fix: keep a dunning claimable until its interest is paid too

a dunning was resolved as soon as the invoiced sum was settled, because the
status was derived from the invoice outstanding alone. paying an invoice
without the interest and fee therefore closed the dunning and lost the
interest: a fresh dunning finds nothing overdue to charge it on.

the dunning amount is never a receivable, it only reaches the ledger as a
negative deduction on a payment entry made from the dunning. link that row
to the dunning so what has been collected is known, and resolve a dunning
only once the invoiced sum and the dunning amount are both paid. a dunning
resolved by hand keeps its status, so waiving the interest stays possible.

the deduction is a company currency field, so book and measure the dunning
amount through base_dunning_amount instead of the transaction currency one.

an interest-only payment leaves every invoice outstanding untouched, so
update the linked dunnings from the payment entry itself instead of relying
on the outstanding amount to change. such a payment also has to be built
from what is left to collect, not from the totals the dunning was raised
with, which are stale by then.

erpnext/accounts/doctype/dunning/dunning.py

@@ -17,7 +17,8 @@ import json
 import frappe
 from frappe import _
 from frappe.contacts.doctype.address.address import get_address_display
-from frappe.utils import getdate
+from frappe.query_builder.functions import Sum
+from frappe.utils import flt, getdate
 
 from erpnext.controllers.accounts_controller import AccountsController
 
@@ -147,6 +148,31 @@ class Dunning(AccountsController):
 			)
 			row.dunning_level = len(past_dunnings) + 1
 
+	def get_unpaid_base_dunning_amount(self):
+		"""Interest and dunning fee that is still to be collected, in company currency."""
+		if not self.base_dunning_amount:
+			return 0.0
+
+		return flt(
+			flt(self.base_dunning_amount) - get_paid_dunning_amount(self.name),
+			self.precision("base_dunning_amount"),
+		)
+
+	def get_unpaid_dunning_amount(self):
+		"""Interest and dunning fee that is still to be collected, in the dunning currency."""
+		return flt(
+			self.get_unpaid_base_dunning_amount() / (flt(self.conversion_rate) or 1),
+			self.precision("dunning_amount"),
+		)
+
+	def get_unpaid_overdue_payments(self):
+		"""Overdue payments with their outstanding as of now, not as of dunning creation."""
+		return [
+			(row, outstanding)
+			for row in self.overdue_payments
+			if (outstanding := get_current_outstanding(row)) > 0
+		]
+
 	def on_cancel(self):
 		super().on_cancel()
 		self.ignore_linked_doctypes = [
@@ -161,6 +187,7 @@ class Dunning(AccountsController):
 			"Unreconcile Payment Entries",
 			"Payment Ledger Entry",
 			"Serial and Batch Bundle",
+			"Payment Entry",
 		]
 
 	@frappe.whitelist()
@@ -259,11 +286,73 @@ def update_linked_dunnings(doc, previous_outstanding_amount):
 			if has_outstanding:
 				break
 
-		new_status = "Resolved" if not has_outstanding else "Unresolved"
+		set_dunning_status(dunning, has_outstanding, respect_manual_resolution=True)
 
-		if dunning.status != new_status:
-			dunning.status = new_status
-			dunning.save()
+
+def update_dunnings_linked_to_payment(payment_entry):
+	"""Refresh dunnings whose interest and fee are settled by this payment."""
+	dunnings = {row.dunning for row in payment_entry.get("deductions") if row.dunning}
+
+	for name in dunnings:
+		dunning = frappe.get_doc("Dunning", name)
+		if dunning.docstatus != 1:
+			continue
+
+		set_dunning_status(dunning, bool(dunning.get_unpaid_overdue_payments()))
+
+
+def set_dunning_status(dunning, has_outstanding_payments: bool, respect_manual_resolution: bool = False):
+	"""A dunning is only resolved once the invoiced sum *and* its interest and fee are paid."""
+	has_unpaid_dunning_amount = dunning.get_unpaid_dunning_amount() > 0
+	new_status = "Unresolved" if has_outstanding_payments or has_unpaid_dunning_amount else "Resolved"
+
+	# resolving by hand waives the interest, only an invoice that is owed again reopens it
+	if respect_manual_resolution and dunning.status == "Resolved" and not has_outstanding_payments:
+		return
+
+	if dunning.status != new_status:
+		dunning.db_set("status", new_status, notify=True)
+
+
+def get_paid_dunning_amount(dunning: str) -> float:
+	"""Interest and fee collected for this dunning, in company currency."""
+	deduction = frappe.qb.DocType("Payment Entry Deduction")
+	payment_entry = frappe.qb.DocType("Payment Entry")
+
+	paid = (
+		frappe.qb.from_(deduction)
+		.join(payment_entry)
+		.on(payment_entry.name == deduction.parent)
+		.select(Sum(deduction.amount))
+		.where((deduction.dunning == dunning) & (payment_entry.docstatus == 1))
+	).run()
+
+	# the dunning amount is booked as a negative deduction, against the income account
+	return -flt(paid[0][0]) if paid else 0.0
+
+
+def get_current_outstanding(overdue_payment) -> float:
+	"""Outstanding of an overdue payment as of now, in the invoice's transaction currency."""
+	invoice = frappe.db.get_value(
+		"Sales Invoice",
+		overdue_payment.sales_invoice,
+		["outstanding_amount", "currency", "party_account_currency"],
+		as_dict=True,
+	)
+	schedule_outstanding = (
+		flt(frappe.db.get_value("Payment Schedule", overdue_payment.payment_schedule, "outstanding"))
+		if overdue_payment.payment_schedule
+		else flt(overdue_payment.outstanding)
+	)
+
+	if flt(invoice.outstanding_amount) <= 0 or schedule_outstanding <= 0:
+		return 0.0
+
+	outstanding = min(schedule_outstanding, flt(overdue_payment.outstanding))
+	if invoice.currency == invoice.party_account_currency:
+		outstanding = min(outstanding, flt(invoice.outstanding_amount))
+
+	return outstanding
 
 
 def get_linked_dunnings_as_per_state(sales_invoice, state):

erpnext/accounts/doctype/payment_entry/payment_entry.py

@@ -209,9 +209,15 @@ class PaymentEntry(AccountsController):
 		self.update_payment_schedule()
 		self.make_gl_entries()
 		self.update_outstanding_amounts()
+		self.update_linked_dunnings()
 		self.set_status()
 		self.trigger_invoice_update_for_subscriptions()
 
+	def update_linked_dunnings(self):
+		from erpnext.accounts.doctype.dunning.dunning import update_dunnings_linked_to_payment
+
+		update_dunnings_linked_to_payment(self)
+
 	def validate_for_repost(self):
 		validate_docs_for_voucher_types(["Payment Entry"])
 		validate_docs_for_deferred_accounting([self.name], [])
@@ -316,6 +322,7 @@ class PaymentEntry(AccountsController):
 		self.update_payment_schedule(cancel=1)
 		self.make_gl_entries(cancel=1)
 		self.update_outstanding_amounts()
+		self.update_linked_dunnings()
 		self.delink_advance_entry_references()
 		self.set_status()
 		self.trigger_invoice_update_for_subscriptions()
@@ -2730,7 +2737,7 @@ def get_payment_entry(
 				pe.append("references", reference)
 		else:
 			if dt == "Dunning":
-				for overdue_payment in doc.overdue_payments:
+				for overdue_payment, outstanding in doc.get_unpaid_overdue_payments():
 					pe.append(
 						"references",
 						{
@@ -2738,21 +2745,23 @@ def get_payment_entry(
 							"reference_name": overdue_payment.sales_invoice,
 							"payment_term": overdue_payment.payment_term,
 							"due_date": overdue_payment.due_date,
-							"total_amount": overdue_payment.outstanding,
-							"outstanding_amount": overdue_payment.outstanding,
-							"allocated_amount": overdue_payment.outstanding,
+							"total_amount": outstanding,
+							"outstanding_amount": outstanding,
+							"allocated_amount": outstanding,
 						},
 					)
 
-				pe.append(
-					"deductions",
-					{
-						"account": doc.income_account,
-						"cost_center": doc.cost_center,
-						"amount": -1 * doc.dunning_amount,
-						"description": _("Interest and/or dunning fee"),
-					},
-				)
+				if (unpaid_dunning_amount := doc.get_unpaid_base_dunning_amount()) > 0:
+					pe.append(
+						"deductions",
+						{
+							"account": doc.income_account,
+							"cost_center": doc.cost_center,
+							"amount": -1 * unpaid_dunning_amount,
+							"description": _("Interest and/or dunning fee"),
+							"dunning": doc.name,
+						},
+					)
 			else:
 				pe.append(
 					"references",
@@ -3045,8 +3054,10 @@ def set_grand_total_and_outstanding_amount(party_amount, dt, party_account_curre
 			grand_total = doc.rounded_total or doc.grand_total
 		outstanding_amount = doc.outstanding_amount
 	elif dt == "Dunning":
-		grand_total = doc.grand_total
-		outstanding_amount = doc.grand_total
+		# only what is left to collect, the totals on the dunning are the ones it was raised with
+		grand_total = sum(outstanding for _row, outstanding in doc.get_unpaid_overdue_payments())
+		grand_total += doc.get_unpaid_dunning_amount()
+		outstanding_amount = grand_total
 	else:
 		if party_account_currency == doc.company_currency:
 			grand_total = flt(doc.get("base_rounded_total") or doc.get("base_grand_total"))

erpnext/accounts/doctype/payment_entry_deduction/payment_entry_deduction.json

@@ -10,7 +10,8 @@
   "amount",
   "column_break_2",
   "is_exchange_gain_loss",
-  "description"
+  "description",
+  "dunning"
  ],
  "fields": [
   {
@@ -55,12 +56,21 @@
    "fieldtype": "Check",
    "label": "System Generated",
    "read_only": 1
+  },
+  {
+   "fieldname": "dunning",
+   "fieldtype": "Link",
+   "label": "Dunning",
+   "no_copy": 1,
+   "options": "Dunning",
+   "print_hide": 1,
+   "read_only": 1
   }
  ],
  "index_web_pages_for_search": 1,
  "istable": 1,
  "links": [],
- "modified": "2026-03-11 14:26:11.312950",
+ "modified": "2026-08-17 11:20:35.482913",
  "modified_by": "Administrator",
  "module": "Accounts",
  "name": "Payment Entry Deduction",

erpnext/accounts/doctype/payment_entry_deduction/payment_entry_deduction.py

@@ -18,6 +18,7 @@ class PaymentEntryDeduction(Document):
 		amount: DF.Currency
 		cost_center: DF.Link
 		description: DF.SmallText | None
+		dunning: DF.Link | None
 		is_exchange_gain_loss: DF.Check
 		parent: DF.Data
 		parentfield: DF.Data