diff --git a/pos_require_customer/i18n/nl_NL.po b/pos_require_customer/i18n/nl_NL.po
index 48acb40c..c5b5ab1a 100644
--- a/pos_require_customer/i18n/nl_NL.po
+++ b/pos_require_customer/i18n/nl_NL.po
@@ -6,8 +6,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: Odoo Server 8.0\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2015-06-02 11:36+0100\n"
-"PO-Revision-Date: 2015-06-02 11:36+0100\n"
+"POT-Creation-Date: 2015-06-02 15:04+0100\n"
+"PO-Revision-Date: 2015-06-02 15:04+0100\n"
 "Last-Translator: <>\n"
 "Language-Team: \n"
 "Language: nl_NL\n"
@@ -29,6 +29,12 @@ msgstr "Een anoniem kassa order kan niet worden bevestigd"
 msgid "Customer"
 msgstr "Klant"
 
+#. module: pos_require_customer
+#: code:addons/pos_require_customer/pos.py:45
+#, python-format
+msgid "Customer is required for this order and is missing"
+msgstr "Klant is vereist voor deze order en ontbreekt"
+
 #. module: pos_require_customer
 #. openerp-web
 #: code:addons/pos_require_customer/static/src/js/pos_require_customer.js:17
@@ -40,6 +46,11 @@ msgstr ""
 "Selecteer een klant voor dit order. Dit kan gedaan worden door te klikken op "
 "de tab bestelling"
 
+#. module: pos_require_customer
+#: model:ir.model,name:pos_require_customer.model_pos_order
+msgid "Point of Sale"
+msgstr "Kassa"
+
 #. module: pos_require_customer
 #: field:pos.config,require_customer:0
 msgid "Require customer"
@@ -50,5 +61,12 @@ msgstr "Klant verplichten"
 msgid "Require customer for orders in this point of sale"
 msgstr "Klant verplichten voor kassa orders in deze kassa."
 
+#. module: pos_require_customer
+#: view:pos.order:pos_require_customer.view_pos_pos_form_inherit
+msgid ""
+"{'readonly': [('state','=','invoiced')], 'required': "
+"[('require_customer','=',True)]}"
+msgstr ""
+
 #~ msgid "Require customer for pos orders in the frontend"
 #~ msgstr "Klant verplichten voor kassa orders in deze kassa."
diff --git a/pos_require_customer/i18n/pos_require_customer.pot b/pos_require_customer/i18n/pos_require_customer.pot
index f71c9993..ef64f016 100644
--- a/pos_require_customer/i18n/pos_require_customer.pot
+++ b/pos_require_customer/i18n/pos_require_customer.pot
@@ -6,8 +6,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: Odoo Server 8.0\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2015-06-02 09:24+0000\n"
-"PO-Revision-Date: 2015-06-02 09:24+0000\n"
+"POT-Creation-Date: 2015-06-02 13:03+0000\n"
+"PO-Revision-Date: 2015-06-02 13:03+0000\n"
 "Last-Translator: <>\n"
 "Language-Team: \n"
 "MIME-Version: 1.0\n"
@@ -27,6 +27,12 @@ msgstr ""
 msgid "Customer"
 msgstr ""
 
+#. module: pos_require_customer
+#: code:addons/pos_require_customer/pos.py:45
+#, python-format
+msgid "Customer is required for this order and is missing"
+msgstr ""
+
 #. module: pos_require_customer
 #. openerp-web
 #: code:addons/pos_require_customer/static/src/js/pos_require_customer.js:17
@@ -34,6 +40,11 @@ msgstr ""
 msgid "Please select a client for this order. This can be done by clicking the order tab"
 msgstr ""
 
+#. module: pos_require_customer
+#: model:ir.model,name:pos_require_customer.model_pos_order
+msgid "Point of Sale"
+msgstr ""
+
 #. module: pos_require_customer
 #: field:pos.config,require_customer:0
 msgid "Require customer"
@@ -44,3 +55,8 @@ msgstr ""
 msgid "Require customer for orders in this point of sale"
 msgstr ""
 
+#. module: pos_require_customer
+#: view:pos.order:pos_require_customer.view_pos_pos_form_inherit
+msgid "{'readonly': [('state','=','invoiced')], 'required': [('require_customer','=',True)]}"
+msgstr ""
+
diff --git a/pos_require_customer/pos.py b/pos_require_customer/pos.py
index f8b31e6d..138ae4b7 100644
--- a/pos_require_customer/pos.py
+++ b/pos_require_customer/pos.py
@@ -18,7 +18,8 @@
 #
 ##############################################################################
 
-from openerp import fields, models
+from openerp import fields, models, exceptions, api
+from openerp.tools.translate import _
 
 
 class PosConfig(models.Model):
@@ -27,3 +28,18 @@ class PosConfig(models.Model):
     require_customer = fields.Boolean(
         string='Require customer',
         help='Require customer for orders in this point of sale')
+
+
+class PosOrder(models.Model):
+    _inherit = 'pos.order'
+
+    require_customer = fields.Boolean(
+        string='Require customer',
+        related='session_id.config_id.require_customer', readonly=True)
+
+    @api.one
+    @api.constrains('partner_id', 'require_customer')
+    def _check_partner(self):
+        if self.require_customer and not self.partner_id:
+            raise exceptions.ValidationError(
+                _('Customer is required for this order and is missing'))
diff --git a/pos_require_customer/pos_view.xml b/pos_require_customer/pos_view.xml
index 1f0cece6..a0d8307d 100644
--- a/pos_require_customer/pos_view.xml
+++ b/pos_require_customer/pos_view.xml
@@ -16,5 +16,19 @@
             </field>
         </record>
 
+        <record model="ir.ui.view" id="view_pos_pos_form_inherit">
+            <field name="name">pos.order</field>
+            <field name="model">pos.order</field>
+            <field name="inherit_id" ref="point_of_sale.view_pos_pos_form"/>
+            <field name="arch" type="xml">
+                <xpath expr="//sheet" position="inside">
+                    <field name="require_customer" invisible="1"/>
+                </xpath>
+                <xpath expr="//field[@name='partner_id']" position="attributes">
+                    <attribute name="attrs">{'readonly': [('state','=','invoiced')], 'required': [('require_customer','=',True)]}</attribute>
+                </xpath>
+            </field>
+        </record>
+
     </data>
 </openerp>