diff --git a/series b/series
index 2fcc2b3..dd524e9 100644
--- a/series
+++ b/series
@@ -6,6 +6,7 @@ account_payment_view.diff # [account_payment]
 issue8852.diff # [country] Adapt import_zip script to use the right subdivision type per country
 
 issue3932.diff # [account] rule account move and account move line by company
+tax_update_unit_price.diff # [account] Add the update_unit_price control on parent tax
 account_asset.diff # [account_asset] check if exist asset_lines
 
 
diff --git a/tax_update_unit_price.diff b/tax_update_unit_price.diff
new file mode 100644
index 0000000..53438c2
--- /dev/null
+++ b/tax_update_unit_price.diff
@@ -0,0 +1,13 @@
+diff --git a/tax.py b/tax.py
+--- a/trytond/trytond/modules/account/tax.py	Thu Gen 20 10:25:13 2020 +0200
++++ b/trytond/trytond/modules/account/tax.py	Thu Gen 20 10:32:48 2020 +0200
+@@ -906,7 +906,8 @@ class Tax(sequence_ordered(), ModelSQL, ModelView, DeactivableMixin):
+                 if len(tax.childs):
+                     values.extend(
+                         cls._unit_compute(tax.childs, price_unit, date))
+-                if tax.update_unit_price:
++                if (tax.update_unit_price or
++                        tax.parent and tax.parent.update_unit_price):
+                     for value in values:
+                         unit_price_variation += value['amount']
+                 res.extend(values)