diff --git a/modules/ticket/back/methods/sale/updateDiscount.js b/modules/ticket/back/methods/sale/updateDiscount.js
index 1c1db1927..e1793241b 100644
--- a/modules/ticket/back/methods/sale/updateDiscount.js
+++ b/modules/ticket/back/methods/sale/updateDiscount.js
@@ -1,7 +1,7 @@
 let UserError = require('vn-loopback/util/user-error');
 
 module.exports = Self => {
-    Self.remoteMethod('updateDiscount', {
+    Self.remoteMethodCtx('updateDiscount', {
         description: 'Changes the discount of a sale',
         accessType: '',
         accepts: [{
@@ -21,16 +21,12 @@ module.exports = Self => {
         }
     });
 
-    Self.updateDiscount = async params => {
+    Self.updateDiscount = async(ctx, params) => {
         if (isNaN(params.editLines[0].discount))
             throw new UserError(`The value should be a number`);
 
         let model = Self.app.models;
         let thisTicketIsEditable = await model.Ticket.isEditable(params.editLines[0].ticketFk);
-
-        if (!thisTicketIsEditable)
-            throw new UserError(`The sales of this ticket can't be modified`);
-
         let ticket = await model.Ticket.find({
             where: {
                 id: params.editLines[0].ticketFk
@@ -41,9 +37,16 @@ module.exports = Self => {
                     fields: ['salesPersonFk']
                 }
             }],
-            fields: ['id', 'clientFk']
+            fields: ['id', 'clientFk', 'refFk']
         });
 
+        let userId = ctx.req.accessToken.userId;
+        let isSalesAssistant = await Self.app.models.Account.hasRole(userId, 'salesAssistant');
+
+        if ((!thisTicketIsEditable && !isSalesAssistant) || (ticket.refFk && isSalesAssistant))
+            throw new UserError(`The sales of this ticket can't be modified`);
+
+
         let componentToUse;
         let usesMana = await model.WorkerMana.findOne({where: {workerFk: ticket[0].client().salesPersonFk}, fields: 'amount'});