diff --git a/erpnext/accounts/doctype/tax_withholding_category/tax_withholding_category.py b/erpnext/accounts/doctype/tax_withholding_category/tax_withholding_category.py
index 35c2f84..a519d8b 100644
--- a/erpnext/accounts/doctype/tax_withholding_category/tax_withholding_category.py
+++ b/erpnext/accounts/doctype/tax_withholding_category/tax_withholding_category.py
@@ -34,7 +34,9 @@
 
 	def validate_thresholds(self):
 		for d in self.get("rates"):
-			if d.cumulative_threshold and d.cumulative_threshold < d.single_threshold:
+			if (
+				d.cumulative_threshold and d.single_threshold and d.cumulative_threshold < d.single_threshold
+			):
 				frappe.throw(
 					_("Row #{0}: Cumulative threshold cannot be less than Single Transaction threshold").format(
 						d.idx