diff --git a/account_constraints/__init__.py b/account_constraints/__init__.py
new file mode 100644
index 000000000..ef69cef93
--- /dev/null
+++ b/account_constraints/__init__.py
@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+##############################################################################
+#
+#    Author Joel Grand-Guillaume. Copyright 2012 Camptocamp SA
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+import account_constraints
\ No newline at end of file
diff --git a/account_constraints/__openerp__.py b/account_constraints/__openerp__.py
new file mode 100644
index 000000000..222b3e365
--- /dev/null
+++ b/account_constraints/__openerp__.py
@@ -0,0 +1,56 @@
+# -*- coding: utf-8 -*-
+##############################################################################
+#
+#    Author Joel Grand-Guillaume. Copyright 2012 Camptocamp SA
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+{
+    'name' : 'Account Constraints',
+    'version' : '1.0',
+    'depends' : [
+                 'account',
+                 ],
+    'author' : 'Camptocamp',
+    'license': 'AGPL-3',
+    'category': 'Generic Modules/Accounting',
+    'description': """
+Account Constraints
+===================
+
+Add constraints in the accounting module of OpenERP to avoid bad usage
+by users that lead to corrupted datas. This is based on our experiences
+and legal state of the art in other software.
+
+Summary of constraints are:
+
+* Add a constraint on account move: you cannot pickup a date that is not
+  in the fiscal year of the concerned period
+
+* For manual entries when multicurrency:
+
+  a. Validation on the use of the 'Currency' and 'Currency Amount'
+     fields as it is possible to enter one without the other
+  b. Validation to prevent a Credit amount with a positive
+     'Currency Amount', or a Debit with a negative 'Currency Amount'
+
+* Add a check on entries that user cannot provide a secondary currency
+  if the same than the company one.
+
+    """,
+    'website': 'http://www.camptocamp.com',
+    'data': [],
+    'installable': True,
+}
diff --git a/account_constraints/account_constraints.py b/account_constraints/account_constraints.py
new file mode 100644
index 000000000..861005daa
--- /dev/null
+++ b/account_constraints/account_constraints.py
@@ -0,0 +1,84 @@
+# -*- coding: utf-8 -*-
+##############################################################################
+#
+#    Author Joel Grand-Guillaume. Copyright 2012 Camptocamp SA
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+
+from openerp.osv import fields, orm
+
+
+class AccountMove(orm.Model):
+    _inherit = "account.move"
+
+    def _check_fiscal_year(self, cr, uid, ids):
+        for move in self.browse(cr, uid, ids):
+            date_start = move.period_id.fiscalyear_id.date_start
+            date_stop = move.period_id.fiscalyear_id.date_stop
+            if not date_start <= move.date <= date_stop:
+                return False
+        return True
+
+    _constraints = [
+        (_check_fiscal_year,
+            'You cannot create entries with date not in the '
+            'fiscal year of the chosen period',
+            ['line_id']),
+    ]
+
+
+class AccountMoveLine(orm.Model):
+    _inherit = 'account.move.line'
+
+    def _check_currency_and_amount(self, cr, uid, ids, context=None):
+        for l in self.browse(cr, uid, ids, context=context):
+            if ((l.currency_id and not l.amount_currency) or
+                    (not l.currency_id and l.amount_currency)):
+                return False
+        return True
+
+    def _check_currency_amount(self, cr, uid, ids, context=None):
+        for l in self.browse(cr, uid, ids, context=context):
+            if l.amount_currency:
+                if ((l.amount_currency > 0.0 and l.credit > 0.0) or
+                        (l.amount_currency < 0.0 and l.debit > 0.0)):
+                    return False
+        return True
+
+    def _check_currency_company(self, cr, uid, ids, context=None):
+        for l in self.browse(cr, uid, ids, context=context):
+            if l.currency_id.id == l.company_id.currency_id.id:
+                return False
+        return True
+
+    _constraints = [
+            (_check_currency_and_amount,
+             "You cannot create journal items with a secondary currency "
+             "without recording both 'currency' and 'amount currency' field.",
+             ['currency_id','amount_currency']
+            ),
+            (_check_currency_amount,
+             "The amount expressed in the secondary currency must be positive "
+             "when journal item are debit and negatif when journal item are "
+             "credit.",
+              ['amount_currency']
+            ),
+            (_check_currency_company,
+             "You can't provide a secondary currency if "
+             "the same than the company one.",
+             ['currency_id']
+            ),
+        ]