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 32ad4cb..3e0ba9a 100644
--- a/erpnext/accounts/doctype/tax_withholding_category/tax_withholding_category.py
+++ b/erpnext/accounts/doctype/tax_withholding_category/tax_withholding_category.py
@@ -12,37 +12,54 @@
 class TaxWithholdingCategory(Document):
 	pass
 
-def get_party_tax_withholding_details(ref_doc, tax_withholding_category=None):
+def get_party_details(ref_doc):
+	party_type, party = '', ''
 
+	if ref_doc.doctype == 'Sales Invoice':
+		party_type = 'Customer'
+		party = ref_doc.customer
+	else:
+		party_type = 'Supplier'
+		party = ref_doc.supplier
+	
+	return party_type, party
+
+def get_party_tax_withholding_details(ref_doc, tax_withholding_category=None):
 	pan_no = ''
-	suppliers = []
+	parties = []
+	party_type, party = get_party_details(ref_doc)
 
 	if not tax_withholding_category:
-		tax_withholding_category, pan_no = frappe.db.get_value('Supplier', ref_doc.supplier, ['tax_withholding_category', 'pan'])
+		tax_withholding_category, pan_no = frappe.db.get_value(party_type, party, ['tax_withholding_category', 'pan'])
 
 	if not tax_withholding_category:
 		return
 
+	# if tax_withholding_category passed as an argument but not pan_no
 	if not pan_no:
-		pan_no = frappe.db.get_value('Supplier', ref_doc.supplier, 'pan')
+		pan_no = frappe.db.get_value(party_type, party, 'pan')
 
 	# Get others suppliers with the same PAN No
 	if pan_no:
-		suppliers = [d.name for d in  frappe.get_all('Supplier', fields=['name'], filters={'pan': pan_no})]
+		parties = frappe.get_all(party_type, filters={ 'pan': pan_no }, pluck='name')
 
-	if not suppliers:
-		suppliers.append(ref_doc.supplier)
+	if not parties:
+		parties.append(party)
 
-	fy = get_fiscal_year(ref_doc.posting_date, company=ref_doc.company)
-	tax_details = get_tax_withholding_details(tax_withholding_category, fy[0], ref_doc.company)
+	fiscal_year = get_fiscal_year(ref_doc.posting_date, company=ref_doc.company)
+	tax_details = get_tax_withholding_details(tax_withholding_category, fiscal_year[0], ref_doc.company)
+
 	if not tax_details:
 		frappe.throw(_('Please set associated account in Tax Withholding Category {0} against Company {1}')
 			.format(tax_withholding_category, ref_doc.company))
 
-	tds_amount = get_tds_amount(suppliers, ref_doc.net_total, ref_doc.company,
-		tax_details, fy,  ref_doc.posting_date, pan_no)
+	tax_amount = get_tax_amount(
+		party_type, parties,
+		ref_doc, tax_details,
+		fiscal_year, pan_no
+	)
 
-	tax_row = get_tax_row(tax_details, tds_amount)
+	tax_row = get_tax_row(tax_details, tax_amount)
 
 	return tax_row
 
@@ -69,147 +86,162 @@
 
 	frappe.throw(_("No Tax Withholding data found for the current Fiscal Year."))
 
-def get_tax_row(tax_details, tds_amount):
-
+def get_tax_row(tax_details, tax_amount):
 	return {
 		"category": "Total",
 		"add_deduct_tax": "Deduct",
 		"charge_type": "Actual",
 		"account_head": tax_details.account_head,
 		"description": tax_details.description,
-		"tax_amount": tds_amount
+		"tax_amount": tax_amount
 	}
 
-def get_tds_amount(suppliers, net_total, company, tax_details, fiscal_year_details, posting_date, pan_no=None):
-	fiscal_year, year_start_date, year_end_date = fiscal_year_details
-	tds_amount = 0
-	tds_deducted = 0
-
-	def _get_tds(amount, rate):
-		if amount <= 0:
-			return 0
-
-		return amount * rate / 100
-
-	ldc_name = frappe.db.get_value('Lower Deduction Certificate',
-		{
-			'pan_no': pan_no,
-			'fiscal_year': fiscal_year
-		}, 'name')
-	ldc = ''
-
+def get_lower_deduction_certificate(fiscal_year, pan_no):
+	ldc_name = frappe.db.get_value('Lower Deduction Certificate', { 'pan_no': pan_no, 'fiscal_year': fiscal_year }, 'name')
 	if ldc_name:
-		ldc = frappe.get_doc('Lower Deduction Certificate', ldc_name)
+		return frappe.get_doc('Lower Deduction Certificate', ldc_name)
 
-	entries = frappe.db.sql("""
-			select voucher_no, credit
-			from `tabGL Entry`
-			where company = %s and
-			party in %s and fiscal_year=%s and credit > 0
-			and is_opening = 'No'
-		""", (company, tuple(suppliers), fiscal_year), as_dict=1)
+def get_tax_amount(party_type, parties, ref_doc, tax_details, fiscal_year_details, pan_no=None):
+	fiscal_year = fiscal_year_details[0]
 
-	vouchers = [d.voucher_no for d in entries]
-	advance_vouchers = get_advance_vouchers(suppliers, fiscal_year=fiscal_year, company=company)
+	vouchers = get_invoice_vouchers(parties, fiscal_year, ref_doc.company, party_type=party_type) or [""]
+	advance_vouchers = get_advance_vouchers(parties, fiscal_year, ref_doc.company, party_type=party_type)
+	tax_vouchers = vouchers + advance_vouchers
 
-	tds_vouchers = vouchers + advance_vouchers
+	tax_deducted = 0
+	dr_or_cr = 'credit' if party_type == 'Supplier' else 'debit'
+	if tax_vouchers:
+		filters = {
+			dr_or_cr: ['>', 0],
+			'account': tax_details.account_head,
+			'fiscal_year': fiscal_year,
+			'voucher_no': ['in', tax_vouchers],
+			'is_cancelled': 0
+		}
+		field = "sum({})".format(dr_or_cr)
 
-	if tds_vouchers:
-		tds_deducted = frappe.db.sql("""
-			SELECT sum(credit) FROM `tabGL Entry`
-			WHERE
-				account=%s and fiscal_year=%s and credit > 0
-				and voucher_no in ({0})""". format(','.join(['%s'] * len(tds_vouchers))),
-				((tax_details.account_head, fiscal_year) + tuple(tds_vouchers)))
+		tax_deducted = frappe.db.get_value('GL Entry', filters, field) or 0.0
 
-		tds_deducted = tds_deducted[0][0] if tds_deducted and tds_deducted[0][0] else 0
+	tax_amount = 0
+	if party_type == 'Supplier':
+		net_total = ref_doc.net_total
+		posting_date = ref_doc.posting_date
+		ldc = get_lower_deduction_certificate(fiscal_year, pan_no)
 
-	if tds_deducted:
-		if ldc:
-			limit_consumed = frappe.db.get_value('Purchase Invoice',
-				{
-					'supplier': ('in', suppliers),
-					'apply_tds': 1,
-					'docstatus': 1
-				}, 'sum(net_total)')
-
-		if ldc and is_valid_certificate(ldc.valid_from, ldc.valid_upto, posting_date, limit_consumed, net_total,
-			ldc.certificate_limit):
-
-			tds_amount = get_ltds_amount(net_total, limit_consumed, ldc.certificate_limit, ldc.rate, tax_details)
-		else:
-			tds_amount = _get_tds(net_total, tax_details.rate)
-	else:
-		supplier_credit_amount = frappe.get_all('Purchase Invoice',
-			fields = ['sum(net_total)'],
-			filters = {'name': ('in', vouchers), 'docstatus': 1, "apply_tds": 1}, as_list=1)
-
-		supplier_credit_amount = (supplier_credit_amount[0][0]
-			if supplier_credit_amount and supplier_credit_amount[0][0] else 0)
-
-		jv_supplier_credit_amt = frappe.get_all('Journal Entry Account',
-			fields = ['sum(credit_in_account_currency)'],
-			filters = {
-				'parent': ('in', vouchers), 'docstatus': 1,
-				'party': ('in', suppliers),
-				'reference_type': ('not in', ['Purchase Invoice'])
-			}, as_list=1)
-
-		supplier_credit_amount += (jv_supplier_credit_amt[0][0]
-			if jv_supplier_credit_amt and jv_supplier_credit_amt[0][0] else 0)
-
-		supplier_credit_amount += net_total
-
-		debit_note_amount = get_debit_note_amount(suppliers, year_start_date, year_end_date)
-		supplier_credit_amount -= debit_note_amount
-
-		if ((tax_details.get('threshold', 0) and supplier_credit_amount >= tax_details.threshold)
-			or (tax_details.get('cumulative_threshold', 0) and supplier_credit_amount >= tax_details.cumulative_threshold)):
-
-			if ldc and is_valid_certificate(ldc.valid_from, ldc.valid_upto, posting_date, tds_deducted, net_total,
-				ldc.certificate_limit):
-				tds_amount = get_ltds_amount(supplier_credit_amount, 0, ldc.certificate_limit, ldc.rate,
-					tax_details)
+		if tax_deducted:
+			if ldc:
+				tax_amount = get_tds_amount_from_ldc(ldc, parties, fiscal_year, pan_no, tax_details, posting_date, net_total)
 			else:
-				tds_amount = _get_tds(supplier_credit_amount, tax_details.rate)
+				tax_amount = net_total * tax_details.rate / 100 if net_total > 0 else 0
+		else:
+			tax_amount = get_tds_amount(
+				ldc, parties, ref_doc, tax_details,
+				fiscal_year_details, vouchers
+			)
+
+	return tax_amount
+
+def get_invoice_vouchers(parties, fiscal_year, company, party_type='Supplier'):
+	dr_or_cr = 'credit' if party_type == 'Supplier' else 'debit'
+
+	filters = {
+		dr_or_cr: ['>', 0],
+		'company': company,
+		'party_type': party_type,
+		'party': ['in', parties],
+		'fiscal_year': fiscal_year,
+		'is_opening': 'No',
+		'is_cancelled': 0
+	}
+
+	return frappe.get_all('GL Entry', filters=filters, distinct=1, pluck="voucher_no")
+
+def get_advance_vouchers(parties, fiscal_year=None, company=None, from_date=None, to_date=None, party_type='Supplier'):
+	# for advance vouchers, debit and credit is reversed
+	dr_or_cr = 'debit' if party_type == 'Supplier' else 'credit'
+
+	filters = {
+		dr_or_cr: ['>', 0],
+		'party_type': party_type,
+		'party': ['in', parties],
+		'is_opening': 'No',
+		'is_cancelled': 0
+	}
+
+	if fiscal_year:
+		filters['fiscal_year'] = fiscal_year
+	if company:
+		filters['company'] = company
+	if from_date and to_date:
+		filters['posting_date'] = ['between', (from_date, to_date)]
+
+	return frappe.get_all('GL Entry', filters=filters, distinct=1, pluck='voucher_no')
+
+def get_tds_amount(ldc, parties, ref_doc, tax_details, fiscal_year_details, vouchers):
+	tds_amount = 0
+
+	supp_credit_amt = frappe.db.get_value('Purchase Invoice', {
+		'name': ('in', vouchers), 'docstatus': 1, 'apply_tds': 1
+	}, 'sum(net_total)') or 0.0
+
+	supp_jv_credit_amt = frappe.db.get_value('Journal Entry Account', {
+		'parent': ('in', vouchers), 'docstatus': 1,
+		'party': ('in', parties), 'reference_type': ('!=', 'Purchase Invoice')
+	}, 'sum(credit_in_account_currency)') or 0.0
+
+	supp_credit_amt += supp_jv_credit_amt
+	supp_credit_amt += ref_doc.net_total
+
+	debit_note_amount = get_debit_note_amount(parties, fiscal_year_details, ref_doc.company)
+	supp_credit_amt -= debit_note_amount
+
+	threshold = tax_details.get('threshold', 0)
+	cumulative_threshold = tax_details.get('cumulative_threshold', 0)
+
+	if ((threshold and supp_credit_amt >= threshold) or (cumulative_threshold and supp_credit_amt >= cumulative_threshold)):
+		if ldc and is_valid_certificate(
+			ldc.valid_from, ldc.valid_upto,
+			ref_doc.posting_date, tax_deducted,
+			net_total, ldc.certificate_limit
+		):
+			tds_amount = get_ltds_amount(supp_credit_amt, 0, ldc.certificate_limit, ldc.rate, tax_details)
+		else:
+			tds_amount = supp_credit_amt * tax_details.rate / 100 if supp_credit_amt > 0 else 0
 
 	return tds_amount
 
-def get_advance_vouchers(suppliers, fiscal_year=None, company=None, from_date=None, to_date=None):
-	condition = "fiscal_year=%s" % fiscal_year
+def get_tds_amount_from_ldc(ldc, parties, fiscal_year, pan_no, tax_details, posting_date, net_total):
+	tds_amount = 0
+	limit_consumed = frappe.db.get_value('Purchase Invoice', {
+		'supplier': ('in', parties),
+		'apply_tds': 1,
+		'docstatus': 1
+	}, 'sum(net_total)')
+
+	if is_valid_certificate(
+		ldc.valid_from, ldc.valid_upto,
+		posting_date, limit_consumed,
+		net_total, ldc.certificate_limit
+	):
+		tds_amount = get_ltds_amount(net_total, limit_consumed, ldc.certificate_limit, ldc.rate, tax_details)
+	
+	return tds_amount
+
+def get_debit_note_amount(suppliers, fiscal_year_details, company=None):
+	_, year_start_date, year_end_date = fiscal_year_details
+
+	filters = {
+		'supplier': ['in', suppliers],
+		'is_return': 1,
+		'docstatus': 1,
+		'posting_date': ['between', (year_start_date, year_end_date)]
+	}
+	fields = ['abs(sum(net_total)) as net_total']
 
 	if company:
-		condition += "and company =%s" % (company)
-	if from_date and to_date:
-		condition += "and posting_date between %s and %s" % (from_date, to_date)
+		filters['company'] = company
 
-	## Appending the same supplier again if length of suppliers list is 1
-	## since tuple of single element list contains None, For example ('Test Supplier 1', )
-	## and the below query fails
-	if len(suppliers) == 1:
-		suppliers.append(suppliers[0])
-
-	return frappe.db.sql_list("""
-		select distinct voucher_no
-		from `tabGL Entry`
-		where party in %s and %s and debit > 0
-		and is_opening = 'No'
-	""", (tuple(suppliers), condition)) or []
-
-def get_debit_note_amount(suppliers, year_start_date, year_end_date, company=None):
-	condition = "and 1=1"
-	if company:
-		condition = " and company=%s " % company
-
-	if len(suppliers) == 1:
-		suppliers.append(suppliers[0])
-
-	return flt(frappe.db.sql("""
-		select abs(sum(net_total))
-		from `tabPurchase Invoice`
-		where supplier in %s and is_return=1 and docstatus=1
-			and posting_date between %s and %s %s
-	""", (tuple(suppliers), year_start_date, year_end_date, condition)))
+	return frappe.get_all('Purchase Invoice', filters, fields)[0].get('net_total') or 0.0
 
 def get_ltds_amount(current_amount, deducted_amount, certificate_limit, rate, tax_details):
 	if current_amount < (certificate_limit - deducted_amount):
@@ -227,4 +259,4 @@
 			certificate_limit > deducted_amount):
 		valid = True
 
-	return valid
\ No newline at end of file
+	return valid
diff --git a/erpnext/accounts/doctype/tax_withholding_category/test_tax_withholding_category.py b/erpnext/accounts/doctype/tax_withholding_category/test_tax_withholding_category.py
index ef77674..2b387f9 100644
--- a/erpnext/accounts/doctype/tax_withholding_category/test_tax_withholding_category.py
+++ b/erpnext/accounts/doctype/tax_withholding_category/test_tax_withholding_category.py
@@ -18,6 +18,17 @@
 		create_records()
 		create_tax_with_holding_category()
 
+	def tearDown(self):
+		frappe.db.sql('delete from `tabPurchase Invoice` where supplier = "Test TDS Supplier"')
+		frappe.db.sql('delete from `tabPurchase Invoice` where supplier = "Test TDS Supplier1"')
+		frappe.db.sql('delete from `tabPurchase Invoice` where supplier = "Test TDS Supplier2"')
+		frappe.db.sql('delete from `tabPurchase Invoice` where supplier = "Test TDS Supplier ABC"')
+
+		frappe.db.sql('delete from `tabGL Entry` where party = "Test TDS Supplier"')
+		frappe.db.sql('delete from `tabGL Entry` where party = "Test TDS Supplier1"')
+		frappe.db.sql('delete from `tabGL Entry` where party = "Test TDS Supplier2"')
+		frappe.db.sql('delete from `tabGL Entry` where party = "Test TDS Supplier ABC"')
+
 	def test_cumulative_threshold_tds(self):
 		frappe.db.set_value("Supplier", "Test TDS Supplier", "tax_withholding_category", "Cumulative Threshold TDS")
 		invoices = []