[NEW] account_sub_account: create add-on

account_sub_accounts/models/__init__.py

@@ -0,0 +1,2 @@
+from . import res_parter
+from . import account_move_line

account_sub_accounts/models/account_move_line.py

@@ -0,0 +1,15 @@
+from odoo import fields, models
+
+
+class AccountMoveLine(models.Model):
+    _inherit = "account.move.line"
+
+    sub_account_customer = fields.Char(
+        string="Custommer sub-account",
+        related="partner_id.sub_account_customer"
+    )
+
+    sub_account_supplier = fields.Char(
+        string="Supplier sub-account",
+        related="partner_id.sub_account_supplier"
+    )

account_sub_accounts/models/res_parter.py

@@ -0,0 +1,8 @@
+from odoo import fields, models
+
+
+class Partner(models.Model):
+    _inherit = "res.partner"
+
+    sub_account_customer = fields.Char(string="Custommer sub-account")
+    sub_account_supplier = fields.Char(string="Supplier sub-account")