From 53b61e5ac663a661fdfa3406bf210e73695d5191 Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Wed, 19 Aug 2026 12:01:42 +0000
Subject: [PATCH] fix(stock): preserve item UOM conversion factor (backport
 #58299) (#58304)

Co-authored-by: Mihir Kandoi <kandoimihir@gmail.com>
---
 erpnext/stock/doctype/item/item.js      |  6 ++++++
 erpnext/stock/doctype/item/item.py      |  3 +++
 erpnext/stock/doctype/item/test_item.py | 23 ++++++++++++++++++-----
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/erpnext/stock/doctype/item/item.js b/erpnext/stock/doctype/item/item.js
index 909da62a492..67a7c3564dc 100644
--- a/erpnext/stock/doctype/item/item.js
+++ b/erpnext/stock/doctype/item/item.js
@@ -7,6 +7,12 @@ const SALES_DOCTYPES = ["Quotation", "Sales Order", "Delivery Note", "Sales Invo
 const PURCHASE_DOCTYPES = ["Purchase Order", "Purchase Receipt", "Purchase Invoice"];
 
 frappe.ui.form.on("Item", {
+	stock_uom(frm) {
+		// Each factor is relative to Stock UOM and becomes invalid when it changes.
+		frm.clear_table("uoms");
+		frm.refresh_field("uoms");
+	},
+
 	valuation_method(frm) {
 		if (!frm.is_new() && frm.doc.valuation_method === "Moving Average") {
 			let stock_exists = frm.doc.__onload && frm.doc.__onload.stock_exists ? 1 : 0;
diff --git a/erpnext/stock/doctype/item/item.py b/erpnext/stock/doctype/item/item.py
index a11c9b1c6dc..03197ca4114 100644
--- a/erpnext/stock/doctype/item/item.py
+++ b/erpnext/stock/doctype/item/item.py
@@ -1023,6 +1023,9 @@ class Item(Document):
 	def validate_uom_conversion_factor(self):
 		if self.uoms:
 			for d in self.uoms:
+				if d.conversion_factor:
+					continue
+
 				value = get_uom_conv_factor(d.uom, self.stock_uom)
 				if value:
 					d.conversion_factor = value
diff --git a/erpnext/stock/doctype/item/test_item.py b/erpnext/stock/doctype/item/test_item.py
index 221c45e3591..72c5b1465f3 100644
--- a/erpnext/stock/doctype/item/test_item.py
+++ b/erpnext/stock/doctype/item/test_item.py
@@ -749,15 +749,25 @@ class TestItem(ERPNextTestSuite):
 			"Test Item UOM", {"stock_uom": "Gram", "uoms": [dict(uom="Carat"), dict(uom="Kg")]}
 		)
 
-		for d in item_doc.uoms:
-			value = get_uom_conv_factor(d.uom, item_doc.stock_uom)
-			d.conversion_factor = value
-
 		self.assertEqual(item_doc.uoms[0].uom, "Carat")
 		self.assertEqual(item_doc.uoms[0].conversion_factor, 0.2)
 		self.assertEqual(item_doc.uoms[1].uom, "Kg")
 		self.assertEqual(item_doc.uoms[1].conversion_factor, 1000)
 
+	def test_item_uom_conversion_factor_overrides_global_factor(self):
+		custom_factor = 10.76
+		global_factor = get_uom_conv_factor("Square Meter", "Square Foot")
+		self.assertNotEqual(custom_factor, global_factor)
+
+		item = make_item(
+			properties={"stock_uom": "Square Foot"},
+			uoms=[{"uom": "Square Meter", "conversion_factor": custom_factor}],
+		)
+		item.reload()
+
+		conversion_factor = next(row.conversion_factor for row in item.uoms if row.uom == "Square Meter")
+		self.assertEqual(conversion_factor, custom_factor)
+
 	def test_uom_conv_intermediate(self):
 		factor = get_uom_conv_factor("Pound", "Gram")
 		self.assertAlmostEqual(factor, 453.592, 3)
@@ -930,7 +940,10 @@ class TestItem(ERPNextTestSuite):
 		item.reload()
 		item.stock_uom = "Nos"
 		item.save()
-		self.assertEqual(len(item.uoms), 1)
+		self.assertEqual(
+			[(row.uom, row.conversion_factor) for row in item.uoms],
+			[("Nos", 1)],
+		)
 
 	def test_validate_stock_item(self):
 		self.assertRaises(frappe.ValidationError, validate_is_stock_item, "_Test Non Stock Item")