diff --git a/website_sale_slides_order_line_link/i18n/es.po b/website_sale_slides_order_line_link/i18n/es.po
new file mode 100644
index 0000000..6196781
--- /dev/null
+++ b/website_sale_slides_order_line_link/i18n/es.po
@@ -0,0 +1,69 @@
+# Translation of Odoo Server.
+# This file contains the translation of the following modules:
+# 	* website_sale_slides_order_line_link
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: Odoo Server 17.0\n"
+"Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: 2026-01-30 10:53+0000\n"
+"PO-Revision-Date: 2026-01-30 11:56+0100\n"
+"Last-Translator: \n"
+"Language-Team: \n"
+"Language: es\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+"X-Generator: Poedit 3.4.2\n"
+
+#. module: website_sale_slides_order_line_link
+#. odoo-python
+#: code:addons/website_sale_slides_order_line_link/models/sale_order.py:0
+#, python-format
+msgid ""
+"<p>Your registrations for the course <strong>%(course_name)s</strong> have "
+"been increased by <strong>%(added_qty)s registration(s)</strong>.</p><p>You "
+"now have a total of <strong>%(available_registrations)s</strong> "
+"registration(s) purchased, of which <strong>%(used_registrations)s</strong> "
+"have already been used and <strong>%(remaining_registrations)s</strong> are "
+"still available.</p>"
+msgstr ""
+"<p>Sus inscripciones para el curso <strong>%(course_name)s</strong> se han "
+"incrementado en <strong>%(added_qty)s inscripción(es)</strong>.</p><p>Ahora "
+"dispone de un total de <strong>%(available_registrations)s</strong> "
+"inscripción(es) adquiridas, de las cuales <strong>%(used_registrations)s</"
+"strong> ya se han utilizado y <strong>%(remaining_registrations)s</strong> "
+"siguen disponibles.</p>"
+
+#. module: website_sale_slides_order_line_link
+#: model:ir.model,name:website_sale_slides_order_line_link.model_slide_channel_partner
+msgid "Channel / Partners (Members)"
+msgstr ""
+
+#. module: website_sale_slides_order_line_link
+#. odoo-python
+#: code:addons/website_sale_slides_order_line_link/models/sale_order.py:0
+#, python-format
+msgid "Course Registrations Added: %s"
+msgstr "Inscripciones añadidas al curso: %s"
+
+#. module: website_sale_slides_order_line_link
+#: model:ir.model.fields,field_description:website_sale_slides_order_line_link.field_slide_channel_partner__sale_order_line_ids
+msgid "Sale Order Lines"
+msgstr "Líneas de pedido"
+
+#. module: website_sale_slides_order_line_link
+#: model:ir.model,name:website_sale_slides_order_line_link.model_sale_order
+msgid "Sales Order"
+msgstr ""
+
+#. module: website_sale_slides_order_line_link
+#: model:ir.model,name:website_sale_slides_order_line_link.model_sale_order_line
+msgid "Sales Order Line"
+msgstr ""
+
+#. module: website_sale_slides_order_line_link
+#: model:ir.model.fields,field_description:website_sale_slides_order_line_link.field_sale_order_line__slide_channel_partner_id
+msgid "Slide Channel Partner"
+msgstr ""
diff --git a/website_sale_slides_order_line_link/i18n/website_sale_slides_order_line_link.pot b/website_sale_slides_order_line_link/i18n/website_sale_slides_order_line_link.pot
index 3790ec2..f1097bf 100644
--- a/website_sale_slides_order_line_link/i18n/website_sale_slides_order_line_link.pot
+++ b/website_sale_slides_order_line_link/i18n/website_sale_slides_order_line_link.pot
@@ -6,6 +6,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: Odoo Server 17.0\n"
 "Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: 2026-01-30 10:53+0000\n"
+"PO-Revision-Date: 2026-01-30 10:53+0000\n"
 "Last-Translator: \n"
 "Language-Team: \n"
 "MIME-Version: 1.0\n"
@@ -13,11 +15,31 @@ msgstr ""
 "Content-Transfer-Encoding: \n"
 "Plural-Forms: \n"
 
+#. module: website_sale_slides_order_line_link
+#. odoo-python
+#: code:addons/website_sale_slides_order_line_link/models/sale_order.py:0
+#, python-format
+msgid ""
+"<p>Your registrations for the course <strong>%(course_name)s</strong> have "
+"been increased by <strong>%(added_qty)s registration(s)</strong>.</p><p>You "
+"now have a total of <strong>%(available_registrations)s</strong> "
+"registration(s) purchased, of which <strong>%(used_registrations)s</strong> "
+"have already been used and <strong>%(remaining_registrations)s</strong> are "
+"still available.</p>"
+msgstr ""
+
 #. module: website_sale_slides_order_line_link
 #: model:ir.model,name:website_sale_slides_order_line_link.model_slide_channel_partner
 msgid "Channel / Partners (Members)"
 msgstr ""
 
+#. module: website_sale_slides_order_line_link
+#. odoo-python
+#: code:addons/website_sale_slides_order_line_link/models/sale_order.py:0
+#, python-format
+msgid "Course Registrations Added: %s"
+msgstr ""
+
 #. module: website_sale_slides_order_line_link
 #: model:ir.model.fields,field_description:website_sale_slides_order_line_link.field_slide_channel_partner__sale_order_line_ids
 msgid "Sale Order Lines"
diff --git a/website_sale_slides_order_line_link/models/sale_order.py b/website_sale_slides_order_line_link/models/sale_order.py
index aded62e..816cf40 100644
--- a/website_sale_slides_order_line_link/models/sale_order.py
+++ b/website_sale_slides_order_line_link/models/sale_order.py
@@ -1,7 +1,8 @@
-# Copyright 2025 Tecnativa - Pilar Vargas
+# Copyright 2025-2026 Tecnativa - Pilar Vargas
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+from markupsafe import Markup
 
-from odoo import fields, models
+from odoo import _, fields, models
 
 
 class SaleOrder(models.Model):
@@ -12,11 +13,60 @@ def _action_confirm(self):
             lambda line: line.product_id.channel_ids
         )
         if course_lines:
+            for line in course_lines:
+                existing_parent = self.env["slide.channel.partner"].search(
+                    [
+                        ("channel_id", "in", line.product_id.channel_ids.ids),
+                        ("partner_id", "=", self.partner_id.id),
+                        ("sale_order_line_ids", "!=", False),
+                    ],
+                    limit=1,
+                )
+                if existing_parent:
+                    linked_lines_this_order = (
+                        existing_parent.sale_order_line_ids.filtered(
+                            lambda ln: ln.order_id.id == self.id
+                        )
+                    )
+                    commands = [(3, ln.id) for ln in linked_lines_this_order]
+                    commands.append((4, line.id))
+                    existing_parent.write({"sale_order_line_ids": commands})
+                    if not linked_lines_this_order:
+                        self._send_registrations_added_mail(
+                            line.product_uom_qty, existing_parent
+                        )
             return super(
                 SaleOrder, self.with_context(course_sale_order_lines=course_lines)
             )._action_confirm()
         return super()._action_confirm()
 
+    def _send_registrations_added_mail(self, added_qty, registration):
+        body = Markup(
+            _(
+                "<p>Your registrations for the course <strong>%(course_name)s</strong> "
+                "have been increased by <strong>%(added_qty)s registration(s)</strong>."
+                "</p>"
+                "<p>You now have a total of "
+                "<strong>%(available_registrations)s</strong> "
+                "registration(s) purchased, of which "
+                "<strong>%(used_registrations)s</strong> have already been used and "
+                "<strong>%(remaining_registrations)s</strong> are still available.</p>",
+                course_name=registration.channel_id.name,
+                added_qty=int(added_qty),
+                available_registrations=registration.available_registrations,
+                used_registrations=registration.used_registrations,
+                remaining_registrations=registration.remaining_registrations,
+            )
+        )
+        self.message_post(
+            body=body,
+            subject=_("Course Registrations Added: %s") % registration.channel_id.name,
+            message_type="comment",
+            subtype_xmlid="mail.mt_comment",
+            partner_ids=[self.partner_id.id],
+            email_layout_xmlid="mail.mail_notification_light",
+        )
+
 
 class SaleOrderLine(models.Model):
     _inherit = "sale.order.line"