diff --git a/addons/account/models/account_tax_report.py b/addons/account/models/account_tax_report.py
index 8825c004971..95c0c9a7b2b 100644
--- a/addons/account/models/account_tax_report.py
+++ b/addons/account/models/account_tax_report.py
@@ -54,11 +54,7 @@ class AccountTaxReport(models.Model):
         copied_report = super(AccountTaxReport, self).copy(default=copy_default) #This copies the report without its lines
 
         lines_map = {} # maps original lines to their copies (using ids)
-        lines_to_treat = list(self.line_ids.filtered(lambda x: not x.parent_id))
-        while lines_to_treat:
-            line = lines_to_treat.pop()
-            lines_to_treat += list(line.children_line_ids)
-
+        for line in self.get_lines_in_hierarchy():
             copy = line.copy({'parent_id': lines_map.get(line.parent_id.id, None), 'report_id': copied_report.id})
             lines_map[line.id] = copy.id
 
@@ -69,10 +65,10 @@ class AccountTaxReport(models.Model):
         ar all directly followed by their children.
         """
         self.ensure_one()
-        lines_to_treat = list(self.line_ids.filtered(lambda x: not x.parent_id).sorted(lambda x: x.sequence)) # Used as a stack, whose index 0 is the top
+        lines_to_treat = list(self.line_ids.filtered(lambda x: not x.parent_id)) # Used as a stack, whose index 0 is the top
         while lines_to_treat:
             to_yield = lines_to_treat[0]
-            lines_to_treat = list(to_yield.children_line_ids.sorted(lambda x: x.sequence)) + lines_to_treat[1:]
+            lines_to_treat = list(to_yield.children_line_ids) + lines_to_treat[1:]
             yield to_yield
 
     def get_checks_to_perform(self, amounts, carried_over):
@@ -95,7 +91,7 @@ class AccountTaxReport(models.Model):
 class AccountTaxReportLine(models.Model):
     _name = "account.tax.report.line"
     _description = 'Account Tax Report Line'
-    _order = 'sequence'
+    _order = 'sequence, id'
     _parent_store = True
 
     name = fields.Char(