diff --git a/models/__init__.py b/models/__init__.py
index ab87c94..26e4cbc 100644
--- a/models/__init__.py
+++ b/models/__init__.py
@@ -1,3 +1,4 @@
 from . import hr_employee
 from . import pos_config
+from . import pos_session
 from . import res_users
diff --git a/models/__pycache__/__init__.cpython-312.pyc b/models/__pycache__/__init__.cpython-312.pyc
index e5fbc03..459921e 100644
Binary files a/models/__pycache__/__init__.cpython-312.pyc and b/models/__pycache__/__init__.cpython-312.pyc differ
diff --git a/models/__pycache__/hr_employee.cpython-312.pyc b/models/__pycache__/hr_employee.cpython-312.pyc
index dbabc22..4c07b77 100644
Binary files a/models/__pycache__/hr_employee.cpython-312.pyc and b/models/__pycache__/hr_employee.cpython-312.pyc differ
diff --git a/models/hr_employee.py b/models/hr_employee.py
index 01d63c0..252478d 100644
--- a/models/hr_employee.py
+++ b/models/hr_employee.py
@@ -1,3 +1,4 @@
+import hashlib
 from odoo import models, fields, api, _
 
 class HrEmployee(models.Model):
@@ -91,7 +92,40 @@ class HrEmployee(models.Model):
         return super()._search(domain, offset=offset, limit=limit, order=order, **kwargs)
 
 
+    @api.model
+    def _load_pos_data_read(self, records, config):
+        """Override to read employee data (including work_contact_id / res.partner)
+        with sudo() so cashier users whose user.company_ids doesn't include the
+        employee partner's company_id don't get a read access error on session open.
+        The employee records are already filtered by _load_pos_data_domain before
+        arriving here, so sudo() is safe — we're only relaxing the partner rule.
+        """
+        fields = self._load_pos_data_fields(config)
+        # Read with sudo to bypass res.partner multi-company rule for work_contact_id
+        read_records = records.sudo().read(fields, load=False)
+        manager_ids = records.filtered(
+            lambda emp: config.group_pos_manager_id.id in emp.user_id.all_group_ids.ids
+        ).ids
 
+        employees_barcode_pin = records.get_barcodes_and_pin_hashed()
+        bp_per_employee_id = {bp_e['id']: bp_e for bp_e in employees_barcode_pin}
+
+        for employee in read_records:
+            if employee['id'] in manager_ids:
+                role = 'manager'
+                employee['_user_role'] = 'admin'
+            elif employee['id'] in config.advanced_employee_ids.ids:
+                role = 'manager'
+            elif employee['id'] in config.minimal_employee_ids.ids:
+                role = 'minimal'
+            else:
+                role = 'cashier'
+
+            employee['_role'] = role
+            employee['_barcode'] = bp_per_employee_id[employee['id']]['barcode']
+            employee['_pin'] = bp_per_employee_id[employee['id']]['pin']
+
+        return read_records
 
 
 class HrEmployeePublic(models.Model):
diff --git a/models/pos_session.py b/models/pos_session.py
new file mode 100644
index 0000000..24287c8
--- /dev/null
+++ b/models/pos_session.py
@@ -0,0 +1,22 @@
+from odoo import models
+
+
+class PosSession(models.Model):
+    _inherit = 'pos.session'
+
+    def _get_message_author(self):
+        """Override to read employee partner with sudo() to avoid res.partner
+        access errors when the cashier's allowed companies don't include the
+        company_id set on work_contact_id (caused by hr_multi_company_employee
+        assigning employees to branch companies).
+        """
+        if not self.employee_id:
+            return None
+
+        # Use sudo() to bypass multi-company partner rule when reading
+        # the employee's work_contact_id or user partner for message posting.
+        employee = self.employee_id.sudo()
+        if related_partners := employee._get_related_partners():
+            return related_partners[0]
+
+        return self.sudo().user_id.partner_id
diff --git a/security/hr_security.xml b/security/hr_security.xml
index d2bf101..6b6e66f 100644
--- a/security/hr_security.xml
+++ b/security/hr_security.xml
@@ -16,7 +16,11 @@
         </record>
 
         <record id="base.res_partner_rule" model="ir.rule">
-            <field name="domain_force">['|', '|', ('partner_share', '=', False), ('company_id', 'parent_of', company_ids), ('company_id', '=', False)]</field>
+            <!-- Override: allow access if company_id is in ANY of the user's allowed companies
+                 (user.company_ids), not only the currently active session companies (company_ids).
+                 This fixes the "read access to res.partner" error when viewing employees whose
+                 partner belongs to a non-active but permitted company. -->
+            <field name="domain_force">['|', '|', '|', ('partner_share', '=', False), ('company_id', 'parent_of', company_ids), ('company_id', 'in', user.company_ids.ids), ('company_id', '=', False)]</field>
         </record>
 
         <record id="base.res_company_rule_employee" model="ir.rule">