diff --git a/purchase_invoice_separate_valuation/README.md b/purchase_invoice_separate_valuation/README.md
new file mode 100644
index 0000000..e69de29
diff --git a/purchase_invoice_separate_valuation/__init__.py b/purchase_invoice_separate_valuation/__init__.py
new file mode 100644
index 0000000..6ed2c21
--- /dev/null
+++ b/purchase_invoice_separate_valuation/__init__.py
@@ -0,0 +1,2 @@
+from . import models
+from . import wizards
\ No newline at end of file
diff --git a/purchase_invoice_separate_valuation/__manifest__.py b/purchase_invoice_separate_valuation/__manifest__.py
new file mode 100644
index 0000000..13f3510
--- /dev/null
+++ b/purchase_invoice_separate_valuation/__manifest__.py
@@ -0,0 +1,24 @@
+{
+    'name': 'Purchase Invoice Separate Valuation',
+    'version': '16.0.2.0.0',
+    'category': 'Purchase',
+    'summary': 'Separate purchase invoicing from stock valuation',
+    'depends': [
+        'purchase',
+        'purchase_stock',
+        'stock_account',
+        'account',
+        'stock_landed_costs',
+    ],
+    'data': [
+        'security/ir.model.access.csv',
+        'wizards/purchase_make_invoice_advance_views.xml',
+        'views/account_move_views.xml',
+        'views/purchase_views.xml',
+        'views/res_config_settings_views.xml',
+    ],
+    'installable': True,
+    'auto_install': False,
+    'application': False,
+    'license': 'AGPL-3',
+}
diff --git a/purchase_invoice_separate_valuation/models/__init__.py b/purchase_invoice_separate_valuation/models/__init__.py
new file mode 100644
index 0000000..214393f
--- /dev/null
+++ b/purchase_invoice_separate_valuation/models/__init__.py
@@ -0,0 +1,7 @@
+from . import res_company
+from . import res_config_settings
+from . import purchase_order_line
+from . import purchase_order
+from . import account_move
+from . import account_move_line
+from . import stock_move
diff --git a/purchase_invoice_separate_valuation/models/account_move.py b/purchase_invoice_separate_valuation/models/account_move.py
new file mode 100644
index 0000000..00185d5
--- /dev/null
+++ b/purchase_invoice_separate_valuation/models/account_move.py
@@ -0,0 +1,266 @@
+# -*- coding: utf-8 -*-
+from odoo import api, fields, models, _
+from odoo.exceptions import UserError
+
+_VENDOR_BILL_TYPES = frozenset({'in_invoice', 'in_refund', 'in_receipt'})
+
+
+class AccountMove(models.Model):
+    _inherit = 'account.move'
+
+    is_final_invoice = fields.Boolean(
+        string='Final Invoice',
+        default=False,
+        copy=False,
+    )
+    price_adjustment_move_id = fields.Many2one(
+        'account.move',
+        string='Price Adjustment Entry',
+        compute='_compute_price_adjustment_move_id',
+        readonly=True,
+    )
+    po_has_other_final_invoice = fields.Boolean(
+        string='PO Has Other Final Invoice',
+        compute='_compute_po_has_other_final_invoice',
+    )
+    po_use_separate_valuation = fields.Boolean(
+        string='PO Uses Separate Valuation',
+        compute='_compute_po_use_separate_valuation',
+        help='True when a linked purchase order uses separate valuation mode.',
+    )
+
+    @api.depends(
+        'purchase_id',
+        'purchase_id.use_separate_valuation',
+        'invoice_line_ids.purchase_line_id.order_id',
+        'invoice_line_ids.purchase_line_id.order_id.use_separate_valuation',
+    )
+    def _compute_po_use_separate_valuation(self):
+        for move in self:
+            move.po_use_separate_valuation = bool(
+                move._get_linked_purchase_orders().filtered('use_separate_valuation')
+            )
+
+    @api.depends(
+        'purchase_id',
+        'invoice_line_ids.purchase_line_id.order_id',
+        'purchase_id.final_invoice_move_id',
+        'purchase_id.final_invoice_move_id.state',
+        'invoice_line_ids.purchase_line_id.order_id.final_invoice_move_id',
+        'invoice_line_ids.purchase_line_id.order_id.final_invoice_move_id.state',
+        'invoice_line_ids.purchase_line_id.order_id.order_line.invoice_lines.move_id.is_final_invoice',
+        'invoice_line_ids.purchase_line_id.order_id.order_line.invoice_lines.move_id.state',
+    )
+    def _compute_po_has_other_final_invoice(self):
+        for move in self:
+            move.po_has_other_final_invoice = any(
+                purchase._get_final_invoice() and purchase._get_final_invoice() != move
+                for purchase in move._get_linked_purchase_orders().filtered('use_separate_valuation')
+            )
+
+    @api.depends(
+        'purchase_id',
+        'invoice_line_ids.purchase_line_id.order_id',
+        'purchase_id.price_adjustment_move_id',
+        'purchase_id.final_invoice_move_id',
+        'invoice_line_ids.purchase_line_id.order_id.price_adjustment_move_id',
+        'invoice_line_ids.purchase_line_id.order_id.final_invoice_move_id',
+    )
+    def _compute_price_adjustment_move_id(self):
+        for move in self:
+            adjustment_move = self.env['account.move']
+            for purchase in move._get_linked_purchase_orders().filtered('use_separate_valuation'):
+                if purchase._get_final_invoice() == move:
+                    adjustment_move = purchase.price_adjustment_move_id
+                    break
+            move.price_adjustment_move_id = adjustment_move[:1]
+
+    def _post(self, soft=True):
+        to_post = self.filtered(lambda m: m.state == 'draft') if soft else self
+
+        for bill in to_post.filtered(lambda m: m.move_type in _VENDOR_BILL_TYPES):
+            purchases = bill._get_separate_valuation_purchase_orders()
+            if bill.is_final_invoice:
+                purchase = bill._get_final_invoice_purchase_order()
+                purchase._check_can_assign_final_invoice(bill, require_posted=False)
+                purchase._check_price_adjustment_account_configured()
+            elif bill.move_type != 'in_refund':
+                for purchase in purchases:
+                    purchase._check_no_bill_after_final_invoice(bill)
+
+        result = super()._post(soft)
+
+        purchases_to_sync = self.env['purchase.order']
+        already_synced = self.env['purchase.order']
+        for bill in result.filtered(lambda m: m.move_type in _VENDOR_BILL_TYPES):
+            purchases_to_sync |= bill._get_separate_valuation_purchase_orders()
+
+        for bill in result.filtered(
+            lambda m: m.is_final_invoice and m.move_type in _VENDOR_BILL_TYPES
+        ):
+            purchase = bill._get_final_invoice_purchase_order(raise_if_missing=False)
+            if purchase:
+                purchase._set_final_invoice(bill)
+                already_synced |= purchase
+
+        for purchase in purchases_to_sync - already_synced:
+            purchase._sync_price_adjustment_entry()
+
+        return result
+
+    def write(self, vals):
+        track_final_flag = 'is_final_invoice' in vals
+        track_purchase_link = 'purchase_id' in vals
+
+        purchases_before = {}
+        if track_final_flag or track_purchase_link:
+            for move in self.filtered(lambda m: m.move_type in _VENDOR_BILL_TYPES):
+                purchases_before[move.id] = move._get_linked_purchase_orders().filtered(
+                    'use_separate_valuation'
+                )
+
+        res = super().write(vals)
+        if self.env.context.get('skip_purchase_final_invoice_sync'):
+            return res
+
+        if track_final_flag:
+            for move in self.filtered(
+                lambda m: m.state == 'posted' and m.move_type in _VENDOR_BILL_TYPES
+            ):
+                if move.is_final_invoice:
+                    purchase = move._get_final_invoice_purchase_order()
+                    purchase._set_final_invoice(move)
+                    continue
+
+                for old_purchase in purchases_before.get(move.id, self.env['purchase.order']):
+                    if old_purchase._get_final_invoice() == move or old_purchase.final_invoice_move_id == move:
+                        old_purchase._clear_final_invoice(invoice=move)
+        elif track_purchase_link:
+            purchases_to_sync = self.env['purchase.order']
+            for move in self.filtered(
+                lambda m: m.state == 'posted' and m.move_type in _VENDOR_BILL_TYPES
+            ):
+                purchases_to_sync |= purchases_before.get(move.id, self.env['purchase.order'])
+                purchases_to_sync |= move._get_separate_valuation_purchase_orders()
+            for purchase in purchases_to_sync.filtered('use_separate_valuation'):
+                purchase._sync_price_adjustment_entry()
+
+        return res
+
+    def button_draft(self):
+        vendor_bills = self.filtered(lambda m: m.move_type in _VENDOR_BILL_TYPES)
+        purchases_before = {
+            move.id: move._get_separate_valuation_purchase_orders()
+            for move in vendor_bills
+        }
+        final_purchases_before = {
+            move.id: purchases_before[move.id].filtered(lambda po, move=move: po._get_final_invoice() == move)
+            for move in vendor_bills
+        }
+
+        result = super().button_draft()
+        if self.env.context.get('skip_purchase_final_invoice_sync'):
+            return result
+
+        to_sync = self.env['purchase.order']
+        cleared = self.env['purchase.order']
+        for move in vendor_bills:
+            to_sync |= purchases_before[move.id]
+            to_sync |= move._get_separate_valuation_purchase_orders()
+            for purchase in final_purchases_before[move.id]:
+                purchase._clear_final_invoice(invoice=move)
+                cleared |= purchase
+
+        for purchase in (to_sync - cleared).filtered('use_separate_valuation'):
+            purchase._sync_price_adjustment_entry()
+        return result
+
+    def button_cancel(self):
+        vendor_bills = self.filtered(lambda m: m.move_type in _VENDOR_BILL_TYPES)
+        purchases_before = {
+            move.id: move._get_separate_valuation_purchase_orders()
+            for move in vendor_bills
+        }
+        final_purchases_before = {
+            move.id: purchases_before[move.id].filtered(lambda po, move=move: po._get_final_invoice() == move)
+            for move in vendor_bills
+        }
+
+        result = super().button_cancel()
+        if self.env.context.get('skip_purchase_final_invoice_sync'):
+            return result
+
+        to_sync = self.env['purchase.order']
+        cleared = self.env['purchase.order']
+        for move in vendor_bills:
+            to_sync |= purchases_before[move.id]
+            to_sync |= move._get_separate_valuation_purchase_orders()
+            for purchase in final_purchases_before[move.id]:
+                purchase._clear_final_invoice(invoice=move)
+                cleared |= purchase
+
+        for purchase in (to_sync - cleared).filtered('use_separate_valuation'):
+            purchase._sync_price_adjustment_entry()
+        return result
+
+    # ------------------------------------------------------------------
+    # Helpers
+    # ------------------------------------------------------------------
+
+    def _get_linked_purchase_orders(self):
+        self.ensure_one()
+        return self.purchase_id | self.invoice_line_ids.mapped('purchase_line_id.order_id')
+
+    def _get_separate_valuation_purchase_orders(self):
+        self.ensure_one()
+        return self._get_linked_purchase_orders().filtered('use_separate_valuation')
+
+    def _get_final_invoice_purchase_order(self, raise_if_missing=True):
+        self.ensure_one()
+        purchases = self._get_separate_valuation_purchase_orders()
+        if not purchases:
+            if raise_if_missing:
+                raise UserError(_(
+                    'The Final Invoice flag can only be used on vendor bills linked to a '
+                    'purchase order that uses Separate Valuation Mode.'
+                ))
+            return self.env['purchase.order']
+        if len(purchases) > 1:
+            raise UserError(_(
+                'Final Invoice is only supported on vendor bills linked to a single '
+                'Separate Valuation purchase order.'
+            ))
+        return purchases
+
+    def _sync_price_adjustment_entry(self):
+        self.ensure_one()
+        purchase = self._get_final_invoice_purchase_order(raise_if_missing=False)
+        if purchase:
+            purchase._sync_price_adjustment_entry()
+
+    # ------------------------------------------------------------------
+    # Admin actions (Purchase Manager only)
+    # ------------------------------------------------------------------
+
+    def _check_purchase_manager(self):
+        if not self.env.user.has_group('purchase.group_purchase_manager'):
+            raise UserError(_('Only Purchase Managers can change the Final Invoice status.'))
+
+    def action_mark_as_final_invoice(self):
+        self.ensure_one()
+        self._check_purchase_manager()
+        purchase = self._get_final_invoice_purchase_order()
+        purchase._set_final_invoice(self)
+
+    def action_unmark_as_final_invoice(self):
+        self.ensure_one()
+        self._check_purchase_manager()
+        if self.state != 'posted':
+            raise UserError(_('Only posted invoices can be modified.'))
+        purchase = self._get_final_invoice_purchase_order(raise_if_missing=False)
+        if purchase and purchase._get_final_invoice() == self:
+            purchase._clear_final_invoice(invoice=self)
+        elif self.is_final_invoice:
+            self.with_context(skip_purchase_final_invoice_sync=True).write({
+                'is_final_invoice': False,
+            })
diff --git a/purchase_invoice_separate_valuation/models/account_move_line.py b/purchase_invoice_separate_valuation/models/account_move_line.py
new file mode 100644
index 0000000..3e78c86
--- /dev/null
+++ b/purchase_invoice_separate_valuation/models/account_move_line.py
@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+from odoo import models
+
+_VENDOR_BILL_TYPES = frozenset({'in_invoice', 'in_refund', 'in_receipt'})
+
+
+class AccountMoveLine(models.Model):
+    _inherit = 'account.move.line'
+
+    def _apply_price_difference(self):
+        """Block price-difference SVL creation for separate-valuation vendor bills."""
+        def _is_separate(line):
+            if line.move_id.move_type not in _VENDOR_BILL_TYPES:
+                return False
+            purchase = line.purchase_line_id.order_id or line.move_id.purchase_id
+            return bool(purchase and purchase.use_separate_valuation)
+
+        separate = self.filtered(_is_separate)
+        non_separate = self - separate
+        if not non_separate:
+            return self.env['stock.valuation.layer'], self.env['account.move.line']
+        return super(AccountMoveLine, non_separate)._apply_price_difference()
diff --git a/purchase_invoice_separate_valuation/models/purchase_order.py b/purchase_invoice_separate_valuation/models/purchase_order.py
new file mode 100644
index 0000000..196a608
--- /dev/null
+++ b/purchase_invoice_separate_valuation/models/purchase_order.py
@@ -0,0 +1,350 @@
+# -*- coding: utf-8 -*-
+from odoo import api, fields, models, _
+from odoo.exceptions import UserError
+from odoo.tools import float_is_zero
+
+_VENDOR_BILL_TYPES = frozenset({'in_invoice', 'in_refund', 'in_receipt'})
+_FINAL_INVOICE_TYPES = frozenset({'in_invoice', 'in_receipt'})
+
+
+class PurchaseOrder(models.Model):
+    _inherit = 'purchase.order'
+
+    use_separate_valuation = fields.Boolean(
+        string='Separate Valuation Mode',
+        default=False,
+        copy=False,
+        readonly=True,
+        help='Set automatically when invoices are created via "Create Invoice (Advanced)". '
+             'When active, the standard "Create Invoice" button is blocked and invoicing '
+             'is managed separately from stock valuation.',
+    )
+    price_diff_reason = fields.Text(
+        string='Price Difference Note',
+        help='Reason for any difference between the receipt value and the invoiced amount.',
+    )
+    amount_invoiced = fields.Monetary(
+        string='Invoiced Amount',
+        compute='_compute_amount_invoiced',
+        store=True,
+        currency_field='currency_id',
+    )
+    amount_to_invoice = fields.Monetary(
+        string='Amount to Invoice',
+        compute='_compute_amount_invoiced',
+        store=True,
+        currency_field='currency_id',
+    )
+    has_final_invoice = fields.Boolean(
+        string='Has Final Invoice',
+        compute='_compute_has_final_invoice',
+    )
+    final_invoice_move_id = fields.Many2one(
+        'account.move',
+        string='Final Invoice',
+        readonly=True,
+        copy=False,
+        ondelete='set null',
+    )
+    price_adjustment_move_id = fields.Many2one(
+        'account.move',
+        string='Price Adjustment Entry',
+        readonly=True,
+        copy=False,
+        ondelete='set null',
+    )
+
+    @api.depends(
+        'final_invoice_move_id',
+        'final_invoice_move_id.state',
+        'final_invoice_move_id.move_type',
+        'order_line.invoice_lines.move_id.is_final_invoice',
+        'order_line.invoice_lines.move_id.state',
+        'order_line.invoice_lines.move_id.move_type',
+    )
+    def _compute_has_final_invoice(self):
+        for order in self:
+            order.has_final_invoice = bool(order._get_final_invoice())
+
+    @api.depends('order_line.amount_invoiced', 'amount_untaxed', 'currency_id')
+    def _compute_amount_invoiced(self):
+        for order in self:
+            total = sum(order.order_line.mapped('amount_invoiced'))
+            order.amount_invoiced = total
+            order.amount_to_invoice = order.amount_untaxed - total
+
+    def action_create_invoice(self):
+        """Block standard invoice creation for orders using separate valuation mode."""
+        blocked = self.filtered('use_separate_valuation')
+        if blocked:
+            names = ', '.join(blocked.mapped('name'))
+            raise UserError(_(
+                'The following purchase order(s) use Separate Valuation Mode:\n%s\n\n'
+                'Please use the "Create Invoice (Advanced)" button instead.'
+            ) % names)
+        return super().action_create_invoice()
+
+    # ------------------------------------------------------------------
+    # Separate valuation helpers
+    # ------------------------------------------------------------------
+
+    def _get_vendor_bills(self):
+        self.ensure_one()
+        return self.order_line.mapped('invoice_lines.move_id').filtered(
+            lambda m: m.move_type in _VENDOR_BILL_TYPES
+        )
+
+    def _get_final_invoice(self):
+        self.ensure_one()
+        final_invoice = self.final_invoice_move_id
+        if final_invoice and final_invoice.state == 'posted' and final_invoice.move_type in _FINAL_INVOICE_TYPES:
+            return final_invoice
+        legacy_final = self._get_vendor_bills().filtered(
+            lambda m: m.is_final_invoice
+            and m.state == 'posted'
+            and m.move_type in _FINAL_INVOICE_TYPES
+        )
+        return legacy_final[:1]
+
+    def _check_can_create_advanced_invoice(self, is_final=False):
+        self.ensure_one()
+        if self.state not in ('purchase', 'done'):
+            raise UserError(_(
+                'You can only create invoices from confirmed purchase orders.'
+            ))
+
+        existing_bills = self._get_vendor_bills().filtered(lambda m: m.state != 'cancel')
+        if not self.use_separate_valuation and existing_bills:
+            raise UserError(_(
+                'Purchase order %s already has vendor bills.\n'
+                'Separate Valuation Mode must be started before any vendor bill is created.'
+            ) % self.name)
+
+        existing_final = self._get_final_invoice()
+        if existing_final:
+            raise UserError(_(
+                'Purchase order %s already has a final invoice (%s).\n'
+                'Clear the Final Invoice status before creating another bill.'
+            ) % (self.name, existing_final.display_name or existing_final.name))
+
+    def _check_no_bill_after_final_invoice(self, bill=None):
+        self.ensure_one()
+        if bill and bill.move_type == 'in_refund':
+            return
+        if not self.use_separate_valuation:
+            return
+        existing_final = self._get_final_invoice()
+        if existing_final and existing_final != bill:
+            raise UserError(_(
+                'Purchase order %s already has a final invoice (%s).\n'
+                'No additional vendor bills can be posted for this order.'
+            ) % (self.name, existing_final.display_name or existing_final.name))
+
+    def _check_can_assign_final_invoice(self, invoice, require_posted=True):
+        self.ensure_one()
+        if require_posted and invoice.state != 'posted':
+            raise UserError(_('Only posted invoices can be marked as Final Invoice.'))
+        if invoice.move_type not in _FINAL_INVOICE_TYPES:
+            raise UserError(_('Only vendor bills can be marked as Final Invoice.'))
+        if not self.use_separate_valuation:
+            raise UserError(_(
+                'The Final Invoice flag can only be set on vendor bills linked to a purchase '
+                'order that uses Separate Valuation Mode.'
+            ))
+        if invoice not in self._get_vendor_bills():
+            raise UserError(_(
+                'Invoice %s is not linked to purchase order %s.'
+            ) % (invoice.display_name or invoice.name, self.name))
+        existing_final = self._get_final_invoice()
+        if existing_final and existing_final != invoice:
+            raise UserError(_(
+                'Purchase order %s already has a final invoice (%s).\n'
+                'Please remove the existing final invoice status first.'
+            ) % (self.name, existing_final.display_name or existing_final.name))
+
+    def _set_final_invoice(self, invoice):
+        self.ensure_one()
+        self._check_can_assign_final_invoice(invoice)
+
+        current_final = self._get_final_invoice()
+        if current_final and current_final != invoice and current_final.is_final_invoice:
+            current_final.with_context(skip_purchase_final_invoice_sync=True).write({
+                'is_final_invoice': False,
+            })
+
+        if self.final_invoice_move_id != invoice:
+            self.write({'final_invoice_move_id': invoice.id})
+        if not invoice.is_final_invoice:
+            invoice.with_context(skip_purchase_final_invoice_sync=True).write({
+                'is_final_invoice': True,
+            })
+
+        self._sync_price_adjustment_entry()
+
+    def _clear_final_invoice(self, invoice=None):
+        self.ensure_one()
+        current_final = self._get_final_invoice()
+        if invoice and current_final and current_final != invoice:
+            raise UserError(_(
+                'Invoice %s is not the current Final Invoice for purchase order %s.'
+            ) % (invoice.display_name or invoice.name, self.name))
+
+        invoice_to_clear = current_final or invoice
+        if self.final_invoice_move_id:
+            self.write({'final_invoice_move_id': False})
+        if invoice_to_clear and invoice_to_clear.is_final_invoice:
+            invoice_to_clear.with_context(skip_purchase_final_invoice_sync=True).write({
+                'is_final_invoice': False,
+            })
+
+        self._sync_price_adjustment_entry()
+
+    def _get_purchase_stock_input_account_ids(self):
+        self.ensure_one()
+        account_ids = set()
+        for line in self.order_line.filtered('product_id'):
+            account = line.product_id.product_tmpl_id._get_product_accounts().get('stock_input')
+            if account:
+                account_ids.add(account.id)
+        return account_ids
+
+    def _check_price_adjustment_account_configured(self, stock_input_account_ids=None):
+        self.ensure_one()
+        account_ids = stock_input_account_ids
+        if account_ids is None:
+            account_ids = self._get_purchase_stock_input_account_ids()
+        if account_ids and not self.company_id.purchase_price_adjustment_account_id:
+            final_invoice = self._get_final_invoice()
+            raise UserError(_(
+                'Please configure "Purchase Price Adjustment Account" in Accounting settings '
+                'before posting Final Invoice %s.'
+            ) % (final_invoice.display_name or final_invoice.name or self.name))
+
+    def _grni_line_vals(self, invoice, account_id, debit=0.0, credit=0.0):
+        return {
+            'name': _('GRNI adjustment (Final Invoice %s)') % (invoice.name or invoice.display_name),
+            'account_id': account_id,
+            'debit': debit,
+            'credit': credit,
+            'partner_id': invoice.partner_id.id,
+        }
+
+    def _remove_price_adjustment_entry(self):
+        self.ensure_one()
+        adj = self.price_adjustment_move_id
+        if not adj:
+            return
+        try:
+            if adj.state == 'posted':
+                adj.button_draft()
+            adj.unlink()
+        except Exception as err:
+            raise UserError(_(
+                'Could not remove the GRNI adjustment entry %s.\n'
+                'Please unreconcile or manually reverse it first.\n\nDetail: %s'
+            ) % (adj.name, str(err))) from err
+        self.write({'price_adjustment_move_id': False})
+
+    def _sync_price_adjustment_entry(self):
+        for order in self:
+            order._sync_price_adjustment_entry_one()
+
+    def _sync_price_adjustment_entry_one(self):
+        self.ensure_one()
+
+        final_invoice = self._get_final_invoice()
+        if final_invoice and self.final_invoice_move_id != final_invoice:
+            self.write({'final_invoice_move_id': final_invoice.id})
+
+        if (
+            not final_invoice
+            or final_invoice.state != 'posted'
+            or final_invoice.move_type not in _FINAL_INVOICE_TYPES
+        ):
+            if self.price_adjustment_move_id:
+                self._remove_price_adjustment_entry()
+            return
+
+        stock_input_account_ids = self._get_purchase_stock_input_account_ids()
+        if not stock_input_account_ids:
+            if self.price_adjustment_move_id:
+                self._remove_price_adjustment_entry()
+            return
+
+        self._check_price_adjustment_account_configured(
+            stock_input_account_ids=stock_input_account_ids,
+        )
+        price_adjustment_account = self.company_id.purchase_price_adjustment_account_id
+
+        grni_journal = self.company_id.purchase_grni_adjustment_journal_id
+        if not grni_journal:
+            grni_journal = self.env['account.journal'].search([
+                ('type', '=', 'general'),
+                ('company_id', '=', self.company_id.id),
+            ], limit=1)
+        if not grni_journal:
+            raise UserError(_(
+                'Please configure a GRNI Adjustment Journal for company %s before '
+                'finalising purchase order %s.'
+            ) % (self.company_id.display_name, self.display_name))
+
+        done_moves = self.order_line.mapped('move_ids').filtered(
+            lambda m: m.state == 'done'
+            and m.product_id
+            and m.product_id.type == 'product'
+            and m.product_id.categ_id.property_valuation == 'real_time'
+        )
+        receipt_balances = {}
+        for aml in done_moves.mapped('account_move_ids.line_ids').filtered(
+            lambda l: l.account_id.id in stock_input_account_ids and l.move_id.state == 'posted'
+        ):
+            receipt_balances.setdefault(aml.account_id.id, 0.0)
+            receipt_balances[aml.account_id.id] += aml.balance
+
+        posted_bills = self._get_vendor_bills().filtered(lambda m: m.state == 'posted')
+        invoice_balances = {}
+        if posted_bills:
+            for aml in self.env['account.move.line'].search([
+                ('move_id', 'in', posted_bills.ids),
+                ('account_id', 'in', list(stock_input_account_ids)),
+            ]):
+                invoice_balances.setdefault(aml.account_id.id, 0.0)
+                invoice_balances[aml.account_id.id] += aml.balance
+
+        adjustment_lines = []
+        precision_rounding = self.company_id.currency_id.rounding
+        for account_id in set(receipt_balances) | set(invoice_balances):
+            total_balance = (
+                receipt_balances.get(account_id, 0.0)
+                + invoice_balances.get(account_id, 0.0)
+            )
+            if float_is_zero(total_balance, precision_rounding=precision_rounding):
+                continue
+
+            amount = abs(total_balance)
+            if total_balance > 0:
+                adjustment_lines += [
+                    self._grni_line_vals(final_invoice, price_adjustment_account.id, debit=amount),
+                    self._grni_line_vals(final_invoice, account_id, credit=amount),
+                ]
+            else:
+                adjustment_lines += [
+                    self._grni_line_vals(final_invoice, account_id, debit=amount),
+                    self._grni_line_vals(final_invoice, price_adjustment_account.id, credit=amount),
+                ]
+
+        if adjustment_lines:
+            if self.price_adjustment_move_id:
+                self._remove_price_adjustment_entry()
+
+            adjustment_move = self.env['account.move'].create({
+                'move_type': 'entry',
+                'journal_id': grni_journal.id,
+                'date': final_invoice.date,
+                'ref': _('GRNI Adjustment - Final Invoice %s') % (final_invoice.name or final_invoice.display_name),
+                'line_ids': [(0, 0, vals) for vals in adjustment_lines],
+            })
+            adjustment_move.action_post()
+            self.write({'price_adjustment_move_id': adjustment_move.id})
+        elif self.price_adjustment_move_id:
+            self._remove_price_adjustment_entry()
diff --git a/purchase_invoice_separate_valuation/models/purchase_order_line.py b/purchase_invoice_separate_valuation/models/purchase_order_line.py
new file mode 100644
index 0000000..fe596a8
--- /dev/null
+++ b/purchase_invoice_separate_valuation/models/purchase_order_line.py
@@ -0,0 +1,106 @@
+# -*- coding: utf-8 -*-
+from odoo import api, fields, models
+
+
+class PurchaseOrderLine(models.Model):
+    _inherit = 'purchase.order.line'
+
+    amount_invoiced = fields.Monetary(
+        string='Invoiced Amount',
+        compute='_compute_amount_invoiced',
+        store=True,
+        currency_field='currency_id',
+    )
+    amount_to_invoice = fields.Monetary(
+        string='Amount to Invoice',
+        compute='_compute_amount_invoiced',
+        store=True,
+        currency_field='currency_id',
+    )
+
+    @api.depends(
+        'invoice_lines.move_id.state',
+        'invoice_lines.price_subtotal',
+        'invoice_lines.move_id.currency_id',
+        'invoice_lines.move_id.invoice_date',
+        'invoice_lines.move_id.move_type',
+        'price_subtotal',
+        'order_id.currency_id',
+    )
+    def _compute_amount_invoiced(self):
+        """Compute invoiced amount from ALL posted vendor bills (both partial and final).
+
+        This tracks the actual money invoiced, independent of the qty-based tracking.
+        """
+        for line in self:
+            total = 0.0
+            order = line.order_id
+            if not order:
+                line.amount_invoiced = 0.0
+                line.amount_to_invoice = 0.0
+                continue
+            for inv_line in line._get_invoice_lines():
+                move = inv_line.move_id
+                if move.state != 'posted':
+                    continue
+                if move.move_type not in ('in_invoice', 'in_refund', 'in_receipt'):
+                    continue
+                if move.move_type in ('in_invoice', 'in_receipt'):
+                    amount = inv_line.price_subtotal
+                else:
+                    amount = -inv_line.price_subtotal
+                if move.currency_id != order.currency_id:
+                    amount = move.currency_id._convert(
+                        amount,
+                        order.currency_id,
+                        line.company_id,
+                        move.invoice_date or move.date or fields.Date.context_today(line),
+                    )
+                total += amount
+            line.amount_invoiced = total
+            line.amount_to_invoice = line.price_subtotal - total
+
+    @api.depends(
+        'invoice_lines.move_id.state',
+        'invoice_lines.move_id.is_final_invoice',
+        'invoice_lines.quantity',
+        'qty_received',
+        'product_uom_qty',
+        'order_id.state',
+        'order_id.use_separate_valuation',
+    )
+    def _compute_qty_invoiced(self):
+        """Override qty_invoiced computation.
+
+        For regular orders (use_separate_valuation=False): standard Odoo behaviour.
+        For separate-valuation orders:
+          - Before final invoice: qty_invoiced=0, qty_to_invoice=full pending qty.
+          - After a POSTED final invoice: qty_invoiced=full qty, qty_to_invoice=0,
+            which closes the purchase order's billing status.
+        """
+        separate_lines = self.filtered(lambda l: l.order_id.use_separate_valuation)
+        regular_lines = self - separate_lines
+        if regular_lines:
+            super(PurchaseOrderLine, regular_lines)._compute_qty_invoiced()
+        for line in separate_lines:
+            if line.order_id.state not in ('purchase', 'done'):
+                line.qty_invoiced = 0.0
+                line.qty_to_invoice = 0.0
+                continue
+            has_final_invoice = any(
+                inv_line.move_id.state == 'posted'
+                and inv_line.move_id.is_final_invoice
+                for inv_line in line._get_invoice_lines()
+                if inv_line.move_id.move_type in ('in_invoice', 'in_refund', 'in_receipt')
+            )
+            basis_qty = (
+                line.product_qty
+                if line.product_id.purchase_method == 'purchase'
+                else line.qty_received
+            )
+            if has_final_invoice:
+                line.qty_invoiced = basis_qty
+                line.qty_to_invoice = 0.0
+            else:
+                line.qty_invoiced = 0.0
+                line.qty_to_invoice = basis_qty
diff --git a/purchase_invoice_separate_valuation/models/res_company.py b/purchase_invoice_separate_valuation/models/res_company.py
new file mode 100644
index 0000000..4ea7089
--- /dev/null
+++ b/purchase_invoice_separate_valuation/models/res_company.py
@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+from odoo import fields, models
+
+
+class ResCompany(models.Model):
+    _inherit = 'res.company'
+
+    purchase_price_adjustment_account_id = fields.Many2one(
+        'account.account',
+        string='Purchase Price Adjustment Account',
+        help='Account used for price difference adjustments when posting final vendor bills',
+        domain="[('deprecated', '=', False), ('company_id', '=', id)]",
+    )
+    purchase_grni_adjustment_journal_id = fields.Many2one(
+        'account.journal',
+        string='GRNI Adjustment Journal',
+        help='Journal used for GRNI balancing entries created when a final vendor bill is posted. '
+             'Should be a general/miscellaneous journal, not the accounts payable journal. '
+             'Falls back to the first available general journal if not set.',
+        domain="[('type', '=', 'general'), ('company_id', '=', id)]",
+    )
diff --git a/purchase_invoice_separate_valuation/models/res_config_settings.py b/purchase_invoice_separate_valuation/models/res_config_settings.py
new file mode 100644
index 0000000..0e192cc
--- /dev/null
+++ b/purchase_invoice_separate_valuation/models/res_config_settings.py
@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+from odoo import fields, models
+
+
+class ResConfigSettings(models.TransientModel):
+    _inherit = 'res.config.settings'
+
+    purchase_price_adjustment_account_id = fields.Many2one(
+        'account.account',
+        related='company_id.purchase_price_adjustment_account_id',
+        string='Purchase Price Adjustment Account',
+        readonly=False,
+        help='Default expense account used for price difference adjustments when posting final vendor bills. '
+             'This account will be used instead of the product expense account.',
+        domain="[('deprecated', '=', False), ('company_id', '=', company_id)]",
+    )
+    purchase_grni_adjustment_journal_id = fields.Many2one(
+        'account.journal',
+        related='company_id.purchase_grni_adjustment_journal_id',
+        string='GRNI Adjustment Journal',
+        readonly=False,
+        help='Journal used for GRNI balancing entries created when a final vendor bill is posted. '
+             'Should be a general/miscellaneous journal. Falls back to the first general journal if not set.',
+        domain="[('type', '=', 'general'), ('company_id', '=', company_id)]",
+    )
\ No newline at end of file
diff --git a/purchase_invoice_separate_valuation/models/stock_move.py b/purchase_invoice_separate_valuation/models/stock_move.py
new file mode 100644
index 0000000..c1cb41f
--- /dev/null
+++ b/purchase_invoice_separate_valuation/models/stock_move.py
@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+from odoo import models
+
+
+class StockMove(models.Model):
+    _inherit = 'stock.move'
+
+    def _get_separate_valuation_purchase_orders(self):
+        return (
+            self.mapped('purchase_line_id.order_id')
+            | self.mapped('origin_returned_move_id.purchase_line_id.order_id')
+        ).filtered(lambda po: po.use_separate_valuation and po._get_final_invoice())
+
+    def _action_done(self, cancel_backorder=False):
+        result = super()._action_done(cancel_backorder=cancel_backorder)
+        self._get_separate_valuation_purchase_orders()._sync_price_adjustment_entry()
+        return result
+
+    def _action_cancel(self):
+        purchases = self._get_separate_valuation_purchase_orders()
+        result = super()._action_cancel()
+        purchases._sync_price_adjustment_entry()
+        return result
diff --git a/purchase_invoice_separate_valuation/security/ir.model.access.csv b/purchase_invoice_separate_valuation/security/ir.model.access.csv
new file mode 100644
index 0000000..c7b943c
--- /dev/null
+++ b/purchase_invoice_separate_valuation/security/ir.model.access.csv
@@ -0,0 +1,3 @@
+id,name,model_id:id,group_id:id,perm_read,perm_write,perm_create,perm_unlink
+access_purchase_make_invoice_advance_user,purchase.make_invoice_advance.user,model_purchase_make_invoice_advance,purchase.group_purchase_user,1,1,1,1
+access_purchase_make_invoice_advance_manager,purchase.make_invoice_advance.manager,model_purchase_make_invoice_advance,purchase.group_purchase_manager,1,1,1,1
\ No newline at end of file
diff --git a/purchase_invoice_separate_valuation/views/account_move_views.xml b/purchase_invoice_separate_valuation/views/account_move_views.xml
new file mode 100644
index 0000000..0b76f02
--- /dev/null
+++ b/purchase_invoice_separate_valuation/views/account_move_views.xml
@@ -0,0 +1,69 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+    <!-- Vendor Bill / Credit Note form: Final Invoice controls -->
+    <record id="view_move_form_inherit" model="ir.ui.view">
+        <field name="name">account.move.form.inherit.final.invoice</field>
+        <field name="model">account.move</field>
+        <field name="inherit_id" ref="account.view_move_form"/>
+        <field name="arch" type="xml">
+
+            <!-- Admin buttons in the header (Purchase Manager only) -->
+            <xpath expr="//button[@name='button_draft']" position="after">
+                <button name="action_mark_as_final_invoice"
+                        type="object"
+                        string="Mark as Final Invoice"
+                        class="btn-primary"
+                        groups="purchase.group_purchase_manager"
+                        attrs="{'invisible': ['|',
+                                    ('po_use_separate_valuation', '=', False),
+                                    '|',
+                                    ('is_final_invoice', '=', True),
+                                    '|',
+                                    ('po_has_other_final_invoice', '=', True),
+                                    '|',
+                                    ('state', '!=', 'posted'),
+                                    ('move_type', 'not in', ['in_invoice', 'in_receipt'])
+                                ]}"/>
+                <button name="action_unmark_as_final_invoice"
+                        type="object"
+                        string="Remove Final Invoice Status"
+                        groups="purchase.group_purchase_manager"
+                        attrs="{'invisible': ['|',
+                                    ('is_final_invoice', '=', False),
+                                    '|',
+                                    ('state', '!=', 'posted'),
+                                    ('move_type', 'not in', ['in_invoice', 'in_refund', 'in_receipt'])
+                                ]}"/>
+            </xpath>
+
+            <!-- is_final_invoice field after tax_cash_basis_origin_move_id -->
+            <xpath expr="//field[@name='tax_cash_basis_origin_move_id']" position="after">
+                <field name="is_final_invoice"
+                       readonly="1"
+                       attrs="{'invisible': ['|', ('po_use_separate_valuation', '=', False), ('move_type', 'not in', ['in_invoice', 'in_refund', 'in_receipt'])]}"/>
+                <field name="po_has_other_final_invoice" invisible="1"/>
+                <field name="po_use_separate_valuation" invisible="1"/>
+            </xpath>
+
+            <!-- Price Adjustment Entry in Other Info tab -->
+            <xpath expr="//page[@id='other_tab']//group[@name='accounting_info_group']" position="inside">
+                <field name="price_adjustment_move_id"
+                       readonly="1"
+                       attrs="{'invisible': ['|', ('price_adjustment_move_id', '=', False), ('move_type', 'not in', ['in_invoice', 'in_refund', 'in_receipt'])]}"/>
+            </xpath>
+
+        </field>
+    </record>
+
+    <!-- Vendor Bill list: show Final Invoice column -->
+    <record id="view_in_invoice_tree_inherit" model="ir.ui.view">
+        <field name="name">account.invoice.supplier.tree.inherit.final.invoice</field>
+        <field name="model">account.move</field>
+        <field name="inherit_id" ref="account.view_in_invoice_tree"/>
+        <field name="arch" type="xml">
+            <xpath expr="//field[@name='invoice_date']" position="after">
+                <field name="is_final_invoice" optional="show"/>
+            </xpath>
+        </field>
+    </record>
+</odoo>
diff --git a/purchase_invoice_separate_valuation/views/purchase_views.xml b/purchase_invoice_separate_valuation/views/purchase_views.xml
new file mode 100644
index 0000000..dce51f6
--- /dev/null
+++ b/purchase_invoice_separate_valuation/views/purchase_views.xml
@@ -0,0 +1,76 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+    <!-- Wizard action (button target) -->
+    <record id="action_purchase_make_invoice_advance" model="ir.actions.act_window">
+        <field name="name">Create Invoice (Advanced)</field>
+        <field name="res_model">purchase.make_invoice_advance</field>
+        <field name="view_mode">form</field>
+        <field name="target">new</field>
+    </record>
+
+    <!-- Purchase Order form: add Advanced Invoice button, mode badge, and new fields -->
+    <record id="view_purchase_order_form_inherit" model="ir.ui.view">
+        <field name="name">purchase.order.form.inherit.invoice.wizard</field>
+        <field name="model">purchase.order</field>
+        <field name="inherit_id" ref="purchase.purchase_order_form"/>
+        <field name="arch" type="xml">
+
+            <!-- Hide standard Create Bill buttons when separate valuation is active -->
+            <xpath expr="(//button[@name='action_create_invoice'])[1]" position="attributes">
+                <attribute name="attrs">{'invisible': ['|', '|', ('state', 'not in', ('purchase', 'done')), ('invoice_status', 'in', ('no', 'invoiced')), ('use_separate_valuation', '=', True)]}</attribute>
+            </xpath>
+            <xpath expr="(//button[@name='action_create_invoice'])[2]" position="attributes">
+                <attribute name="attrs">{'invisible': ['|', '|', '|', ('state', 'not in', ('purchase', 'done')), ('invoice_status', 'not in', ('no', 'invoiced')), ('order_line', '=', []), ('use_separate_valuation', '=', True)]}</attribute>
+            </xpath>
+
+            <!-- Advanced invoice button next to the standard one.
+                 Hidden when regular invoices already exist (use_separate_valuation=False and invoice_count>0). -->
+            <xpath expr="(//button[@name='action_create_invoice'])[1]" position="after">
+                <button name="%(action_purchase_make_invoice_advance)d"
+                        type="action"
+                        string="Create Invoice (Advanced)"
+                        class="btn-secondary"
+                        attrs="{'invisible': ['|', '|',
+                                    ('state', 'not in', ['purchase', 'done']),
+                                    ('has_final_invoice', '=', True),
+                                    '&amp;', ('use_separate_valuation', '=', False), ('invoice_count', '>', 0)]}"/>
+            </xpath>
+
+            <!-- Separate Valuation Mode indicator banner -->
+            <xpath expr="//sheet" position="before">
+                <div attrs="{'invisible': [('use_separate_valuation', '=', False)]}"
+                     class="alert alert-info mb-0" role="alert">
+                    <strong>Separate Valuation Mode:</strong>
+                    Use <em>Create Invoice (Advanced)</em> to add invoices.
+                    The standard "Create Invoice" button is blocked for this order.
+                </div>
+            </xpath>
+
+            <!-- Amount totals: invoiced / remaining -->
+            <xpath expr="//field[@name='tax_totals']" position="after">
+                <field name="amount_invoiced" readonly="1"/>
+                <field name="amount_to_invoice" readonly="1"/>
+                <field name="final_invoice_move_id"
+                       readonly="1"
+                       attrs="{'invisible': [('has_final_invoice', '=', False)]}"/>
+                <field name="price_adjustment_move_id"
+                       readonly="1"
+                       attrs="{'invisible': [('price_adjustment_move_id', '=', False)]}"/>
+                <field name="use_separate_valuation" invisible="1"/>
+                <field name="has_final_invoice" invisible="1"/>
+                <field name="price_diff_reason"
+                       attrs="{'invisible': [('use_separate_valuation', '=', False)]}"
+                       placeholder="Reason for price difference between receipt and invoices…"/>
+            </xpath>
+
+            <!-- Order lines: invoiced / remaining columns -->
+            <xpath expr="//field[@name='order_line']/tree//field[@name='price_subtotal']"
+                   position="after">
+                <field name="amount_invoiced" readonly="1" optional="show"/>
+                <field name="amount_to_invoice" readonly="1" optional="show"/>
+            </xpath>
+
+        </field>
+    </record>
+
+</odoo>
diff --git a/purchase_invoice_separate_valuation/views/res_config_settings_views.xml b/purchase_invoice_separate_valuation/views/res_config_settings_views.xml
new file mode 100644
index 0000000..069e64f
--- /dev/null
+++ b/purchase_invoice_separate_valuation/views/res_config_settings_views.xml
@@ -0,0 +1,45 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+    <!-- Add Separate Valuation settings into the existing Vendor Bills section -->
+    <record id="res_config_settings_view_form_inherit" model="ir.ui.view">
+        <field name="name">res.config.settings.view.form.inherit.purchase.price.adjustment</field>
+        <field name="model">res.config.settings</field>
+        <field name="inherit_id" ref="account.res_config_settings_view_form"/>
+        <field name="arch" type="xml">
+            <xpath expr="//div[@id='account_vendor_bills']" position="inside">
+                <div class="col-12 col-lg-6 o_setting_box">
+                    <div class="o_setting_left_pane"/>
+                    <div class="o_setting_right_pane">
+                        <label for="purchase_price_adjustment_account_id"/>
+                        <div class="text-muted">
+                            Account used for price difference adjustments when posting final vendor bills
+                        </div>
+                        <div class="content-group">
+                            <div class="mt16">
+                                <field name="purchase_price_adjustment_account_id"
+                                       class="oe_inline"
+                                       options="{'no_create': True}"/>
+                            </div>
+                        </div>
+                    </div>
+                </div>
+                <div class="col-12 col-lg-6 o_setting_box">
+                    <div class="o_setting_left_pane"/>
+                    <div class="o_setting_right_pane">
+                        <label for="purchase_grni_adjustment_journal_id"/>
+                        <div class="text-muted">
+                            Journal for GRNI balancing entries (general/miscellaneous journal)
+                        </div>
+                        <div class="content-group">
+                            <div class="mt16">
+                                <field name="purchase_grni_adjustment_journal_id"
+                                       class="oe_inline"
+                                       options="{'no_create': True}"/>
+                            </div>
+                        </div>
+                    </div>
+                </div>
+            </xpath>
+        </field>
+    </record>
+</odoo>
\ No newline at end of file
diff --git a/purchase_invoice_separate_valuation/wizards/__init__.py b/purchase_invoice_separate_valuation/wizards/__init__.py
new file mode 100644
index 0000000..53ab466
--- /dev/null
+++ b/purchase_invoice_separate_valuation/wizards/__init__.py
@@ -0,0 +1 @@
+from . import purchase_make_invoice_advance
\ No newline at end of file
diff --git a/purchase_invoice_separate_valuation/wizards/purchase_make_invoice_advance.py b/purchase_invoice_separate_valuation/wizards/purchase_make_invoice_advance.py
new file mode 100644
index 0000000..00377f3
--- /dev/null
+++ b/purchase_invoice_separate_valuation/wizards/purchase_make_invoice_advance.py
@@ -0,0 +1,149 @@
+# -*- coding: utf-8 -*-
+from odoo import api, fields, models, _
+from odoo.exceptions import UserError
+from odoo.tools.float_utils import float_is_zero
+
+
+class PurchaseMakeInvoiceAdvance(models.TransientModel):
+    _name = 'purchase.make_invoice_advance'
+    _description = 'Create Invoice from Purchase Order (Separate Valuation)'
+
+    is_final_invoice = fields.Boolean(
+        string='Final Invoice',
+        default=False,
+        help='Mark as the final invoice for this purchase order. '
+             'This closes the billing cycle and triggers GRNI balancing.',
+    )
+    purchase_order_id = fields.Many2one(
+        'purchase.order',
+        string='Purchase Order',
+        required=True,
+    )
+
+    @api.model
+    def default_get(self, field_names):
+        res = super().default_get(field_names)
+        active_ids = self.env.context.get('active_ids', [])
+        if len(active_ids) > 1:
+            raise UserError(_(
+                'Please open the purchase order form and use the '
+                '"Create Invoice (Advanced)" button there. '
+                'Only one purchase order can be invoiced at a time.'
+            ))
+        if active_ids:
+            res['purchase_order_id'] = active_ids[0]
+        return res
+
+    def create_invoice(self):
+        """Create a vendor bill for the selected purchase order.
+
+        Quantity calculation always uses amount_to_invoice (money-based) so
+        that fractional-quantity rounding never causes a discrepancy between
+        what was already billed and what is proposed next time.
+
+        Lines whose remaining amount is zero or negative are skipped entirely
+        rather than creating zero-amount placeholder lines.
+        """
+        purchase_order = self.purchase_order_id
+        if not purchase_order:
+            raise UserError(_('Please select a purchase order.'))
+
+        purchase_order._check_can_create_advanced_invoice(is_final=self.is_final_invoice)
+
+        invoice_vals = purchase_order._prepare_invoice()
+        invoice_vals['is_final_invoice'] = self.is_final_invoice
+
+        lines_vals = []
+        # Temporary record for _prepare_account_move_line
+        tmp_move = self.env['account.move'].with_context(
+            final_invoice=self.is_final_invoice
+        ).new(invoice_vals)
+
+        for line in purchase_order.order_line.filtered(lambda l: not l.display_type):
+            line_vals = self._prepare_line_vals(line, tmp_move)
+            if line_vals is None:
+                continue
+            lines_vals.append((0, 0, line_vals))
+
+        if not lines_vals:
+            raise UserError(_(
+                'No remaining amount to invoice for %s. '
+                'All lines have already been fully invoiced.'
+            ) % purchase_order.name)
+
+        invoice_vals['invoice_line_ids'] = lines_vals
+        invoice = self.env['account.move'].create(invoice_vals)
+
+        # Flag the purchase order as using separate-valuation mode
+        if not purchase_order.use_separate_valuation:
+            purchase_order.with_context(tracking_disable=True).write(
+                {'use_separate_valuation': True}
+            )
+
+        return self._return_invoice_action(invoice)
+
+    def _prepare_line_vals(self, line, tmp_move):
+        """Return line_vals dict for a single PO line, or None to skip.
+
+        Lines with a zero or negative remaining amount are skipped so that the
+        invoice does not contain confusing zero-price rows.
+
+        For lines with a positive remaining amount the invoice line is always
+        created with qty=1 and price_unit=remaining_amount so that the invoice
+        total is exact regardless of fractional product quantities.
+
+        For products with price-inclusive taxes, amount_to_invoice is
+        tax-exclusive (based on price_subtotal).  The invoice line's price_unit
+        must be the tax-inclusive (gross) amount so that Odoo's tax engine
+        computes the correct price_subtotal when it back-calculates.
+        We achieve this by running compute_all on the inclusive taxes in
+        price-exclusive mode (handle_price_include=False) to obtain the
+        gross-up factor: price_unit = remaining_amount + inclusive_tax_amount.
+        """
+        remaining_amount = line.amount_to_invoice
+        if (
+            float_is_zero(remaining_amount, precision_rounding=line.currency_id.rounding)
+            or remaining_amount <= 0
+        ):
+            return None
+        line_vals = line._prepare_account_move_line(tmp_move)
+
+        # Resolve tax IDs from ORM command format [(6, 0, [ids])]
+        tax_ids = []
+        for cmd in line_vals.get('tax_ids', []):
+            if isinstance(cmd, (list, tuple)):
+                if cmd[0] == 6:
+                    tax_ids = list(cmd[2])
+                elif cmd[0] == 4:
+                    tax_ids.append(cmd[1])
+
+        # For price-inclusive taxes, gross up to the tax-inclusive price_unit.
+        include_taxes = self.env['account.tax'].browse(tax_ids).filtered('price_include')
+        if include_taxes:
+            tax_res = include_taxes.compute_all(
+                remaining_amount,
+                currency=line.currency_id,
+                quantity=1.0,
+                product=line.product_id,
+                partner=line.order_id.partner_id,
+                handle_price_include=False,
+            )
+            price_unit = tax_res['total_included']
+        else:
+            price_unit = remaining_amount
+
+        line_vals['quantity'] = 1.0
+        line_vals['discount'] = 0.0
+        line_vals['price_unit'] = price_unit
+        return line_vals
+
+    @staticmethod
+    def _return_invoice_action(invoice):
+        return {
+            'type': 'ir.actions.act_window',
+            'name': _('Vendor Bills'),
+            'res_model': 'account.move',
+            'view_mode': 'form',
+            'res_id': invoice.id,
+            'target': 'current',
+        }
diff --git a/purchase_invoice_separate_valuation/wizards/purchase_make_invoice_advance_views.xml b/purchase_invoice_separate_valuation/wizards/purchase_make_invoice_advance_views.xml
new file mode 100644
index 0000000..fcec4df
--- /dev/null
+++ b/purchase_invoice_separate_valuation/wizards/purchase_make_invoice_advance_views.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+    <!-- Wizard Form View -->
+    <record id="purchase_make_invoice_advance_form" model="ir.ui.view">
+        <field name="name">purchase.make_invoice_advance.form</field>
+        <field name="model">purchase.make_invoice_advance</field>
+        <field name="arch" type="xml">
+            <form string="Create Invoice">
+                <group>
+                    <field name="purchase_order_id" options="{'no_create': True}" readonly="1"/>
+                    <field name="is_final_invoice"/>
+                    <div colspan="2" class="alert alert-info" role="alert" attrs="{'invisible': [('is_final_invoice', '=', False)]}">
+                        <strong>Final Invoice:</strong> This will update purchase order quantities and may close the purchase order.
+                    </div>
+                    <div colspan="2" class="alert alert-warning" role="alert" attrs="{'invisible': [('is_final_invoice', '=', True)]}">
+                        <strong>Partial Invoice:</strong> Purchase order quantities will not be updated. You can create multiple invoices.
+                    </div>
+                </group>
+                <footer>
+                    <button name="create_invoice" type="object" string="Create Invoice" class="btn-primary"/>
+                    <button string="Cancel" class="btn-secondary" special="cancel"/>
+                </footer>
+            </form>
+        </field>
+    </record>
+</odoo>
\ No newline at end of file