Merge pull request #39633 from frappe/mergify/bp/version-15-hotfix/pr-39559

fix: prevent Return Invoices(Credit/Debit Note) from using a different account  (backport #39559)

erpnext/accounts/doctype/purchase_invoice/test_purchase_invoice.py

@@ -1985,6 +1985,21 @@ class TestPurchaseInvoice(FrappeTestCase, StockTestMixin):
 
 		self.assertEqual(pi.items[0].cost_center, "_Test Cost Center Buying - _TC")
 
+	def test_debit_note_with_account_mismatch(self):
+		new_creditors = create_account(
+			parent_account="Accounts Payable - _TC",
+			account_name="Creditors 2",
+			company="_Test Company",
+			account_type="Payable",
+		)
+		pi = make_purchase_invoice(qty=1, rate=1000)
+		dr_note = make_purchase_invoice(
+			qty=-1, rate=1000, is_return=1, return_against=pi.name, do_not_save=True
+		)
+		dr_note.credit_to = new_creditors
+
+		self.assertRaises(frappe.ValidationError, dr_note.save)
+
 	def test_debit_note_without_item(self):
 		pi = make_purchase_invoice(item_name="_Test Item", qty=10, do_not_submit=True)
 		pi.items[0].item_code = ""

erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py

@@ -1533,6 +1533,19 @@ class TestSalesInvoice(FrappeTestCase):
 		self.assertEqual(frappe.db.get_value("Sales Invoice", si1.name, "outstanding_amount"), -1000)
 		self.assertEqual(frappe.db.get_value("Sales Invoice", si.name, "outstanding_amount"), 2500)
 
+	def test_return_invoice_with_account_mismatch(self):
+		debtors2 = create_account(
+			parent_account="Accounts Receivable - _TC",
+			account_name="Debtors 2",
+			company="_Test Company",
+			account_type="Receivable",
+		)
+		si = create_sales_invoice(qty=1, rate=1000)
+		cr_note = create_sales_invoice(
+			qty=-1, rate=1000, is_return=1, return_against=si.name, debit_to=debtors2, do_not_save=True
+		)
+		self.assertRaises(frappe.ValidationError, cr_note.save)
+
 	def test_gle_made_when_asset_is_returned(self):
 		create_asset_data()
 		asset = create_asset(item_code="Macbook Pro")

erpnext/controllers/accounts_controller.py

@@ -202,6 +202,7 @@ class AccountsController(TransactionBase):
 		self.validate_party()
 		self.validate_currency()
 		self.validate_party_account_currency()
+		self.validate_return_against_account()
 
 		if self.doctype in ["Purchase Invoice", "Sales Invoice"]:
 			if invalid_advances := [
@@ -350,6 +351,20 @@ class AccountsController(TransactionBase):
 		for bundle in bundles:
 			frappe.delete_doc("Serial and Batch Bundle", bundle.name)
 
+	def validate_return_against_account(self):
+		if (
+			self.doctype in ["Sales Invoice", "Purchase Invoice"] and self.is_return and self.return_against
+		):
+			cr_dr_account_field = "debit_to" if self.doctype == "Sales Invoice" else "credit_to"
+			cr_dr_account_label = "Debit To" if self.doctype == "Sales Invoice" else "Credit To"
+			cr_dr_account = self.get(cr_dr_account_field)
+			if frappe.get_value(self.doctype, self.return_against, cr_dr_account_field) != cr_dr_account:
+				frappe.throw(
+					_("'{0}' account: '{1}' should match the Return Against Invoice").format(
+						frappe.bold(cr_dr_account_label), frappe.bold(cr_dr_account)
+					)
+				)
+
 	def validate_deferred_income_expense_account(self):
 		field_map = {
 			"Sales Invoice": "deferred_revenue_account",