diff --git a/account_supplier_invoice_check_duplicates/README.rst b/account_supplier_invoice_check_duplicates/README.rst
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+.. image:: https://img.shields.io/badge/license-AGPL--3-blue.png
+   :target: https://www.gnu.org/licenses/agpl
+   :alt: License: AGPL-3
+
+====================================
+Supplier Invoices - Check duplicates
+====================================
+
+This module adds logic to prevent entering two times the same supplier invoice.
+
+By default a duplicate is detected when there is already an open or paid invoice
+with 
+
+- same supplier
+- same supplier invoice number
+
+In case no supplier invoice number has been encoded extra checks are added to detect duplicates :
+
+- same date
+- same amount
+
+This logic can be customized via the _get_dup_domain method.
+
+The duplicate checking can be bypassed via the 'Force Encoding' flag.
+
+Known issues / Roadmap
+======================
+
+- Align this module with the OCA 'account_invoice_supplier_ref_unique' module.
diff --git a/account_supplier_invoice_check_duplicates/__init__.py b/account_supplier_invoice_check_duplicates/__init__.py
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+++ b/account_supplier_invoice_check_duplicates/__init__.py
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+from . import models
diff --git a/account_supplier_invoice_check_duplicates/__manifest__.py b/account_supplier_invoice_check_duplicates/__manifest__.py
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+++ b/account_supplier_invoice_check_duplicates/__manifest__.py
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+# Copyright 2009-2019 Noviat.
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+{
+    'name': 'Supplier Invoice - Check Duplicates',
+    'version': '11.0.1.0.0',
+    'category': 'Accounting & Finance',
+    'website': 'https://www.noviat.com',
+    'author': 'Noviat',
+    'license': 'AGPL-3',
+    'complexity': 'normal',
+    'summary': 'Supplier Invoice - Check Duplicates',
+    'data': [
+        'views/account_invoice_views.xml',
+    ],
+    'depends': [
+        'account_supplier_invoice_number',
+    ],
+    'excludes': [
+        'account_invoice_supplier_ref_unique',
+    ],
+    'installable': True,
+}
diff --git a/account_supplier_invoice_check_duplicates/models/__init__.py b/account_supplier_invoice_check_duplicates/models/__init__.py
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+++ b/account_supplier_invoice_check_duplicates/models/__init__.py
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+from . import account_invoice
diff --git a/account_supplier_invoice_check_duplicates/models/account_invoice.py b/account_supplier_invoice_check_duplicates/models/account_invoice.py
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+++ b/account_supplier_invoice_check_duplicates/models/account_invoice.py
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+# Copyright 2009-2019 Noviat.
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+from odoo import fields, models, _
+from odoo.exceptions import UserError
+
+
+class AccountInvoice(models.Model):
+    _inherit = 'account.invoice'
+
+    force_encoding = fields.Boolean(
+        string='Force Encoding',
+        readonly=True, states={'draft': [('readonly', False)]},
+        help="Accept the encoding of this invoice although "
+             "it looks like a duplicate.")
+
+    def _check_duplicate_supplier_reference(self):
+        """
+        Replace the standard addons _check_duplicate_supplier_reference
+        since this one is too restrictive (blocking) for certain use cases.
+        """
+        for invoice in self:
+            if invoice.type in ('in_invoice', 'in_refund') \
+                    and not invoice.force_encoding:
+                invoice._check_si_duplicate()
+
+    def _get_dup_domain(self):
+        """
+        Override this method to customize customer specific
+        duplicate check query.
+        """
+        return [
+            ('type', '=', self.type),
+            ('commercial_partner_id', '=', self.commercial_partner_id.id),
+            ('state', 'in', ['open', 'paid']),
+            ('company_id', '=', self.company_id.id),
+            ('id', '!=', self.id)]
+
+    def _get_dup_domain_extra(self):
+        """
+        Extra search term to detect duplicates in case no
+        supplier_invoice_number has been specified.
+        """
+        return [('date_invoice', '=', self.date_invoice),
+                ('amount_total', '=', self.amount_total)]
+
+    def _get_dup(self):
+        """
+        Override this method to customize customer specific
+        duplicate check logic
+        """
+        # find duplicates by date, amount
+        domain = self._get_dup_domain()
+        # add supplier invoice number
+        if self.supplier_invoice_number:
+            dom_dups = domain + [
+                ('supplier_invoice_number', 'ilike',
+                 self.supplier_invoice_number)]
+        else:
+            dom_dups = domain + self._get_dup_domain_extra()
+        return self.search(dom_dups)
+
+    def _check_si_duplicate(self):
+        dups = self._get_dup()
+        if dups:
+            raise UserError(_(
+                "This Supplier Invoice has already been encoded !"
+                "\nDuplicate Invoice: %s")
+                % ', '.join([x.number for x in dups]))
diff --git a/account_supplier_invoice_check_duplicates/static/description/icon.png b/account_supplier_invoice_check_duplicates/static/description/icon.png
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diff --git a/account_supplier_invoice_check_duplicates/views/account_invoice_views.xml b/account_supplier_invoice_check_duplicates/views/account_invoice_views.xml
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+++ b/account_supplier_invoice_check_duplicates/views/account_invoice_views.xml
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+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+
+  <record id="invoice_supplier_form" model="ir.ui.view">
+    <field name="name">account.invoice.supplier.form.inherit</field>
+    <field name="model">account.invoice</field>
+    <field name="inherit_id" ref="account.invoice_supplier_form"/>
+    <field name="arch" type="xml">
+      <field name="date_due" position="after">
+        <field name="force_encoding"/>
+      </field>
+    </field>
+  </record>
+
+</odoo>