diff --git a/erpnext/patches/v15_0/update_invoice_remarks.py b/erpnext/patches/v15_0/update_invoice_remarks.py
index 7060fe57e31..9146713815f 100644
--- a/erpnext/patches/v15_0/update_invoice_remarks.py
+++ b/erpnext/patches/v15_0/update_invoice_remarks.py
@@ -8,44 +8,142 @@ def execute():
 
 
 def update_sales_invoice_remarks():
-	si_list = frappe.db.get_all(
-		"Sales Invoice",
-		filters={
-			"docstatus": 1,
-			"remarks": "No Remarks",
-			"po_no": ["!=", ""],
-		},
-		fields=["name", "po_no"],
-	)
+	"""
+	Update remarks in Sales Invoice.
+	Some sites may have very large volume of sales invoices.
+	In such cases, updating documents one by one won't be successful, especially during site migration step.
+	Refer to the bug report: https://github.com/frappe/erpnext/issues/43634
+	In this case, a bulk update must be done.
 
-	for doc in si_list:
-		remarks = _("Against Customer Order {0}").format(doc.po_no)
-		update_remarks("Sales Invoice", doc.name, remarks)
+	        Step 1: Update remarks in GL Entries
+	        Step 2: Update remarks in Payment Ledger Entries
+	        Step 3: Update remarks in Sales Invoice	- Should be last step
+	"""
+
+	###	Step 1:	Update remarks in GL Entries
+	update_sales_invoice_gle_remarks()
+
+	###	Step 2: Update remarks in Payment Ledger Entries
+	update_sales_invoice_ple_remarks()
+
+	###	Step 3: Update remarks in Sales Invoice
+	update_query = """
+		UPDATE `tabSales Invoice`
+		SET remarks = concat('Against Customer Order ', po_no)
+		WHERE po_no <> '' AND docstatus = %(docstatus)s and remarks = %(remarks)s
+	"""
+
+	# Data for update query
+	values = {"remarks": "No Remarks", "docstatus": 1}
+
+	# Execute query
+	frappe.db.sql(update_query, values=values, as_dict=0)
 
 
 def update_purchase_invoice_remarks():
-	pi_list = frappe.db.get_all(
-		"Purchase Invoice",
-		filters={
-			"docstatus": 1,
-			"remarks": "No Remarks",
-			"bill_no": ["!=", ""],
-		},
-		fields=["name", "bill_no"],
-	)
+	"""
+	Update remarks in Purchase Invoice.
+	Some sites may have very large volume of purchase invoices.
+	In such cases, updating documents one by one wont be successful, especially during site migration step.
+	Refer to the bug report: https://github.com/frappe/erpnext/issues/43634
+	In this case, a bulk update must be done.
 
-	for doc in pi_list:
-		remarks = _("Against Supplier Invoice {0}").format(doc.bill_no)
-		update_remarks("Purchase Invoice", doc.name, remarks)
+	        Step 1: Update remarks in GL Entries
+	        Step 2: Update remarks in Payment Ledger Entries
+	        Step 3: Update remarks in Purchase Invoice - Should be last step
+	"""
+
+	###	Step 1:	Update remarks in GL Entries
+	update_purchase_invoice_gle_remarks()
+
+	###	Step 2:	Update remarks in Payment Ledger Entries
+	update_purchase_invoice_ple_remarks()
+
+	###	Step 3: Update remarks in Purchase Invoice
+	update_query = """
+		UPDATE `tabPurchase Invoice`
+		SET remarks = concat('Against Supplier Invoice ', bill_no)
+		WHERE bill_no <> '' AND docstatus = %(docstatus)s and remarks = %(remarks)s
+	"""
+
+	# Data for update query
+	values = {"remarks": "No Remarks", "docstatus": 1}
+
+	# Execute query
+	frappe.db.sql(update_query, values=values, as_dict=0)
 
 
-def update_remarks(doctype, docname, remarks):
-	filters = {
-		"voucher_type": doctype,
-		"remarks": "No Remarks",
-		"voucher_no": docname,
-	}
+def update_sales_invoice_gle_remarks():
+	##	Update query to update GL Entry - Updates all entries which are for Sales Invoice with No Remarks
+	update_query = """
+		UPDATE
+		`tabGL Entry` as gle
+		INNER JOIN `tabSales Invoice` as si
+		ON gle.voucher_type = 'Sales Invoice' AND gle.voucher_no = si.name AND gle.remarks = %(remarks)s
+		SET
+		gle.remarks = concat('Against Customer Order ', si.po_no)
+		WHERE si.po_no <> '' AND si.docstatus = %(docstatus)s and si.remarks = %(remarks)s
+	"""
 
-	frappe.db.set_value(doctype, docname, "remarks", remarks)
-	frappe.db.set_value("GL Entry", filters, "remarks", remarks)
-	frappe.db.set_value("Payment Ledger Entry", filters, "remarks", remarks)
+	# Data for update query
+	values = {"remarks": "No Remarks", "docstatus": 1}
+
+	# Execute query
+	frappe.db.sql(update_query, values=values, as_dict=0)
+
+
+def update_sales_invoice_ple_remarks():
+	##	Update query to update Payment Ledger Entry - Updates all entries which are for Sales Invoice with No Remarks
+	update_query = """
+		UPDATE
+		`tabPayment Ledger Entry` as ple
+		INNER JOIN `tabSales Invoice` as si
+		ON ple.voucher_type = 'Sales Invoice' AND ple.voucher_no = si.name AND ple.remarks = %(remarks)s
+		SET
+		ple.remarks = concat('Against Customer Order ', si.po_no)
+		WHERE si.po_no <> '' AND si.docstatus = %(docstatus)s and si.remarks = %(remarks)s
+	"""
+
+	### Data for update query
+	values = {"remarks": "No Remarks", "docstatus": 1}
+
+	### Execute query
+	frappe.db.sql(update_query, values=values, as_dict=0)
+
+
+def update_purchase_invoice_gle_remarks():
+	###	Query to update GL Entry - Updates all entries which are for Purchase Invoice with No Remarks
+	update_query = """
+		UPDATE
+		`tabGL Entry` as gle
+		INNER JOIN `tabPurchase Invoice` as pi
+		ON gle.voucher_type = 'Purchase Invoice' AND gle.voucher_no = pi.name AND gle.remarks = %(remarks)s
+		SET
+		gle.remarks = concat('Against Supplier Invoice ', pi.bill_no)
+		WHERE pi.bill_no <> '' AND pi.docstatus = %(docstatus)s and pi.remarks = %(remarks)s
+	"""
+
+	### Data for update query
+	values = {"remarks": "No Remarks", "docstatus": 1}
+
+	### Execute query
+	frappe.db.sql(update_query, values=values, as_dict=0)
+
+
+def update_purchase_invoice_ple_remarks():
+	###	Query to update Payment Ledger Entry - Updates all entries which are for Purchase Invoice with No Remarks
+	update_query = """
+		UPDATE
+		`tabPayment Ledger Entry` as ple
+		INNER JOIN `tabPurchase Invoice` as pi
+		ON ple.voucher_type = 'Purchase Invoice' AND ple.voucher_no = pi.name AND ple.remarks = %(remarks)s
+		SET
+		ple.remarks = concat('Against Supplier Invoice ', pi.bill_no)
+		WHERE pi.bill_no <> '' AND pi.docstatus = %(docstatus)s and pi.remarks = %(remarks)s
+	"""
+
+	### Data for update query
+	values = {"remarks": "No Remarks", "docstatus": 1}
+
+	### Execute query
+	frappe.db.sql(update_query, values=values, as_dict=0)