/models/sale_order.py
+++ b/addons/delivery/models/sale_order.py
@@ -43,10 +43,7 @@ class SaleOrder(models.Model):
         self._remove_delivery_line()
 
         for order in self:
-            if order.state not in ('draft', 'sent'):
-                raise UserError(_('You can add delivery price only on unconfirmed quotations.'))
-            else:
-                order._create_delivery_line(carrier, amount, price_unit_in_description=self.carrier_id.invoice_policy == 'real')
+            order._create_delivery_line(carrier, amount, price_unit_in_description=self.carrier_id.invoice_policy == 'real')
         return True
 
     def action_open_delivery_wizard(self):
@@ -66,7 +63,8 @@ class SaleOrder(models.Model):
         }
 
     def recompute_delivery_cost(self):
-        delivery_line = self.order_line.filtered('is_delivery')
+        self.ensure_one()
+        delivery_line = self.order_line.filtered('is_delivery')[:1]
         res = self.carrier_id.rate_shipment(self)
         if res.get('success'):
             self.delivery_message = res.get('warning_message', False)
diff --git a/addons/delivery/views/delivery_view.xml b/addons/delivery/views/delivery_view.xml
index 4e5423b6f4f..85075d13ab4 100644
--- a/addons/delivery/views/delivery_view.xml
+++ b/addons/delivery/views/delivery_view.xml
@@ -308,20 +308,20 @@
                                 string="Add a shipping method"
                                 name="action_open_delivery_wizard"
                                 type="object"
-                                attrs="{'invisible': ['|', '|', ('order_line', '=', []), ('delivery_set', '=', True), ('state', 'not in', ('draft', 'sent'))]}"
+                                attrs="{'invisible': ['|', ('order_line', '=', []), ('delivery_set', '=', True)]}"
                             />
                             <button
                                 string="Recompute shipping cost"
                                 name="recompute_delivery_cost"
                                 type="object"
                                 class="text-warning btn-secondary"
-                                attrs="{'invisible': ['|', '|', ('recompute_delivery_price', '=', False), ('delivery_set', '=', False), ('state', 'not in', ('draft', 'sent'))]}"
+                                attrs="{'invisible': ['|', ('recompute_delivery_price', '=', False), ('delivery_set', '=', False)]}"
                             />
                             <button
                                 string="Recompute shipping cost"
                                 name="recompute_delivery_cost"
                                 type="object"
-                                attrs="{'invisible': ['|', '|', ('recompute_delivery_price', '=', True), ('delivery_set', '=', False), ('state', 'not in', ('draft', 'sent'))]}"
+                                attrs="{'invisible': ['|', ('recompute_delivery_price', '=', True), ('delivery_set', '=', False)]}"
                             />
                         </div>
                     </xpath>