From e559fafa83359d5d2e2240ffd4c50f35368af2c4 Mon Sep 17 00:00:00 2001
From: Sagar Vora <16315650+sagarvora@users.noreply.github.com>
Date: Fri, 17 Oct 2025 16:12:30 +0530
Subject: [PATCH] fix: validate that discount amount cannot exceed total before
 discount

(cherry picked from commit f4f79d99e45a4e1f785d26713bf9f00045e9571f)

# Conflicts:
#	erpnext/controllers/taxes_and_totals.py
---
 erpnext/controllers/taxes_and_totals.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/erpnext/controllers/taxes_and_totals.py b/erpnext/controllers/taxes_and_totals.py
index 5543129d323..0048ec9acab 100644
--- a/erpnext/controllers/taxes_and_totals.py
+++ b/erpnext/controllers/taxes_and_totals.py
@@ -7,8 +7,12 @@ import json
 import frappe
 from frappe import _, scrub
 from frappe.model.document import Document
+<<<<<<< HEAD
 from frappe.utils import cint, flt, round_based_on_smallest_currency_fraction
 from frappe.utils.deprecations import deprecated
+=======
+from frappe.utils import cint, flt, fmt_money, round_based_on_smallest_currency_fraction
+>>>>>>> f4f79d99e4 (fix: validate that discount amount cannot exceed total before discount)
 
 import erpnext
 from erpnext.accounts.doctype.journal_entry.journal_entry import get_exchange_rate
@@ -682,6 +686,22 @@ class calculate_taxes_and_totals:
 				self.doc.precision("discount_amount"),
 			)
 
+		discount_amount = self.doc.discount_amount or 0
+		grand_total = self.doc.grand_total
+
+		# validate that discount amount cannot exceed the total before discount
+		if grand_total * (discount_amount - grand_total) > 0:
+			frappe.throw(
+				_(
+					"Additional Discount Amount ({discount_amount}) cannot exceed "
+					"the total before such discount ({total_before_discount})"
+				).format(
+					discount_amount=self.doc.get_formatted("discount_amount"),
+					total_before_discount=self.doc.get_formatted("grand_total"),
+				),
+				title=_("Invalid Discount Amount"),
+			)
+
 	def apply_discount_amount(self):
 		if self.doc.discount_amount:
 			if not self.doc.apply_discount_on: