diff --git a/erpnext/buying/doctype/purchase_order/test_purchase_order.py b/erpnext/buying/doctype/purchase_order/test_purchase_order.py
index 7c8ae6c..0cf3d24 100644
--- a/erpnext/buying/doctype/purchase_order/test_purchase_order.py
+++ b/erpnext/buying/doctype/purchase_order/test_purchase_order.py
@@ -203,9 +203,39 @@
 		frappe.set_user("Administrator")
 
 	def test_update_child_with_tax_template(self):
+		"""
+			Test Action: Create a PO with one item having its tax account head already in the PO.
+			Add the same item + new item with tax template via Update Items.
+			Expected result: First Item's tax row is updated. New tax row is added for second Item.
+		"""
+		if not frappe.db.exists("Item", "Test Item with Tax"):
+			make_item("Test Item with Tax", {
+				'is_stock_item': 1,
+			})
+
+		if not frappe.db.exists("Item Tax Template", {"title": 'Test Update Items Template'}):
+			frappe.get_doc({
+				'doctype': 'Item Tax Template',
+				'title': 'Test Update Items Template',
+				'company': '_Test Company',
+				'taxes': [
+					{
+						'tax_type': "_Test Account Service Tax - _TC",
+						'tax_rate': 10,
+					}
+				]
+			}).insert()
+
+		new_item_with_tax = frappe.get_doc("Item", "Test Item with Tax")
+
+		new_item_with_tax.append("taxes", {
+			"item_tax_template": "Test Update Items Template",
+			"valid_from": nowdate()
+		})
+		new_item_with_tax.save()
+
 		tax_template = "_Test Account Excise Duty @ 10"
 		item =  "_Test Item Home Desktop 100"
-
 		if not frappe.db.exists("Item Tax", {"parent":item, "item_tax_template":tax_template}):
 			item_doc = frappe.get_doc("Item", item)
 			item_doc.append("taxes", {
@@ -237,17 +267,25 @@
 
 		items = json.dumps([
 			{'item_code' : item, 'rate' : 500, 'qty' : 1, 'docname': po.items[0].name},
-			{'item_code' : item, 'rate' : 100, 'qty' : 1} # added item
+			{'item_code' : item, 'rate' : 100, 'qty' : 1}, # added item whose tax account head already exists in PO
+			{'item_code' : new_item_with_tax.name, 'rate' : 100, 'qty' : 1} # added item whose tax account head  is missing in PO
 		])
 		update_child_qty_rate('Purchase Order', items, po.name)
 
 		po.reload()
-		self.assertEqual(po.taxes[0].tax_amount, 60)
-		self.assertEqual(po.taxes[0].total, 660)
+		self.assertEqual(po.taxes[0].tax_amount, 70)
+		self.assertEqual(po.taxes[0].total, 770)
+		self.assertEqual(po.taxes[1].account_head, "_Test Account Service Tax - _TC")
+		self.assertEqual(po.taxes[1].tax_amount, 70)
+		self.assertEqual(po.taxes[1].total, 840)
 
+		# teardown
 		frappe.db.sql("""UPDATE `tabItem Tax` set valid_from = NULL
-				where parent = %(item)s and item_tax_template = %(tax)s""",
-					{"item": item, "tax": tax_template})
+			where parent = %(item)s and item_tax_template = %(tax)s""", {"item": item, "tax": tax_template})
+		po.cancel()
+		po.delete()
+		new_item_with_tax.delete()
+		frappe.get_doc("Item Tax Template", "Test Update Items Template").delete()
 
 	def test_update_child_uom_conv_factor_change(self):
 		po = create_purchase_order(item_code="_Test FG Item", is_subcontracted="Yes")
diff --git a/erpnext/controllers/accounts_controller.py b/erpnext/controllers/accounts_controller.py
index 1818cb6..fc32977 100644
--- a/erpnext/controllers/accounts_controller.py
+++ b/erpnext/controllers/accounts_controller.py
@@ -1168,6 +1168,31 @@
 	if child_item.get("item_tax_template"):
 		child_item.item_tax_rate = get_item_tax_map(parent_doc.get('company'), child_item.item_tax_template, as_json=True)
 
+def add_taxes_from_tax_template(child_item, parent_doc):
+	add_taxes_from_item_tax_template = frappe.db.get_single_value("Accounts Settings", "add_taxes_from_item_tax_template")
+
+	if child_item.get("item_tax_rate") and add_taxes_from_item_tax_template:
+		tax_map = json.loads(child_item.get("item_tax_rate"))
+		for tax_type in tax_map:
+			tax_rate = flt(tax_map[tax_type])
+			taxes = parent_doc.get('taxes') or []
+			# add new row for tax head only if missing
+			found = any(tax.account_head == tax_type for tax in taxes)
+			if not found:
+				tax_row = parent_doc.append("taxes", {})
+				tax_row.update({
+					"description" : str(tax_type).split(' - ')[0],
+					"charge_type" : "On Net Total",
+					"account_head" : tax_type,
+					"rate" : tax_rate
+				})
+				if parent_doc.doctype == "Purchase Order":
+					tax_row.update({
+						"category" : "Total",
+						"add_deduct_tax" : "Add"
+					})
+				tax_row.db_insert()
+
 def set_sales_order_defaults(parent_doctype, parent_doctype_name, child_docname, trans_item):
 	"""
 	Returns a Sales Order Item child item containing the default values
@@ -1183,6 +1208,7 @@
 	conversion_factor = flt(get_conversion_factor(item.item_code, child_item.uom).get("conversion_factor"))
 	child_item.conversion_factor = flt(trans_item.get('conversion_factor')) or conversion_factor
 	set_child_tax_template_and_map(item, child_item, p_doc)
+	add_taxes_from_tax_template(child_item, p_doc)
 	child_item.warehouse = get_item_warehouse(item, p_doc, overwrite_warehouse=True)
 	if not child_item.warehouse:
 		frappe.throw(_("Cannot find {} for item {}. Please set the same in Item Master or Stock Settings.")
@@ -1207,6 +1233,7 @@
 	child_item.base_rate = 1 # Initiallize value will update in parent validation
 	child_item.base_amount = 1 # Initiallize value will update in parent validation
 	set_child_tax_template_and_map(item, child_item, p_doc)
+	add_taxes_from_tax_template(child_item, p_doc)
 	return child_item
 
 def validate_and_delete_children(parent, data):
diff --git a/erpnext/selling/doctype/sales_order/test_sales_order.py b/erpnext/selling/doctype/sales_order/test_sales_order.py
index 1ce36dd..2f5f979 100644
--- a/erpnext/selling/doctype/sales_order/test_sales_order.py
+++ b/erpnext/selling/doctype/sales_order/test_sales_order.py
@@ -403,7 +403,7 @@
 
 		trans_item = json.dumps([{'item_code' : '_Test Item', 'rate' : 200, 'qty' : 2, 'docname': so.items[0].name}])
 		self.assertRaises(frappe.ValidationError, update_child_qty_rate,'Sales Order', trans_item, so.name)
-	
+
 	def test_update_child_with_precision(self):
 		from frappe.model.meta import get_field_precision
 		from frappe.custom.doctype.property_setter.property_setter import make_property_setter
@@ -437,7 +437,7 @@
 		self.assertRaises(frappe.ValidationError, update_child_qty_rate,'Sales Order', trans_item, so.name)
 		test_user.remove_roles("Accounts User")
 		frappe.set_user("Administrator")
-	
+
 	def test_update_child_qty_rate_with_workflow(self):
 		from frappe.model.workflow import apply_workflow
 
@@ -506,6 +506,95 @@
 		so.reload()
 		self.assertEqual(so.packed_items[0].qty, 8)
 
+	def test_update_child_with_tax_template(self):
+		"""
+			Test Action: Create a SO with one item having its tax account head already in the SO.
+			Add the same item + new item with tax template via Update Items.
+			Expected result: First Item's tax row is updated. New tax row is added for second Item.
+		"""
+		if not frappe.db.exists("Item", "Test Item with Tax"):
+			make_item("Test Item with Tax", {
+				'is_stock_item': 1,
+			})
+
+		if not frappe.db.exists("Item Tax Template", {"title": 'Test Update Items Template'}):
+			frappe.get_doc({
+				'doctype': 'Item Tax Template',
+				'title': 'Test Update Items Template',
+				'company': '_Test Company',
+				'taxes': [
+					{
+						'tax_type': "_Test Account Service Tax - _TC",
+						'tax_rate': 10,
+					}
+				]
+			}).insert()
+
+		new_item_with_tax = frappe.get_doc("Item", "Test Item with Tax")
+
+		new_item_with_tax.append("taxes", {
+			"item_tax_template": "Test Update Items Template",
+			"valid_from": nowdate()
+		})
+		new_item_with_tax.save()
+
+		tax_template = "_Test Account Excise Duty @ 10"
+		item =  "_Test Item Home Desktop 100"
+		if not frappe.db.exists("Item Tax", {"parent":item, "item_tax_template":tax_template}):
+			item_doc = frappe.get_doc("Item", item)
+			item_doc.append("taxes", {
+				"item_tax_template": tax_template,
+				"valid_from": nowdate()
+			})
+			item_doc.save()
+		else:
+			# update valid from
+			frappe.db.sql("""UPDATE `tabItem Tax` set valid_from = CURDATE()
+				where parent = %(item)s and item_tax_template = %(tax)s""",
+					{"item": item, "tax": tax_template})
+
+		so = make_sales_order(item_code=item, qty=1, do_not_save=1)
+
+		so.append("taxes", {
+			"account_head": "_Test Account Excise Duty - _TC",
+			"charge_type": "On Net Total",
+			"cost_center": "_Test Cost Center - _TC",
+			"description": "Excise Duty",
+			"doctype": "Sales Taxes and Charges",
+			"rate": 10
+		})
+		so.insert()
+		so.submit()
+
+		self.assertEqual(so.taxes[0].tax_amount, 10)
+		self.assertEqual(so.taxes[0].total, 110)
+
+		old_stock_settings_value = frappe.db.get_single_value("Stock Settings", "default_warehouse")
+		frappe.db.set_value("Stock Settings", None, "default_warehouse", "_Test Warehouse - _TC")
+
+		items = json.dumps([
+			{'item_code' : item, 'rate' : 100, 'qty' : 1, 'docname': so.items[0].name},
+			{'item_code' : item, 'rate' : 200, 'qty' : 1}, # added item whose tax account head already exists in PO
+			{'item_code' : new_item_with_tax.name, 'rate' : 100, 'qty' : 1} # added item whose tax account head  is missing in PO
+		])
+		update_child_qty_rate('Sales Order', items, so.name)
+
+		so.reload()
+		self.assertEqual(so.taxes[0].tax_amount, 40)
+		self.assertEqual(so.taxes[0].total, 440)
+		self.assertEqual(so.taxes[1].account_head, "_Test Account Service Tax - _TC")
+		self.assertEqual(so.taxes[1].tax_amount, 40)
+		self.assertEqual(so.taxes[1].total, 480)
+
+		# teardown
+		frappe.db.sql("""UPDATE `tabItem Tax` set valid_from = NULL
+			where parent = %(item)s and item_tax_template = %(tax)s""", {"item": item, "tax": tax_template})
+		so.cancel()
+		so.delete()
+		new_item_with_tax.delete()
+		frappe.get_doc("Item Tax Template", "Test Update Items Template").delete()
+		frappe.db.set_value("Stock Settings", None, "default_warehouse", old_stock_settings_value)
+
 	def test_warehouse_user(self):
 		frappe.permissions.add_user_permission("Warehouse", "_Test Warehouse 1 - _TC", "test@example.com")
 		frappe.permissions.add_user_permission("Warehouse", "_Test Warehouse 2 - _TC1", "test2@example.com")
diff --git a/erpnext/stock/get_item_details.py b/erpnext/stock/get_item_details.py
index 1a7c15e..8d8dcb7 100644
--- a/erpnext/stock/get_item_details.py
+++ b/erpnext/stock/get_item_details.py
@@ -398,6 +398,11 @@
 	else:
 		warehouse = args.get('warehouse')
 
+	if not warehouse:
+		default_warehouse = frappe.db.get_single_value("Stock Settings", "default_warehouse")
+		if frappe.db.get_value("Warehouse", default_warehouse, "company") == args.company:
+			return default_warehouse
+
 	return warehouse
 
 def update_barcode_value(out):