diff --git a/odoo/addons/base/models/res_partner.py b/odoo/addons/base/models/res_partner.py
index 728bd040f1b..cb5d5f6b174 100644
--- a/odoo/addons/base/models/res_partner.py
+++ b/odoo/addons/base/models/res_partner.py
@@ -137,10 +137,15 @@ class Partner(models.Model):
 
     @api.model
     def default_get(self, default_fields):
-        """Add the company of the parent as default if we are creating a child partner."""
+        """Add the company of the parent as default if we are creating a child partner.
+        Also take the parent lang by default if any, otherwise, fallback to default DB lang."""
         values = super().default_get(default_fields)
+        parent = self.env["res.partner"]
         if 'parent_id' in default_fields and values.get('parent_id'):
-            values['company_id'] = self.browse(values.get('parent_id')).company_id.id
+            parent = self.browse(values.get('parent_id'))
+            values['company_id'] = parent.company_id.id
+        if 'lang' in default_fields:
+            values['lang'] = values.get('lang') or parent.lang or self.env.lang
         return values
 
     name = fields.Char(index=True)
@@ -151,7 +156,7 @@ class Partner(models.Model):
     parent_name = fields.Char(related='parent_id.name', readonly=True, string='Parent name')
     child_ids = fields.One2many('res.partner', 'parent_id', string='Contact', domain=[('active', '=', True)])  # force "active_test" domain to bypass _search() override
     ref = fields.Char(string='Reference', index=True)
-    lang = fields.Selection(_lang_get, string='Language', default=lambda self: self.env.lang,
+    lang = fields.Selection(_lang_get, string='Language',
                             help="All the emails and documents sent to this contact will be translated in this language.")
     active_lang_count = fields.Integer(compute='_compute_active_lang_count')
     tz = fields.Selection(_tz_get, string='Timezone', default=lambda self: self._context.get('tz'),
diff --git a/odoo/addons/base/views/res_partner_views.xml b/odoo/addons/base/views/res_partner_views.xml
index 1c346cbc60d..94ffaa2731d 100644
--- a/odoo/addons/base/views/res_partner_views.xml
+++ b/odoo/addons/base/views/res_partner_views.xml
@@ -222,7 +222,7 @@
 
                     <notebook colspan="4">
                         <page string="Contacts &amp; Addresses" name="contact_addresses" autofocus="autofocus">
-                            <field name="child_ids" mode="kanban" context="{'default_parent_id': active_id, 'default_street': street, 'default_street2': street2, 'default_city': city, 'default_state_id': state_id, 'default_zip': zip, 'default_country_id': country_id, 'default_lang': lang, 'default_user_id': user_id, 'default_type': 'other'}">
+                            <field name="child_ids" mode="kanban" context="{'default_parent_id': active_id, 'default_street': street, 'default_street2': street2, 'default_city': city, 'default_state_id': state_id, 'default_zip': zip, 'default_country_id': country_id, 'default_lang': None, 'default_user_id': user_id, 'default_type': 'other'}">
                                 <kanban>
                                     <field name="id"/>
                                     <field name="color"/>