diff --git a/pos_receipt_replace_user_by_trigram/__manifest__.py b/pos_receipt_replace_user_by_trigram/__manifest__.py
index d636b55c5b..1f736c2100 100644
--- a/pos_receipt_replace_user_by_trigram/__manifest__.py
+++ b/pos_receipt_replace_user_by_trigram/__manifest__.py
@@ -12,7 +12,6 @@
     "version": "16.0.1.0.0",
     "depends": [
         "point_of_sale",
-        "partner_firstname",
     ],
     "assets": {
         "point_of_sale.assets": [
@@ -22,6 +21,7 @@
         ],
     },
     "data": [
+        "data/ir_cron.xml",
         "views/res_config_settings.xml",
         "views/res_users.xml",
     ],
diff --git a/pos_receipt_replace_user_by_trigram/data/ir_cron.xml b/pos_receipt_replace_user_by_trigram/data/ir_cron.xml
new file mode 100644
index 0000000000..a063ee2f83
--- /dev/null
+++ b/pos_receipt_replace_user_by_trigram/data/ir_cron.xml
@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<odoo noupdate="1">
+    <record forcecreate="True" id="ir_cron_generate_pos_trigram" model="ir.cron">
+        <field name="name">POS: generate user trigram</field>
+        <field name="model_id" ref="base.model_res_partner" />
+        <field name="state">code</field>
+        <field eval="False" name="active" />
+        <field name="user_id" ref="base.user_root" />
+        <field name="interval_number">1</field>
+        <field name="interval_type">hours</field>
+        <field name="numbercall">1</field>
+        <field name="code">
+def get_trigram(*args):
+  valid = [x.strip() for x in args if x and x.strip()]
+  if valid:
+    if len(valid) &gt; 1:
+      trigram = valid[0][:1] + valid[1][:2]
+    else:
+      trigram = valid[0][:3]
+  else:
+    trigram = ""
+  return trigram
+
+partners = model.search([('pos_trigram', '=', ''), ('user_ids', '=', True)])
+for partner in partners:
+  firstname, lastname = partner.split(' ', 1)
+  partner.write({'pos_trigram': get_trigram(firstname, lastname)})
+</field>
+    </record>
+</odoo>
diff --git a/pos_receipt_replace_user_by_trigram/models/res_partner.py b/pos_receipt_replace_user_by_trigram/models/res_partner.py
index 0dbf51dbf2..b6d7468fa1 100644
--- a/pos_receipt_replace_user_by_trigram/models/res_partner.py
+++ b/pos_receipt_replace_user_by_trigram/models/res_partner.py
@@ -1,17 +1,10 @@
 # Copyright 2024 Camptocamp SA
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
 
-from odoo import api, fields, models
-
-from .. import utils
+from odoo import fields, models
 
 
 class ResPartner(models.Model):
     _inherit = "res.partner"
 
-    pos_trigram = fields.Char(compute="_compute_pos_trigram")
-
-    @api.depends("firstname", "lastname")
-    def _compute_pos_trigram(self):
-        for partner in self:
-            partner.pos_trigram = utils.get_trigram(partner.firstname, partner.lastname)
+    pos_trigram = fields.Char(tracking=True)
diff --git a/pos_receipt_replace_user_by_trigram/readme/CONFIGURE.rst b/pos_receipt_replace_user_by_trigram/readme/CONFIGURE.rst
index 35d761e5d7..2d1843aa76 100644
--- a/pos_receipt_replace_user_by_trigram/readme/CONFIGURE.rst
+++ b/pos_receipt_replace_user_by_trigram/readme/CONFIGURE.rst
@@ -2,3 +2,5 @@ By default, username on receipts is replaced by his Trigram.
 
 In "Point of Sale" configuration "Bills & Receipts" section, you can deactivate "Replace User by trigram in POS receipt" feature:
   .. image:: ../static/img/pos_config.png
+
+Generation of trigram is done through scheduled action 'POS: generate user trigram' that can be customized and executed manually.
diff --git a/pos_receipt_replace_user_by_trigram/tests/__init__.py b/pos_receipt_replace_user_by_trigram/tests/__init__.py
deleted file mode 100644
index 97355089d7..0000000000
--- a/pos_receipt_replace_user_by_trigram/tests/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-from . import test_get_trigram
diff --git a/pos_receipt_replace_user_by_trigram/tests/test_get_trigram.py b/pos_receipt_replace_user_by_trigram/tests/test_get_trigram.py
deleted file mode 100644
index 34e1a80978..0000000000
--- a/pos_receipt_replace_user_by_trigram/tests/test_get_trigram.py
+++ /dev/null
@@ -1,27 +0,0 @@
-from odoo.tests.common import TransactionCase
-
-from .. import utils
-
-
-class TestUtils(TransactionCase):
-    def test_get_trigram(self):
-        """
-        extract 1 letter from firstname and 2 letters from lastname
-        - If one of the fields is empty, extract 3 letters from the other field
-        - If both fields are empty, return an empty string
-        """
-        firstname = "Tri"
-        lastname = "Doan"
-        self.assertEqual(utils.get_trigram(firstname, lastname), "TDo")
-
-        firstname = ""
-        lastname = "Doan"
-        self.assertEqual(utils.get_trigram(firstname, lastname), "Doa")
-
-        firstname = "Tri"
-        lastname = ""
-        self.assertEqual(utils.get_trigram(firstname, lastname), "Tri")
-
-        firstname = ""
-        lastname = ""
-        self.assertEqual(utils.get_trigram(firstname, lastname), "")
diff --git a/pos_receipt_replace_user_by_trigram/utils.py b/pos_receipt_replace_user_by_trigram/utils.py
deleted file mode 100644
index c623f137b6..0000000000
--- a/pos_receipt_replace_user_by_trigram/utils.py
+++ /dev/null
@@ -1,11 +0,0 @@
-def get_trigram(*args):
-    valid = [x.strip() for x in args if x and x.strip()]
-    if valid:
-        if len(valid) > 1:
-            trigram = valid[0][:1] + valid[1][:2]
-        else:
-            trigram = valid[0][:3]
-    else:
-        trigram = ""
-
-    return trigram