diff --git a/erpnext/accounts/doctype/pos_invoice/test_pos_invoice.py b/erpnext/accounts/doctype/pos_invoice/test_pos_invoice.py
index 514a2ac..1a5920d 100644
--- a/erpnext/accounts/doctype/pos_invoice/test_pos_invoice.py
+++ b/erpnext/accounts/doctype/pos_invoice/test_pos_invoice.py
@@ -285,6 +285,71 @@
 
 		after_redeem_lp_details = get_loyalty_program_details_with_points(inv.customer, company=inv.company, loyalty_program=inv.loyalty_program)
 		self.assertEqual(after_redeem_lp_details.loyalty_points, 9)
+	
+	def test_merging_into_sales_invoice_with_discount(self):
+		from erpnext.accounts.doctype.pos_closing_entry.test_pos_closing_entry import init_user_and_profile
+		from erpnext.accounts.doctype.pos_invoice_merge_log.pos_invoice_merge_log import merge_pos_invoices
+
+		frappe.db.sql("delete from `tabPOS Invoice`")
+		test_user, pos_profile = init_user_and_profile()
+		pos_inv = create_pos_invoice(rate=300, additional_discount_percentage=10, do_not_submit=1)
+		pos_inv.append('payments', {
+			'mode_of_payment': 'Cash', 'account': 'Cash - _TC', 'amount': 300
+		})
+		pos_inv.submit()
+
+		pos_inv2 = create_pos_invoice(rate=3200, do_not_submit=1)
+		pos_inv2.append('payments', {
+			'mode_of_payment': 'Cash', 'account': 'Cash - _TC', 'amount': 3200
+		})
+		pos_inv2.submit()
+
+		merge_pos_invoices()
+
+		pos_inv.load_from_db()
+		sales_invoice = frappe.get_doc("Sales Invoice", pos_inv.consolidated_invoice)
+		self.assertEqual(sales_invoice.grand_total, 3500)
+	
+	def test_merging_into_sales_invoice_with_discount_and_inclusive_tax(self):
+		from erpnext.accounts.doctype.pos_closing_entry.test_pos_closing_entry import init_user_and_profile
+		from erpnext.accounts.doctype.pos_invoice_merge_log.pos_invoice_merge_log import merge_pos_invoices
+
+		frappe.db.sql("delete from `tabPOS Invoice`")
+		test_user, pos_profile = init_user_and_profile()
+		pos_inv = create_pos_invoice(rate=300, do_not_submit=1)
+		pos_inv.append('payments', {
+			'mode_of_payment': 'Cash', 'account': 'Cash - _TC', 'amount': 300
+		})
+		pos_inv.append('taxes', {
+			"charge_type": "On Net Total",
+			"account_head": "_Test Account Service Tax - _TC",
+			"cost_center": "_Test Cost Center - _TC",
+			"description": "Service Tax",
+			"rate": 14,
+			'included_in_print_rate': 1
+		})
+		pos_inv.submit()
+
+		pos_inv2 = create_pos_invoice(rate=300, qty=2, do_not_submit=1)
+		pos_inv2.additional_discount_percentage = 10
+		pos_inv2.append('payments', {
+			'mode_of_payment': 'Cash', 'account': 'Cash - _TC', 'amount': 540
+		})
+		pos_inv2.append('taxes', {
+			"charge_type": "On Net Total",
+			"account_head": "_Test Account Service Tax - _TC",
+			"cost_center": "_Test Cost Center - _TC",
+			"description": "Service Tax",
+			"rate": 14,
+			'included_in_print_rate': 1
+		})
+		pos_inv2.submit()
+
+		merge_pos_invoices()
+
+		pos_inv.load_from_db()
+		sales_invoice = frappe.get_doc("Sales Invoice", pos_inv.consolidated_invoice)
+		self.assertEqual(sales_invoice.rounded_total, 840)
 
 def create_pos_invoice(**args):
 	args = frappe._dict(args)
@@ -294,6 +359,7 @@
 		pos_profile.save()
 
 	pos_inv = frappe.new_doc("POS Invoice")
+	pos_inv.update(args)
 	pos_inv.update_stock = 1
 	pos_inv.is_pos = 1
 	pos_inv.pos_profile = args.pos_profile or pos_profile.name
diff --git a/erpnext/accounts/doctype/pos_invoice_merge_log/pos_invoice_merge_log.py b/erpnext/accounts/doctype/pos_invoice_merge_log/pos_invoice_merge_log.py
index 11b9d25..3a229b1 100644
--- a/erpnext/accounts/doctype/pos_invoice_merge_log/pos_invoice_merge_log.py
+++ b/erpnext/accounts/doctype/pos_invoice_merge_log/pos_invoice_merge_log.py
@@ -96,17 +96,28 @@
 				loyalty_amount_sum += doc.loyalty_amount
 			
 			for item in doc.get('items'):
-				items.append(item)
+				found = False
+				for i in items:
+					if (i.item_code == item.item_code and not i.serial_no and not i.batch_no and
+						i.uom == item.uom and i.net_rate == item.net_rate):
+						found = True
+						i.qty = i.qty + item.qty
+				if not found:
+					item.rate = item.net_rate
+					items.append(item)
 			
 			for tax in doc.get('taxes'):
 				found = False
 				for t in taxes:
-					if t.account_head == tax.account_head and t.cost_center == tax.cost_center and t.rate == tax.rate:
-						t.tax_amount = flt(t.tax_amount) + flt(tax.tax_amount)
-						t.base_tax_amount = flt(t.base_tax_amount) + flt(tax.base_tax_amount)
+					if t.account_head == tax.account_head and t.cost_center == tax.cost_center:
+						t.tax_amount = flt(t.tax_amount) + flt(tax.tax_amount_after_discount_amount)
+						t.base_tax_amount = flt(t.base_tax_amount) + flt(tax.base_tax_amount_after_discount_amount)
 						found = True
 				if not found:
 					tax.charge_type = 'Actual'
+					tax.included_in_print_rate = 0
+					tax.tax_amount = tax.tax_amount_after_discount_amount
+					tax.base_tax_amount = tax.base_tax_amount_after_discount_amount
 					taxes.append(tax)
 
 			for payment in doc.get('payments'):
@@ -127,6 +138,8 @@
 		invoice.set('items', items)
 		invoice.set('payments', payments)
 		invoice.set('taxes', taxes)
+		invoice.additional_discount_percentage = 0
+		invoice.discount_amount = 0.0
 
 		return invoice