diff --git a/addons/crm_livechat/models/mail_channel.py b/addons/crm_livechat/models/mail_channel.py
index f608bd1a0dd..b7650342d5a 100644
--- a/addons/crm_livechat/models/mail_channel.py
+++ b/addons/crm_livechat/models/mail_channel.py
@@ -26,16 +26,32 @@ class MailChannel(models.Model):
         self._send_transient_message(partner, msg)
 
     def _convert_visitor_to_lead(self, partner, channel_partners, key):
+        """ Create a lead from channel /lead command
+        :param partner: internal user partner (operator) that created the lead;
+        :param channel_partners: channel members;
+        :param key: operator input in chat ('/lead Lead about Product')
+        """
         description = ''.join(
             '%s: %s\n' % (message.author_id.name or self.anonymous_name, message.body)
             for message in self.channel_message_ids.sorted('id')
         )
+        # if public user is part of the chat: consider lead to be linked to an
+        # anonymous user whatever the participants. Otherwise keep only share
+        # partners (no user or portal user) to link to the lead.
+        customers = self.env['res.partner']
+        for customer in channel_partners.partner_id.filtered('partner_share'):
+            if customer.user_ids and all(user._is_public() for user in customer.user_ids):
+                customers = self.env['res.partner']
+                break
+            else:
+                customers |= customer
+
         utm_source = self.env.ref('crm_livechat.utm_source_livechat', raise_if_not_found=False)
         return self.env['crm.lead'].create({
             'name': html2plaintext(key[5:]),
-            'partner_id': channel_partners.partner_id.id,
-            'user_id': None,
-            'team_id': None,
+            'partner_id': customers[0].id if customers else False,
+            'user_id': False,
+            'team_id': False,
             'description': html2plaintext(description),
             'referred': partner.name,
             'source_id': utm_source and utm_source.id,
diff --git a/addons/crm_livechat/tests/__init__.py b/addons/crm_livechat/tests/__init__.py
new file mode 100644
index 00000000000..3721104aa97
--- /dev/null
+++ b/addons/crm_livechat/tests/__init__.py
@@ -0,0 +1,4 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from . import test_crm_lead
diff --git a/addons/crm_livechat/tests/test_crm_lead.py b/addons/crm_livechat/tests/test_crm_lead.py
new file mode 100644
index 00000000000..c3d6364e385
--- /dev/null
+++ b/addons/crm_livechat/tests/test_crm_lead.py
@@ -0,0 +1,77 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from odoo.addons.crm.tests.common import TestCrmCommon
+from odoo.addons.mail.tests.common import mail_new_test_user
+from odoo.tests.common import users
+
+
+class TestLivechatLead(TestCrmCommon):
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestLivechatLead, cls).setUpClass()
+
+        cls.user_anonymous = mail_new_test_user(
+            cls.env, login='user_anonymous',
+            name='Anonymous Website', email=False,
+            company_id=cls.company_main.id,
+            notification_type='inbox',
+            groups='base.group_public',
+        )
+        cls.user_portal = mail_new_test_user(
+            cls.env, login='user_portal',
+            name='Paulette Portal', email='user_portal@test.example.com',
+            company_id=cls.company_main.id,
+            notification_type='inbox',
+            groups='base.group_portal',
+        )
+
+    @users('user_sales_leads')
+    def test_crm_lead_creation_guest(self):
+        """ Test customer set on lead: not if public, guest if not public """
+        # public: should not be set as customer
+        channel = self.env['mail.channel'].create({
+            'name': 'Chat with Visitor',
+            'channel_partner_ids': [(4, self.user_anonymous.partner_id.id)]
+        })
+        lead = channel._convert_visitor_to_lead(self.env.user.partner_id, channel.channel_last_seen_partner_ids, '/lead TestLead command')
+
+        self.assertEqual(
+            channel.channel_last_seen_partner_ids.partner_id,
+            self.user_sales_leads.partner_id | self.user_anonymous.partner_id
+        )
+        self.assertEqual(lead.name, 'TestLead command')
+        self.assertEqual(lead.partner_id, self.env['res.partner'])
+
+        # public + someone else: no customer (as he was anonymous)
+        channel.write({
+            'channel_partner_ids': [(4, self.user_sales_manager.partner_id.id)]
+        })
+        lead = channel._convert_visitor_to_lead(self.env.user.partner_id, channel.channel_last_seen_partner_ids, '/lead TestLead command')
+        self.assertEqual(lead.partner_id, self.env['res.partner'])
+
+        # portal: should be set as customer
+        channel = self.env['mail.channel'].create({
+            'name': 'Chat with Visitor',
+            'channel_partner_ids': [(4, self.user_portal.partner_id.id)]
+        })
+        lead = channel._convert_visitor_to_lead(self.env.user.partner_id, channel.channel_last_seen_partner_ids, '/lead TestLead command')
+
+        self.assertEqual(
+            channel.channel_last_seen_partner_ids.partner_id,
+            self.user_sales_leads.partner_id | self.user_portal.partner_id
+        )
+        self.assertEqual(lead.partner_id, self.user_portal.partner_id)
+
+        # another operator invited: internal user should not be customer if portal is present
+        channel.write({
+            'channel_partner_ids': [(4, self.user_sales_manager.partner_id.id)]
+        })
+        lead = channel._convert_visitor_to_lead(self.env.user.partner_id, channel.channel_last_seen_partner_ids, '/lead TestLead command')
+
+        self.assertEqual(
+            channel.channel_last_seen_partner_ids.partner_id,
+            self.user_sales_leads.partner_id | self.user_portal.partner_id | self.user_sales_manager.partner_id
+        )
+        self.assertEqual(lead.partner_id, self.user_portal.partner_id)