diff --git a/l10n_br_fiscal/models/operation_line.py b/l10n_br_fiscal/models/operation_line.py
index a94c8a459208..47a5b20a5620 100644
--- a/l10n_br_fiscal/models/operation_line.py
+++ b/l10n_br_fiscal/models/operation_line.py
@@ -117,6 +117,19 @@ class OperationLine(models.Model):
         string="Tax Definition",
     )
 
+    # Behavior for additional values and costs
+    additional_values_definition = fields.Selection(
+        selection=[
+            ("tax", "Defined In Tax (Default)"),
+            ("add", "Include"),
+            ("do_not_add", "Do not Include"),
+        ],
+        default="tax",
+        required=True,
+        string="Include other values in tax base",
+        help="If left unset, value from tax group will be used",
+    )
+
     comment_ids = fields.Many2many(
         comodel_name="l10n_br_fiscal.comment",
         relation="l10n_br_fiscal_operation_line_comment_rel",
diff --git a/l10n_br_fiscal/models/tax.py b/l10n_br_fiscal/models/tax.py
index 1a583402aa80..d156ae0b8a05 100644
--- a/l10n_br_fiscal/models/tax.py
+++ b/l10n_br_fiscal/models/tax.py
@@ -193,11 +193,23 @@ def _compute_tax_base(self, tax, tax_dict, **kwargs):
         insurance_value = kwargs.get("insurance_value", 0.00)
         freight_value = kwargs.get("freight_value", 0.00)
         other_value = kwargs.get("other_value", 0.00)
+        operation_line = kwargs.get("operation_line", False)
 
+        # Initialize additional value to be added to the base
+        add_value_to_base = 0
+
+        # Check if the tax group allows additional values to be included in the base
         if tax.tax_group_id.base_with_additional_values:
-            tax_dict["add_to_base"] += sum(
-                [freight_value, insurance_value, other_value]
-            )
+            add_value_to_base = sum([freight_value, insurance_value, other_value])
+
+        # If oper. line is set, adjust the additional values based on its definition
+        if operation_line:
+            if operation_line.additional_values_definition == "do_not_add":
+                add_value_to_base = 0
+            elif operation_line.additional_values_definition == "add":
+                add_value_to_base = sum([freight_value, insurance_value, other_value])
+
+        tax_dict["add_to_base"] += add_value_to_base
         tax_dict["remove_from_base"] += sum([discount_value])
 
         base = 0.00
diff --git a/l10n_br_fiscal/views/operation_line_view.xml b/l10n_br_fiscal/views/operation_line_view.xml
index 3a2120a3d11f..1f44c189c10f 100644
--- a/l10n_br_fiscal/views/operation_line_view.xml
+++ b/l10n_br_fiscal/views/operation_line_view.xml
@@ -81,6 +81,9 @@
                                 nolabel="1"
                                 context="{'tree_view_ref': 'l10n_br_fiscal.tax_definition_tree','form_view_ref': 'l10n_br_fiscal.tax_definition_form', 'default_fiscal_operation_line_id': id}"
                             />
+                            <group>
+                                <field name="additional_values_definition" />
+                            </group>
                       </page>
                       <page name="extra_info" string="Extra Info">
                         <group>