diff --git a/erpnext/accounts/services/child_item_update.py b/erpnext/accounts/services/child_item_update.py
deleted file mode 100644
index d66c5621f7a..00000000000
--- a/erpnext/accounts/services/child_item_update.py
+++ /dev/null
@@ -1,618 +0,0 @@
-# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
-# License: GNU General Public License v3. See license.txt
-
-"""Child item update service: ChildItemUpdater class and helpers for the update_child_qty_rate API."""
-
-import frappe
-from frappe import _
-from frappe.model.workflow import get_workflow_name
-from frappe.utils import flt, get_link_to_form, getdate
-
-from erpnext.accounts.doctype.accounting_dimension.accounting_dimension import get_accounting_dimensions
-from erpnext.buying.utils import update_last_purchase_rate
-from erpnext.stock.doctype.packed_item.packed_item import make_packing_list
-from erpnext.stock.get_item_details import (
-	get_bin_details,
-	get_conversion_factor,
-	get_item_warehouse_,
-)
-from erpnext.stock.utils import (
-	is_group_warehouse,
-	validate_disabled_warehouse,
-	validate_warehouse_company,
-)
-
-
-class ChildItemUpdater:
-	"""Validates and applies item-level edits on submitted orders and quotations."""
-
-	def __init__(self, parent_doctype: str, parent_doctype_name: str, child_docname: str = "items"):
-		self.parent_doctype = parent_doctype
-		self.parent_doctype_name = parent_doctype_name
-		self.child_docname = child_docname
-		self.parent = frappe.get_doc(parent_doctype, parent_doctype_name)
-		self.allow_zero_qty = get_allow_zero_qty(parent_doctype)
-		self._ordered_items: dict | None = None
-		self._purchased_items: dict | None = None
-
-	def update(self, trans_items: str | list) -> None:
-		"""Process item additions, edits, and deletions from trans_items JSON."""
-		from erpnext.buying.doctype.supplier_quotation.supplier_quotation import get_purchased_items
-		from erpnext.selling.doctype.quotation.mapper import get_ordered_items
-
-		data = frappe.parse_json(trans_items)
-		any_qty_changed = False
-		items_added_or_removed = False
-		any_conversion_factor_changed = False
-
-		self._check_permissions("write")
-
-		if self.parent_doctype == "Quotation":
-			self._ordered_items = get_ordered_items(self.parent.name)
-			items_added_or_removed |= validate_and_delete_children(self.parent, data, self._ordered_items)
-		elif self.parent_doctype == "Supplier Quotation":
-			self._purchased_items = get_purchased_items(self.parent.name)
-			items_added_or_removed |= validate_and_delete_children(self.parent, data, self._purchased_items)
-		else:
-			items_added_or_removed |= validate_and_delete_children(self.parent, data)
-
-		for d in data:
-			new_child_flag = False
-			rate_unchanged = None
-
-			if not d.get("item_code"):
-				continue
-
-			if not d.get("docname"):
-				new_child_flag = True
-				items_added_or_removed = True
-				self._check_permissions("create")
-				child_item = self._get_new_child_item(d)
-			else:
-				self._check_permissions("write")
-				child_item = frappe.get_doc(self.parent_doctype + " Item", d.get("docname"))
-
-				change_state = get_child_item_change_state(self.parent_doctype, child_item, d)
-				rate_unchanged = change_state.rate_unchanged
-				any_conversion_factor_changed |= not change_state.conversion_factor_unchanged
-				if is_child_item_unchanged(change_state):
-					continue
-
-			self._validate_quantity_and_rate(child_item, d, rate_unchanged)
-
-			if flt(child_item.get("qty")) != flt(d.get("qty")):
-				any_qty_changed = True
-
-			if self.parent.doctype in ("Sales Order", "Purchase Order") and self.parent.is_subcontracted:
-				self._validate_fg_item_for_subcontracting(d, new_child_flag)
-				child_item.fg_item_qty = flt(d["fg_item_qty"])
-				if new_child_flag:
-					child_item.fg_item = d["fg_item"]
-
-			child_item.qty = flt(d.get("qty"))
-			child_item.description = d.get("description")
-			update_child_item_rate_and_discount(
-				self.parent_doctype, child_item, d, self.allow_zero_qty, rate_unchanged=rate_unchanged
-			)
-			update_child_item_uom_and_weight(child_item, d)
-
-			if d.get("delivery_date") and self.parent_doctype == "Sales Order":
-				child_item.delivery_date = d.get("delivery_date")
-
-			if d.get("schedule_date") and self.parent_doctype == "Purchase Order":
-				child_item.schedule_date = d.get("schedule_date")
-
-			if d.get("bom_no") and self.parent_doctype == "Sales Order":
-				child_item.bom_no = d.get("bom_no")
-
-			child_item.flags.ignore_validate_update_after_submit = True
-			if new_child_flag:
-				self.parent.load_from_db()
-				child_item.idx = len(self.parent.items) + 1
-				child_item.insert()
-			else:
-				child_item.save(ignore_permissions=True)
-
-		self._post_update(any_qty_changed, items_added_or_removed, any_conversion_factor_changed)
-
-	def _post_update(
-		self, any_qty_changed: bool, items_added_or_removed: bool, any_conversion_factor_changed: bool
-	) -> None:
-		parent = self.parent
-		parent.reload()
-		parent.flags.ignore_validate_update_after_submit = True
-		parent.set_qty_as_per_stock_uom()
-		parent.calculate_taxes_and_totals()
-		parent.set_total_in_words()
-
-		if self.parent_doctype == "Sales Order" and not parent.is_subcontracted:
-			make_packing_list(parent)
-			parent.set_gross_profit()
-
-		frappe.get_cached_doc("Authorization Control").validate_approving_authority(
-			parent.doctype, parent.company, parent.base_grand_total
-		)
-
-		if self.parent_doctype != "Supplier Quotation":
-			from erpnext.accounts.services.payment_schedule import PaymentScheduleService
-
-			PaymentScheduleService(parent).set_payment_schedule()
-
-		if self.parent_doctype == "Purchase Order":
-			parent.validate_minimum_order_qty()
-			parent.validate_budget()
-			if parent.is_against_so():
-				parent.update_status_updater()
-		elif self.parent_doctype == "Sales Order":
-			parent.check_credit_limit()
-
-		for idx, row in enumerate(parent.get(self.child_docname), start=1):
-			row.idx = idx
-
-		parent.save()
-
-		if self.parent_doctype == "Purchase Order":
-			update_last_purchase_rate(parent, is_submit=1)
-
-			if any_qty_changed or items_added_or_removed or any_conversion_factor_changed:
-				parent.update_prevdoc_status()
-
-			parent.update_requested_qty()
-			parent.update_ordered_qty()
-			parent.update_ordered_and_reserved_qty()
-			parent.update_receiving_percentage()
-
-			if parent.is_subcontracted and not parent.can_update_items():
-				frappe.throw(
-					_(
-						"Items cannot be updated as Subcontracting Order is created against the Purchase Order {0}."
-					).format(frappe.bold(parent.name))
-				)
-
-		elif self.parent_doctype == "Sales Order":
-			if parent.is_subcontracted and not parent.can_update_items():
-				frappe.throw(
-					_(
-						"Items cannot be updated as Subcontracting Inward Order(s) exist against this Subcontracted Sales Order."
-					)
-				)
-			parent.validate_selling_price()
-			parent.validate_for_duplicate_items()
-			parent.validate_warehouse()
-			parent.update_reserved_qty()
-			parent.update_project()
-			parent.update_prevdoc_status("submit")
-			parent.update_delivery_status()
-
-		parent.reload()
-		self._validate_workflow()
-
-		if self.parent_doctype in ("Purchase Order", "Sales Order"):
-			parent.update_blanket_order()
-			parent.update_billing_percentage()
-			parent.set_status()
-
-		parent.validate_uom_is_integer("uom", "qty")
-		parent.validate_uom_is_integer("stock_uom", "stock_qty")
-
-		if self.parent_doctype == "Sales Order" and not parent.is_subcontracted:
-			from erpnext.stock.doctype.stock_reservation_entry.stock_reservation_entry import (
-				cancel_stock_reservation_entries,
-				has_reserved_stock,
-			)
-
-			if has_reserved_stock(parent.doctype, parent.name):
-				cancel_stock_reservation_entries(parent.doctype, parent.name)
-				if parent.per_picked == 0:
-					parent.create_stock_reservation_entries()
-
-	def _check_permissions(self, perm_type: str = "create") -> None:
-		try:
-			self.parent.check_permission(perm_type)
-		except frappe.PermissionError:
-			actions = {"create": "add", "write": "update"}
-			frappe.throw(
-				_("You do not have permissions to {0} items in a {1}.").format(
-					actions[perm_type], self.parent_doctype
-				),
-				title=_("Insufficient Permissions"),
-			)
-
-	def _validate_workflow(self) -> None:
-		workflow = get_workflow_name(self.parent.doctype)
-		if not workflow:
-			return
-
-		workflow_doc = frappe.get_doc("Workflow", workflow)
-		current_state = self.parent.get(workflow_doc.workflow_state_field)
-		roles = frappe.get_roles()
-
-		allowed = any(
-			state.state == current_state and (not state.allow_edit or state.allow_edit in roles)
-			for state in workflow_doc.states
-		)
-
-		if not allowed:
-			frappe.throw(
-				_("You are not allowed to update as per the conditions set in {0} Workflow.").format(
-					get_link_to_form("Workflow", workflow)
-				),
-				title=_("Insufficient Permissions"),
-			)
-
-	def _get_new_child_item(self, item_row) -> "frappe.model.document.Document":
-		child_doctype = self.parent_doctype + " Item"
-		return set_order_defaults(
-			self.parent_doctype,
-			self.parent_doctype_name,
-			child_doctype,
-			self.child_docname,
-			item_row,
-		)
-
-	def _validate_quantity_and_rate(self, child_item, new_data: dict, rate_unchanged: bool | None) -> None:
-		if not flt(new_data.get("qty")) and not self.allow_zero_qty:
-			frappe.throw(
-				_("Row #{0}:Quantity for Item {1} cannot be zero.").format(
-					new_data.get("idx"), frappe.bold(new_data.get("item_code"))
-				),
-				title=_("Invalid Qty"),
-			)
-
-		qty_limits = {
-			"Sales Order": ("delivered_qty", _("Cannot set quantity less than delivered quantity.")),
-			"Purchase Order": ("received_qty", _("Cannot set quantity less than received quantity.")),
-		}
-
-		if self.parent_doctype in qty_limits:
-			qty_field, error_message = qty_limits[self.parent_doctype]
-			if flt(new_data.get("qty")) < flt(child_item.get(qty_field)):
-				frappe.throw(
-					_("Row #{0}:").format(new_data.get("idx")) + error_message,
-					title=_("Invalid Qty"),
-				)
-
-		if self.parent_doctype not in ("Quotation", "Supplier Quotation"):
-			return
-
-		items_map = self._ordered_items if self.parent_doctype == "Quotation" else self._purchased_items
-		if not items_map:
-			return
-
-		qty_to_check = items_map.get(child_item.name)
-		if not qty_to_check:
-			return
-
-		if not rate_unchanged:
-			frappe.throw(
-				_(
-					"Cannot update rate as item {0} is already ordered or purchased against this quotation"
-				).format(frappe.bold(new_data.get("item_code")))
-			)
-
-		if flt(new_data.get("qty")) < qty_to_check:
-			frappe.throw(_("Cannot reduce quantity than ordered or purchased quantity"))
-
-	def _validate_fg_item_for_subcontracting(self, new_data: dict, is_new: bool) -> None:
-		if is_new:
-			if not new_data.get("fg_item"):
-				frappe.throw(
-					_("Finished Good Item is not specified for service item {0}").format(
-						new_data["item_code"]
-					)
-				)
-
-			is_sub_contracted_item, default_bom = frappe.db.get_value(
-				"Item", new_data["fg_item"], ["is_sub_contracted_item", "default_bom"]
-			)
-
-			if not is_sub_contracted_item:
-				frappe.throw(
-					_("Finished Good Item {0} must be a sub-contracted item").format(new_data["fg_item"])
-				)
-			elif not default_bom:
-				frappe.throw(_("Default BOM not found for FG Item {0}").format(new_data["fg_item"]))
-
-		if not new_data.get("fg_item_qty"):
-			frappe.throw(_("Finished Good Item {0} Qty can not be zero").format(new_data["fg_item"]))
-
-
-@frappe.whitelist()
-def update_child_qty_rate(
-	parent_doctype: str, trans_items: str | list, parent_doctype_name: str, child_docname: str = "items"
-) -> None:
-	ChildItemUpdater(parent_doctype, parent_doctype_name, child_docname).update(trans_items)
-
-
-def set_order_defaults(
-	parent_doctype: str,
-	parent_doctype_name: str,
-	child_doctype: str,
-	child_docname: str,
-	trans_item: dict,
-) -> "frappe.model.document.Document":
-	"""Return a new child item populated with item master defaults."""
-	from erpnext.accounts.services.taxes import add_taxes_from_tax_template, set_child_tax_template_and_map
-
-	p_doc = frappe.get_doc(parent_doctype, parent_doctype_name)
-	child_item = frappe.new_doc(child_doctype, parent_doc=p_doc, parentfield=child_docname)
-	item = frappe.get_doc("Item", trans_item.get("item_code"))
-
-	for field in ("item_code", "item_name", "description", "item_group", "weight_per_unit", "weight_uom"):
-		child_item.update({field: item.get(field)})
-
-	date_fieldname = "delivery_date" if child_doctype == "Sales Order Item" else "schedule_date"
-	child_item.update({date_fieldname: trans_item.get(date_fieldname) or p_doc.get(date_fieldname)})
-	child_item.stock_uom = item.stock_uom
-	child_item.uom = trans_item.get("uom") or item.stock_uom
-	child_item.warehouse = get_new_child_item_warehouse(p_doc, item, trans_item, child_doctype)
-	conversion_factor = flt(get_conversion_factor(item.item_code, child_item.uom).get("conversion_factor"))
-	child_item.conversion_factor = flt(trans_item.get("conversion_factor")) or conversion_factor
-	child_item.update(get_bin_details(child_item.item_code, child_item.warehouse, p_doc.get("company")))
-
-	if child_doctype in ("Purchase Order Item", "Supplier Quotation Item"):
-		child_item.base_rate = 1
-		child_item.base_amount = 1
-
-	set_child_tax_template_and_map(item, child_item, p_doc)
-	add_taxes_from_tax_template(child_item, p_doc)
-	return child_item
-
-
-def get_new_child_item_warehouse(p_doc, item, trans_item: dict, child_doctype: str) -> str | None:
-	"""Return the warehouse picked in the Update Items dialog, else the configured default.
-
-	Validates whichever warehouse was resolved, since a submitted parent skips validate().
-	"""
-	warehouse = trans_item.get("warehouse") or get_item_warehouse_(p_doc, item, overwrite_warehouse=True)
-
-	if not warehouse:
-		if is_warehouse_required_for_new_child_item(child_doctype, item, trans_item):
-			frappe.throw(
-				_(
-					"Cannot find a default warehouse for item {0}. Please select one in the Update Items dialog, or set a default in the Item Master or in the Company."
-				).format(frappe.bold(item.item_code))
-			)
-		return None
-
-	validate_warehouse_company(warehouse, p_doc.company)
-	validate_disabled_warehouse(warehouse)
-	is_group_warehouse(warehouse)
-	return warehouse
-
-
-def is_warehouse_required_for_new_child_item(child_doctype: str, item, trans_item: dict) -> bool:
-	"""Sales Order always needs one; buying documents only for stock rows, as in validate_stock_item_warehouse."""
-	if child_doctype == "Sales Order Item":
-		return True
-
-	if child_doctype in ("Purchase Order Item", "Supplier Quotation Item"):
-		return bool(item.is_stock_item and flt(trans_item.get("qty")) and not item.delivered_by_supplier)
-
-	return False
-
-
-def validate_child_on_delete(row, parent, ordered_item=None) -> None:
-	"""Raise if a partially transacted child item is being deleted."""
-	if parent.doctype == "Sales Order":
-		if flt(row.delivered_qty):
-			frappe.throw(
-				_("Row #{0}: Cannot delete item {1} which has already been delivered").format(
-					row.idx, row.item_code
-				)
-			)
-		if flt(row.work_order_qty):
-			frappe.throw(
-				_("Row #{0}: Cannot delete item {1} which has work order assigned to it.").format(
-					row.idx, row.item_code
-				)
-			)
-		if flt(row.ordered_qty):
-			frappe.throw(
-				_(
-					"Row #{0}: Cannot delete item {1} which is already ordered against this Sales Order."
-				).format(row.idx, row.item_code)
-			)
-
-	if parent.doctype == "Purchase Order" and flt(row.received_qty):
-		frappe.throw(
-			_("Row #{0}: Cannot delete item {1} which has already been received").format(
-				row.idx, row.item_code
-			)
-		)
-
-	if parent.doctype in ("Purchase Order", "Sales Order") and flt(row.billed_amt):
-		frappe.throw(
-			_("Row #{0}: Cannot delete item {1} which has already been billed.").format(
-				row.idx, row.item_code
-			)
-		)
-
-	if parent.doctype == "Quotation" and ordered_item and ordered_item.get(row.name):
-		frappe.throw(_("Cannot delete an item which has been ordered"))
-
-
-def update_bin_on_delete(row, doctype: str) -> None:
-	"""Update bin quantities after a child item row is deleted."""
-	from erpnext.stock.stock_balance import (
-		get_indented_qty,
-		get_ordered_qty,
-		get_reserved_qty,
-		update_bin_qty,
-	)
-
-	qty_dict = {}
-
-	if doctype == "Sales Order":
-		qty_dict["reserved_qty"] = get_reserved_qty(row.item_code, row.warehouse)
-	else:
-		if row.material_request_item:
-			qty_dict["indented_qty"] = get_indented_qty(row.item_code, row.warehouse)
-		qty_dict["ordered_qty"] = get_ordered_qty(row.item_code, row.warehouse)
-
-	if row.warehouse:
-		update_bin_qty(row.item_code, row.warehouse, qty_dict)
-
-
-def validate_and_delete_children(parent, data, ordered_item=None) -> bool:
-	"""Delete child rows not present in data; return True if any were removed."""
-	updated_item_names = [d.get("docname") for d in data]
-	deleted_children = [item for item in parent.items if item.name not in updated_item_names]
-
-	for d in deleted_children:
-		validate_child_on_delete(d, parent, ordered_item)
-		d.flags.ignore_permissions = True
-		d.cancel()
-		d.delete()
-
-	if parent.doctype == "Purchase Order":
-		parent.update_ordered_qty_in_so_for_removed_items(deleted_children)
-
-	if parent.doctype not in ("Quotation", "Supplier Quotation"):
-		parent.update_prevdoc_status()
-		for d in deleted_children:
-			update_bin_on_delete(d, parent.doctype)
-
-	return bool(deleted_children)
-
-
-def get_allow_zero_qty(parent_doctype: str) -> bool:
-	if parent_doctype == "Sales Order":
-		return frappe.db.get_single_value("Selling Settings", "allow_zero_qty_in_sales_order") or False
-	if parent_doctype == "Purchase Order":
-		return frappe.db.get_single_value("Buying Settings", "allow_zero_qty_in_purchase_order") or False
-	return False
-
-
-def get_child_item_change_state(parent_doctype: str, child_item, new_data) -> frappe._dict:
-	prev_rate, new_rate = flt(child_item.get("rate")), flt(new_data.get("rate"))
-	prev_qty, new_qty = flt(child_item.get("qty")), flt(new_data.get("qty"))
-	prev_fg_qty, new_fg_qty = flt(child_item.get("fg_item_qty")), flt(new_data.get("fg_item_qty"))
-	prev_con_fac = flt(child_item.get("conversion_factor"))
-	new_con_fac = flt(new_data.get("conversion_factor"))
-
-	if parent_doctype == "Sales Order":
-		prev_date, new_date = child_item.get("delivery_date"), new_data.get("delivery_date")
-	elif parent_doctype == "Purchase Order":
-		prev_date, new_date = child_item.get("schedule_date"), new_data.get("schedule_date")
-	else:
-		prev_date, new_date = None, None
-
-	if parent_doctype in ("Quotation", "Supplier Quotation"):
-		date_unchanged = False
-	else:
-		prev_date = getdate(prev_date) if prev_date else None
-		new_date = getdate(new_date) if new_date else None
-		date_unchanged = prev_date == new_date
-
-	return frappe._dict(
-		rate_unchanged=prev_rate == new_rate,
-		qty_unchanged=prev_qty == new_qty,
-		fg_qty_unchanged=prev_fg_qty == new_fg_qty,
-		uom_unchanged=child_item.get("uom") == new_data.get("uom"),
-		conversion_factor_unchanged=prev_con_fac == new_con_fac,
-		date_unchanged=date_unchanged,
-		description_unchanged=child_item.get("description") == new_data.get("description"),
-	)
-
-
-def is_child_item_unchanged(change_state: frappe._dict) -> bool:
-	return (
-		change_state.rate_unchanged
-		and change_state.qty_unchanged
-		and change_state.fg_qty_unchanged
-		and change_state.conversion_factor_unchanged
-		and change_state.uom_unchanged
-		and change_state.date_unchanged
-		and change_state.description_unchanged
-	)
-
-
-def update_child_item_rate_and_discount(
-	parent_doctype: str,
-	child_item,
-	new_data,
-	allow_zero_qty: bool,
-	rate_unchanged: bool | None = None,
-) -> None:
-	rate_precision = child_item.precision("rate") or 2
-	qty_precision = child_item.precision("qty") or 2
-
-	if rate_unchanged is None:
-		rate_unchanged = flt(child_item.get("rate")) == flt(new_data.get("rate"))
-
-	if not rate_unchanged and not child_item.get("qty") and allow_zero_qty:
-		frappe.throw(_("Rate of '{0}' items cannot be changed").format(frappe.bold(_("Unit Price"))))
-
-	row_rate = flt(new_data.get("rate"), rate_precision)
-
-	if parent_doctype in ("Purchase Order", "Sales Order"):
-		amount_below_billed_amt = flt(child_item.billed_amt, rate_precision) > flt(
-			row_rate * flt(new_data.get("qty"), qty_precision), rate_precision
-		)
-		if amount_below_billed_amt and row_rate > 0.0:
-			frappe.throw(
-				_(
-					"Row #{0}: Cannot set Rate if the billed amount is greater than the amount for Item {1}."
-				).format(child_item.idx, child_item.item_code)
-			)
-
-	child_item.rate = row_rate
-
-	if parent_doctype not in ("Sales Order", "Purchase Order") or not flt(child_item.price_list_rate):
-		return
-
-	if flt(child_item.rate) > flt(child_item.price_list_rate):
-		child_item.discount_percentage = 0
-		child_item.discount_amount = 0
-		child_item.margin_type = "Amount"
-		child_item.margin_rate_or_amount = flt(
-			child_item.rate - child_item.price_list_rate,
-			child_item.precision("margin_rate_or_amount"),
-		)
-		child_item.rate_with_margin = child_item.rate
-	else:
-		child_item.margin_type = ""
-		child_item.margin_rate_or_amount = 0
-		child_item.rate_with_margin = child_item.price_list_rate
-		child_item.discount_percentage = 0
-		child_item.discount_amount = flt(child_item.rate_with_margin) - flt(child_item.rate)
-
-
-def update_child_item_uom_and_weight(child_item, new_data) -> None:
-	conv_fac_precision = child_item.precision("conversion_factor") or 2
-
-	if new_data.get("conversion_factor"):
-		if child_item.stock_uom == child_item.uom:
-			child_item.conversion_factor = 1
-		else:
-			child_item.conversion_factor = flt(new_data.get("conversion_factor"), conv_fac_precision)
-
-	if new_data.get("uom"):
-		child_item.uom = new_data.get("uom")
-		conversion_factor = flt(
-			get_conversion_factor(child_item.item_code, child_item.uom).get("conversion_factor")
-		)
-		child_item.conversion_factor = (
-			flt(new_data.get("conversion_factor"), conv_fac_precision) or conversion_factor
-		)
-
-	if child_item.get("weight_per_unit"):
-		child_item.total_weight = flt(
-			child_item.weight_per_unit * child_item.qty * child_item.conversion_factor,
-			child_item.precision("total_weight"),
-		)
-
-
-def check_if_child_table_updated(
-	child_table_before_update, child_table_after_update, fields_to_check
-) -> bool:
-	"""Return True if any accounting-relevant field changed in a child table."""
-	fields_to_check = list(fields_to_check) + get_accounting_dimensions() + ["cost_center", "project"]
-
-	for index, item in enumerate(child_table_before_update):
-		for field in fields_to_check:
-			if child_table_after_update[index].get(field) != item.get(field):
-				return True
-
-	return False
diff --git a/erpnext/controllers/accounts_controller.py b/erpnext/controllers/accounts_controller.py
index 7f2afecaf9f..6ee13e7cb1f 100644
--- a/erpnext/controllers/accounts_controller.py
+++ b/erpnext/controllers/accounts_controller.py
@@ -75,6 +75,11 @@ from erpnext.stock.get_item_details import (
 	get_item_tax_map,
 	get_item_warehouse,
 )
+from erpnext.stock.utils import (
+	is_group_warehouse,
+	validate_disabled_warehouse,
+	validate_warehouse_company,
+)
 from erpnext.utilities.regional import temporary_flag
 from erpnext.utilities.transaction_base import TransactionBase
 
@@ -3722,7 +3727,7 @@ def set_order_defaults(parent_doctype, parent_doctype_name, child_doctype, child
 	child_item.update({date_fieldname: trans_item.get(date_fieldname) or p_doc.get(date_fieldname)})
 	child_item.stock_uom = item.stock_uom
 	child_item.uom = trans_item.get("uom") or item.stock_uom
-	child_item.warehouse = get_item_warehouse(item, p_doc, overwrite_warehouse=True)
+	child_item.warehouse = get_new_child_item_warehouse(p_doc, item, trans_item, child_doctype)
 	conversion_factor = flt(get_conversion_factor(item.item_code, child_item.uom).get("conversion_factor"))
 	child_item.conversion_factor = flt(trans_item.get("conversion_factor")) or conversion_factor
 	child_item.update(get_bin_details(child_item.item_code, child_item.warehouse, p_doc.get("company")))
@@ -3731,20 +3736,45 @@ def set_order_defaults(parent_doctype, parent_doctype_name, child_doctype, child
 		# Initialized value will update in parent validation
 		child_item.base_rate = 1
 		child_item.base_amount = 1
-	if child_doctype == "Sales Order Item":
-		child_item.warehouse = get_item_warehouse(item, p_doc, overwrite_warehouse=True)
-		if not child_item.warehouse:
-			frappe.throw(
-				_(
-					"Cannot find a default warehouse for item {0}. Please set one in the Item Master or in Stock Settings."
-				).format(frappe.bold(item.item_code))
-			)
 
 	set_child_tax_template_and_map(item, child_item, p_doc)
 	add_taxes_from_tax_template(child_item, p_doc)
 	return child_item
 
 
+def get_new_child_item_warehouse(p_doc, item, trans_item: dict, child_doctype: str) -> str | None:
+	"""Return the warehouse picked in the Update Items dialog, else the configured default.
+
+	Validates whichever warehouse was resolved, since a submitted parent skips validate().
+	"""
+	warehouse = trans_item.get("warehouse") or get_item_warehouse(item, p_doc, overwrite_warehouse=True)
+
+	if not warehouse:
+		if is_warehouse_required_for_new_child_item(child_doctype, item, trans_item):
+			frappe.throw(
+				_(
+					"Cannot find a default warehouse for item {0}. Please select one in the Update Items dialog, or set a default in the Item Master or in the Company."
+				).format(frappe.bold(item.item_code))
+			)
+		return None
+
+	validate_warehouse_company(warehouse, p_doc.company)
+	validate_disabled_warehouse(warehouse)
+	is_group_warehouse(warehouse)
+	return warehouse
+
+
+def is_warehouse_required_for_new_child_item(child_doctype: str, item, trans_item: dict) -> bool:
+	"""Sales Order always needs one; buying documents only for stock rows, as in validate_stock_item_warehouse."""
+	if child_doctype == "Sales Order Item":
+		return True
+
+	if child_doctype in ("Purchase Order Item", "Supplier Quotation Item"):
+		return bool(item.is_stock_item and flt(trans_item.get("qty")) and not item.delivered_by_supplier)
+
+	return False
+
+
 def validate_child_on_delete(row, parent, ordered_item=None):
 	"""Check if partially transacted item (row) is being deleted."""
 	if parent.doctype == "Sales Order":
diff --git a/erpnext/public/js/utils.js b/erpnext/public/js/utils.js
index 47143d6cad1..2f66c0720d8 100755
--- a/erpnext/public/js/utils.js
+++ b/erpnext/public/js/utils.js
@@ -728,21 +728,14 @@ erpnext.utils.update_child_items = function (opts) {
 					},
 					callback: function (r) {
 						if (r.message) {
-<<<<<<< HEAD
-							const { qty, price_list_rate: rate, uom, conversion_factor, bom_no } = r.message;
-
-=======
 							const {
 								qty,
 								price_list_rate: rate,
 								uom,
 								conversion_factor,
-								item_name,
 								bom_no,
-								description,
 								warehouse,
 							} = r.message;
->>>>>>> 55fe269046 (fix: allow selecting a warehouse for new items in the update items dialog (#57876))
 							const row = dialog.fields_dict.trans_items.df.data.find(
 								(doc) => doc.idx == me.doc.idx
 							);
@@ -753,11 +746,7 @@ erpnext.utils.update_child_items = function (opts) {
 									qty: me.doc.qty || qty,
 									rate: me.doc.rate || rate,
 									bom_no: bom_no,
-<<<<<<< HEAD
-=======
-									description: me.doc.description || description,
 									warehouse: me.doc.docname ? me.doc.warehouse : warehouse,
->>>>>>> 55fe269046 (fix: allow selecting a warehouse for new items in the update items dialog (#57876))
 								});
 								dialog.fields_dict.trans_items.grid.refresh();
 							}
@@ -831,13 +820,6 @@ erpnext.utils.update_child_items = function (opts) {
 		});
 	}
 
-<<<<<<< HEAD
-	if (
-		frm.doc.doctype == "Purchase Order" &&
-		frm.doc.is_subcontracted &&
-		!frm.doc.is_old_subcontracting_flow
-	) {
-=======
 	const warehouse_df = child_meta.fields.find((f) => f.fieldname == "warehouse");
 	if (warehouse_df) {
 		fields.splice(3, 0, {
@@ -861,8 +843,11 @@ erpnext.utils.update_child_items = function (opts) {
 		});
 	}
 
-	if (["Purchase Order", "Sales Order"].includes(frm.doc.doctype) && frm.doc.is_subcontracted) {
->>>>>>> 55fe269046 (fix: allow selecting a warehouse for new items in the update items dialog (#57876))
+	if (
+		frm.doc.doctype == "Purchase Order" &&
+		frm.doc.is_subcontracted &&
+		!frm.doc.is_old_subcontracting_flow
+	) {
 		fields.push(
 			{
 				fieldtype: "Link",
diff --git a/erpnext/selling/doctype/sales_order/test_sales_order.py b/erpnext/selling/doctype/sales_order/test_sales_order.py
index 6e38ae6e116..ccead71f71e 100644
--- a/erpnext/selling/doctype/sales_order/test_sales_order.py
+++ b/erpnext/selling/doctype/sales_order/test_sales_order.py
@@ -33,11 +33,7 @@ from erpnext.selling.doctype.sales_order.sales_order import (
 from erpnext.stock.doctype.item.test_item import make_item
 from erpnext.stock.doctype.stock_entry.stock_entry_utils import make_stock_entry
 from erpnext.stock.get_item_details import get_bin_details
-<<<<<<< HEAD
-=======
 from erpnext.stock.utils import InvalidWarehouseCompany
-from erpnext.tests.utils import ERPNextTestSuite
->>>>>>> 55fe269046 (fix: allow selecting a warehouse for new items in the update items dialog (#57876))
 
 
 class TestSalesOrder(AccountsTestMixin, FrappeTestCase):