diff --git a/addons/point_of_sale/point_of_sale.py b/addons/point_of_sale/point_of_sale.py
index 0d4f0275401..304f7d71061 100644
--- a/addons/point_of_sale/point_of_sale.py
+++ b/addons/point_of_sale/point_of_sale.py
@@ -1108,11 +1108,16 @@ class pos_order(osv.osv):
                     if not grouped_data[key]:
                         grouped_data[key].append(values)
                     else:
-                        current_value = grouped_data[key][0]
-                        current_value['quantity'] = current_value.get('quantity', 0.0) +  values.get('quantity', 0.0)
-                        current_value['credit'] = current_value.get('credit', 0.0) + values.get('credit', 0.0)
-                        current_value['debit'] = current_value.get('debit', 0.0) + values.get('debit', 0.0)
-                        current_value['tax_amount'] = current_value.get('tax_amount', 0.0) + values.get('tax_amount', 0.0)
+                        for line in grouped_data[key]:
+                            if line.get('tax_code_id') == values.get('tax_code_id'):
+                                current_value = line
+                                current_value['quantity'] = current_value.get('quantity', 0.0) +  values.get('quantity', 0.0)
+                                current_value['credit'] = current_value.get('credit', 0.0) + values.get('credit', 0.0)
+                                current_value['debit'] = current_value.get('debit', 0.0) + values.get('debit', 0.0)
+                                current_value['tax_amount'] = current_value.get('tax_amount', 0.0) + values.get('tax_amount', 0.0)
+                                break
+                        else:
+                            grouped_data[key].append(values)
                 else:
                     grouped_data[key].append(values)