diff --git a/addons/hr_timesheet/models/hr_timesheet.py b/addons/hr_timesheet/models/hr_timesheet.py
index 6eea1f57c41..96ba98a2431 100644
--- a/addons/hr_timesheet/models/hr_timesheet.py
+++ b/addons/hr_timesheet/models/hr_timesheet.py
@@ -63,6 +63,7 @@ class AccountAnalyticLine(models.Model):
     manager_id = fields.Many2one('hr.employee', "Manager", related='employee_id.parent_id', store=True)
     encoding_uom_id = fields.Many2one('uom.uom', compute='_compute_encoding_uom_id')
     partner_id = fields.Many2one(compute='_compute_partner_id', store=True, readonly=False)
+    readonly_timesheet = fields.Boolean(string="Readonly Timesheet", compute="_compute_readonly_timesheet")
 
     def name_get(self):
         result = super().name_get()
@@ -82,6 +83,16 @@ class AccountAnalyticLine(models.Model):
         timesheet_dict = {res['id']: _get_display_name(res['project_id'], res['task_id']) for res in timesheets_read}
         return list({**dict(result), **timesheet_dict}.items())
 
+    def _is_readonly(self):
+        self.ensure_one()
+        # is overridden in other timesheet related modules
+        return False
+
+    def _compute_readonly_timesheet(self):
+        readonly_timesheets = self.filtered(lambda timesheet: timesheet._is_readonly())
+        readonly_timesheets.readonly_timesheet = True
+        (self - readonly_timesheets).readonly_timesheet = False
+
     def _compute_encoding_uom_id(self):
         for analytic_line in self:
             analytic_line.encoding_uom_id = analytic_line.company_id.timesheet_encode_uom_id
diff --git a/addons/hr_timesheet/views/hr_timesheet_views.xml b/addons/hr_timesheet/views/hr_timesheet_views.xml
index 13080293ac8..379931a88ec 100644
--- a/addons/hr_timesheet/views/hr_timesheet_views.xml
+++ b/addons/hr_timesheet/views/hr_timesheet_views.xml
@@ -5,13 +5,14 @@
             <field name="name">account.analytic.line.tree.hr_timesheet</field>
             <field name="model">account.analytic.line</field>
             <field name="arch" type="xml">
-                <tree editable="bottom" string="Timesheet Activities" sample="1">
-                    <field name="date"/>
-                    <field name="employee_id" invisible="1"/>
-                    <field name="project_id" required="1" options="{'no_create_edit': True, 'no_open': 1}"/>
-                    <field name="task_id" optional="show" options="{'no_create_edit': True, 'no_open': True}" widget="task_with_hours" context="{'default_project_id': project_id}"/>
-                    <field name="name" optional="show" required="0"/>
-                    <field name="unit_amount" optional="show" widget="timesheet_uom" sum="Total" decoration-danger="unit_amount &gt; 24 or unit_amount &lt; 0"/>
+                <tree editable="bottom" string="Timesheet Activities" sample="1" decoration-muted="readonly_timesheet == True">
+                    <field name="readonly_timesheet" invisible="1"/>
+                    <field name="date" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                    <field name="employee_id" invisible="1" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                    <field name="project_id" required="1" options="{'no_create_edit': True, 'no_open': 1}" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                    <field name="task_id" optional="show" options="{'no_create_edit': True, 'no_open': True}" widget="task_with_hours" context="{'default_project_id': project_id}" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                    <field name="name" optional="show" required="0" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                    <field name="unit_amount" optional="show" widget="timesheet_uom" sum="Total" decoration-danger="unit_amount &gt; 24 or unit_amount &lt; 0" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
                     <field name="company_id" invisible="1"/>
                     <field name="user_id" invisible="1"/>
                 </tree>
@@ -120,15 +121,18 @@
                     <sheet string="Analytic Entry">
                         <group>
                             <group>
-                                <field name="project_id" required="1"/>
-                                <field name="task_id" widget="task_with_hours" context="{'default_project_id': project_id}"/>
-                                <field name="name"/>
+                                <field name="readonly_timesheet" invisible="1"/>
+                                <field name="project_id" required="1" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                                <field name="task_id" widget="task_with_hours" context="{'default_project_id': project_id}"
+                                    attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                                <field name="name" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
                                 <field name="company_id" groups="base.group_multi_company" invisible="1"/>
                             </group>
                             <group>
-                                <field name="date"/>
+                                <field name="date" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
                                 <field name="amount" invisible="1"/>
-                                <field name="unit_amount" widget="timesheet_uom" decoration-danger="unit_amount &gt; 24"/>
+                                <field name="unit_amount" widget="timesheet_uom" decoration-danger="unit_amount &gt; 24"
+                                    attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
                                 <field name="currency_id" invisible="1"/>
                                 <field name="company_id" invisible="1"/>
                             </group>
@@ -146,7 +150,7 @@
             <field name="priority">10</field>
             <field name="arch" type="xml">
                 <xpath expr="//field[@name='date']" position="before">
-                    <field name="employee_id" required="1" context="{'active_test': True}"/>
+                    <field name="employee_id" required="1" context="{'active_test': True}" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
                     <field name="user_id" invisible="1"/>
                 </xpath>
             </field>
diff --git a/addons/hr_timesheet/views/project_task_views.xml b/addons/hr_timesheet/views/project_task_views.xml
index 39cf7ac4bcb..694e08a97b2 100644
--- a/addons/hr_timesheet/views/project_task_views.xml
+++ b/addons/hr_timesheet/views/project_task_views.xml
@@ -40,12 +40,15 @@
                             </div>
                         </group>
                     <field name="timesheet_ids" mode="tree,kanban" attrs="{'invisible': [('analytic_account_active', '=', False)]}" context="{'default_project_id': project_id, 'default_name':''}">
-                        <tree editable="bottom" string="Timesheet Activities" default_order="date">
-                            <field name="date"/>
+                        <tree editable="bottom" string="Timesheet Activities" default_order="date" decoration-muted="readonly_timesheet == True">
+                            <field name="readonly_timesheet" invisible="1"/>
+                            <field name="date" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
                             <field name="user_id" invisible="1"/>
-                            <field name="employee_id" required="1" widget="many2one_avatar_employee" context="{'active_test': True}"/>
-                            <field name="name" required="0"/>
-                            <field name="unit_amount" widget="timesheet_uom" decoration-danger="unit_amount &gt; 24 or unit_amount &lt; 0"/>
+                            <field name="employee_id" required="1" widget="many2one_avatar_employee"
+                                context="{'active_test': True}" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                            <field name="name" required="0" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                            <field name="unit_amount" widget="timesheet_uom" decoration-danger="unit_amount &gt; 24 or unit_amount &lt; 0"
+                                attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
                             <field name="project_id" invisible="1"/>
                             <field name="task_id" invisible="1"/>
                             <field name="company_id" invisible="1"/>
@@ -86,11 +89,14 @@
                         <form  string="Timesheet Activities">
                             <sheet>
                                  <group>
-                                    <field name="date"/>
-                                    <field name="user_id" invisible="1"/>
-                                    <field name="employee_id" required="1" widget="many2one_avatar_employee" context="{'active_test': True}"/>
-                                    <field name="name" required="0"/>
-                                    <field name="unit_amount" string="Duration" widget="float_time" decoration-danger="unit_amount &gt; 24"/>
+                                    <field name="readonly_timesheet" invisible="1"/>
+                                    <field name="date" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                                    <field name="user_id" invisible="1" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                                    <field name="employee_id" required="1" widget="many2one_avatar_employee" context="{'active_test': True}"
+                                        attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                                    <field name="name" required="0" attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
+                                    <field name="unit_amount" string="Duration" widget="float_time" decoration-danger="unit_amount &gt; 24"
+                                        attrs="{'readonly': [('readonly_timesheet', '=', True)]}"/>
                                     <field name="project_id" invisible="1"/>
                                     <field name="task_id" invisible="1"/>
                                     <field name="company_id" invisible="1"/>
diff --git a/addons/sale_timesheet/models/account.py b/addons/sale_timesheet/models/account.py
index c9d62e277f9..4b0cae00927 100644
--- a/addons/sale_timesheet/models/account.py
+++ b/addons/sale_timesheet/models/account.py
@@ -79,6 +79,9 @@ class AccountAnalyticLine(models.Model):
     def _compute_project_id(self):
         super(AccountAnalyticLine, self.filtered(lambda t: t._is_not_billed()))._compute_project_id()
 
+    def _is_readonly(self):
+        return super()._is_readonly() or not self._is_not_billed()
+
     def _is_not_billed(self):
         self.ensure_one()
         return not self.timesheet_invoice_id or self.timesheet_invoice_id.state == 'cancel'
diff --git a/addons/sale_timesheet/views/hr_timesheet_views.xml b/addons/sale_timesheet/views/hr_timesheet_views.xml
index 78c2f93836f..e900cf12e1f 100644
--- a/addons/sale_timesheet/views/hr_timesheet_views.xml
+++ b/addons/sale_timesheet/views/hr_timesheet_views.xml
@@ -45,7 +45,7 @@
                 <field name="commercial_partner_id" invisible="1" groups="sales_team.group_sale_salesman"/>
                 <field name="is_so_line_edited" invisible="1" groups="sales_team.group_sale_salesman"/>
                 <field name="allow_billable" invisible="1" groups="sales_team.group_sale_salesman"/>
-                <field name="so_line" widget="so_line_field" optional="hide" options="{'no_create': True}" context="{'create': False, 'edit': False, 'delete': False}" attrs="{'invisible': [('allow_billable', '=', False)]}" placeholder="Non-billable" groups="sales_team.group_sale_salesman"/>
+                <field name="so_line" widget="so_line_field" optional="show" options="{'no_create': True}" context="{'create': False, 'edit': False, 'delete': False}" attrs="{'invisible': [('allow_billable', '=', False)], 'readonly': [('readonly_timesheet', '=', True)]}" placeholder="Non-billable" groups="sales_team.group_sale_salesman"/>
             </xpath>
         </field>
     </record>
@@ -59,7 +59,7 @@
                 <field name="commercial_partner_id" invisible="1" groups="sales_team.group_sale_salesman"/>
                 <field name="is_so_line_edited" invisible="1" groups="sales_team.group_sale_salesman"/>
                 <field name="allow_billable" invisible="1" groups="sales_team.group_sale_salesman"/>
-                <field name="so_line" widget="so_line_field" options='{"no_create": True}' context="{'create': False, 'edit': False, 'delete': False, 'with_price_unit': True}" attrs="{'invisible': [('allow_billable', '=', False)]}" placeholder="Non-billable" groups="sales_team.group_sale_salesman"/>
+                <field name="so_line" widget="so_line_field" options='{"no_create": True}' context="{'create': False, 'edit': False, 'delete': False, 'with_price_unit': True}" attrs="{'invisible': [('allow_billable', '=', False)], 'readonly': [('readonly_timesheet', '=', True)]}" placeholder="Non-billable" groups="sales_team.group_sale_salesman"/>
             </xpath>
         </field>
     </record>
diff --git a/addons/sale_timesheet/views/project_task_views.xml b/addons/sale_timesheet/views/project_task_views.xml
index 05ad66e377d..682037544ba 100644
--- a/addons/sale_timesheet/views/project_task_views.xml
+++ b/addons/sale_timesheet/views/project_task_views.xml
@@ -126,10 +126,6 @@
             <field name="model">project.task</field>
             <field name="inherit_id" ref="project.view_task_form2"/>
             <field name="arch" type="xml">
-                <xpath expr="//field[@name='timesheet_ids']/tree" position="attributes">
-                    <!-- <field name="timesheet_ids"/> is already inside a block groups="hr_timesheet.group_hr_timesheet_user"  -->
-                    <attribute name="decoration-muted">timesheet_invoice_id != False</attribute>
-                </xpath>
                 <xpath expr="//field[@name='user_ids']" position="after">
                     <field name="is_project_map_empty" invisible="1" groups="hr_timesheet.group_hr_timesheet_user"/>
                     <field name="has_multi_sol" invisible="1" groups="hr_timesheet.group_hr_timesheet_user"/>
@@ -149,12 +145,12 @@
                     <!-- <field name="timesheet_ids"/> is already inside a block groups="hr_timesheet.group_hr_timesheet_user"  -->
                     <field name="timesheet_invoice_id" invisible="1"/>
                     <field name="so_line" groups="!sales_team.group_sale_salesman"
-                        attrs="{'column_invisible': [('parent.allow_billable', '=', False)]}"
+                        attrs="{'column_invisible': [('parent.allow_billable', '=', False)], 'readonly': [('readonly_timesheet', '=', True)]}"
                         context="{'with_remaining_hours': True, 'with_price_unit': True}" options="{'no_create': True, 'no_open': True}"
                         domain="[('is_service', '=', True), ('order_partner_id', 'child_of', parent.partner_id), ('is_expense', '=', False), ('state', 'in', ['sale', 'done'])]"
                         optional="hide"/>
                     <field name="so_line" groups="sales_team.group_sale_salesman"
-                        attrs="{'column_invisible': [('parent.allow_billable', '=', False)]}"
+                        attrs="{'column_invisible': [('parent.allow_billable', '=', False)], 'readonly': [('readonly_timesheet', '=', True)]}"
                         context="{'with_remaining_hours': True, 'with_price_unit': True}" options="{'no_create': True}"
                         domain="[('is_service', '=', True), ('order_partner_id', 'child_of', parent.partner_id), ('is_expense', '=', False), ('state', 'in', ['sale', 'done'])]"
                         optional="hide"/>