diff --git a/addons/point_of_sale/point_of_sale.py b/addons/point_of_sale/point_of_sale.py
index 44139f7a499..2d6f0b7e005 100644
--- a/addons/point_of_sale/point_of_sale.py
+++ b/addons/point_of_sale/point_of_sale.py
@@ -523,6 +523,24 @@ class pos_order(osv.osv):
             wf_service.trg_validate(uid, 'pos.order', order_id, 'paid', cr)
         return order_ids
 
+    def write(self, cr, uid, ids, vals, context=None):
+        res = super(pos_order, self).write(cr, uid, ids, vals, context=context)
+        #If you change the partner of the PoS order, change also the partner of the associated bank statement lines
+        partner_obj = self.pool.get('res.partner')
+        bsl_obj = self.pool.get("account.bank.statement.line")
+        if 'partner_id' in vals:
+            for posorder in self.browse(cr, uid, ids, context=context):
+                if posorder.invoice_id:
+                    raise osv.except_osv( _('Error!'), _("You cannot change the partner of a POS order for which an invoice has already been issued."))
+                if vals['partner_id']:
+                    p_id = partner_obj.browse(cr, uid, vals['partner_id'], context=context)
+                    part_id = partner_obj._find_accounting_partner(p_id).id
+                else:
+                    part_id = False
+                bsl_ids = [x.id for x in posorder.statement_ids]
+                bsl_obj.write(cr, uid, bsl_ids, {'partner_id': part_id}, context=context)
+        return res
+
     def unlink(self, cr, uid, ids, context=None):
         for rec in self.browse(cr, uid, ids, context=context):
             if rec.state not in ('draft','cancel'):
@@ -951,9 +969,9 @@ class pos_order(osv.osv):
                 })
 
                 if data_type == 'product':
-                    key = ('product', values['product_id'],)
+                    key = ('product', values['partner_id'], values['product_id'])
                 elif data_type == 'tax':
-                    key = ('tax', values['tax_code_id'],)
+                    key = ('tax', values['partner_id'], values['tax_code_id'],)
                 elif data_type == 'counter_part':
                     key = ('counter_part', values['partner_id'], values['account_id'])
                 else:
@@ -1029,7 +1047,7 @@ class pos_order(osv.osv):
                     'debit': ((amount<0) and -amount) or 0.0,
                     'tax_code_id': tax_code_id,
                     'tax_amount': tax_amount,
-                    'partner_id': order.partner_id and order.partner_id.id or False
+                    'partner_id': order.partner_id and self.pool.get("res.partner")._find_accounting_partner(order.partner_id).id or False
                 })
 
                 # For each remaining tax with a code, whe create a move line
@@ -1047,6 +1065,7 @@ class pos_order(osv.osv):
                         'debit': 0.0,
                         'tax_code_id': tax_code_id,
                         'tax_amount': tax_amount,
+                        'partner_id': order.partner_id and self.pool.get("res.partner")._find_accounting_partner(order.partner_id).id or False
                     })
 
             # Create a move for each tax group
@@ -1063,6 +1082,7 @@ class pos_order(osv.osv):
                     'debit': ((tax_amount<0) and -tax_amount) or 0.0,
                     'tax_code_id': key[tax_code_pos],
                     'tax_amount': tax_amount,
+                    'partner_id': order.partner_id and self.pool.get("res.partner")._find_accounting_partner(order.partner_id).id or False
                 })
 
             # counterpart
@@ -1071,14 +1091,17 @@ class pos_order(osv.osv):
                 'account_id': order_account,
                 'credit': ((order.amount_total < 0) and -order.amount_total) or 0.0,
                 'debit': ((order.amount_total > 0) and order.amount_total) or 0.0,
-                'partner_id': order.partner_id and order.partner_id.id or False
+                'partner_id': order.partner_id and self.pool.get("res.partner")._find_accounting_partner(order.partner_id).id or False
             })
 
             order.write({'state':'done', 'account_move': move_id})
 
+        all_lines = []
         for group_key, group_data in grouped_data.iteritems():
             for value in group_data:
-                account_move_line_obj.create(cr, uid, value, context=context)
+                all_lines.append((0, 0, value),)
+        if move_id: #In case no order was changed
+            self.pool.get("account.move").write(cr, uid, [move_id], {'line_id':all_lines}, context=context)
 
         return True