diff --git a/erpnext/regional/doctype/lower_deduction_certificate/lower_deduction_certificate.py b/erpnext/regional/doctype/lower_deduction_certificate/lower_deduction_certificate.py
index 7afbc00..821e017 100644
--- a/erpnext/regional/doctype/lower_deduction_certificate/lower_deduction_certificate.py
+++ b/erpnext/regional/doctype/lower_deduction_certificate/lower_deduction_certificate.py
@@ -31,7 +31,7 @@
 			<= fiscal_year.year_end_date):
 			frappe.throw(_("Valid Upto date not in Fiscal Year {0}").format(frappe.bold(self.fiscal_year)))
 
-	def tax_withholding_category(self):
+	def validate_supplier_against_tax_category(self):
 		duplicate_certificate = frappe.db.get_value('Lower Deduction Certificate',
 			{'supplier': self.supplier, 'tax_withholding_category': self.tax_withholding_category, 'name': ("!=", self.name)},
 			['name', 'valid_from', 'valid_upto'], as_dict=True)