diff --git a/l10n_br_sale/models/sale_order.py b/l10n_br_sale/models/sale_order.py
index 1006f43634dc..345e4cada79b 100644
--- a/l10n_br_sale/models/sale_order.py
+++ b/l10n_br_sale/models/sale_order.py
@@ -15,7 +15,8 @@ class SaleOrder(models.Model):
 
     @api.model
     def _default_fiscal_operation(self):
-        return self.env.company.sale_fiscal_operation_id
+        if self.env.company.country_id.code == "BR":
+            return self.env.company.sale_fiscal_operation_id
 
     @api.model
     def _default_copy_note(self):
@@ -100,8 +101,10 @@ def _get_amount_lines(self):
     )
     def _compute_amounts(self):
         """Compute the total amounts of the SO."""
-        for order in self:
+        result = super()._compute_amounts()
+        for order in self.filtered(lambda ln: ln.fiscal_operation_id):
             order._compute_fiscal_amount()
+        return result
 
     # TODO v16 override _compute_tax_totals ?
 
diff --git a/l10n_br_sale/models/sale_order_line.py b/l10n_br_sale/models/sale_order_line.py
index e7e0ae088922..e1314085ef1a 100644
--- a/l10n_br_sale/models/sale_order_line.py
+++ b/l10n_br_sale/models/sale_order_line.py
@@ -11,7 +11,8 @@ class SaleOrderLine(models.Model):
 
     @api.model
     def _default_fiscal_operation(self):
-        return self.env.company.sale_fiscal_operation_id
+        if self.order_id.fiscal_operation_id:
+            return self.env.company.sale_fiscal_operation_id
 
     @api.model
     def _fiscal_operation_domain(self):
@@ -180,7 +181,7 @@ def _get_protected_fields(self):
     def _compute_amount(self):
         """Compute the amounts of the SO line."""
         result = super()._compute_amount()
-        for line in self:
+        for line in self.filtered(lambda ln: ln.fiscal_operation_id):
             # Update taxes fields
             line._update_fiscal_taxes()
             # Call mixin compute method