diff --git a/rental_deposit/__init__.py b/rental_deposit/__init__.py
new file mode 100644
index 00000000000..0650744f6bc
--- /dev/null
+++ b/rental_deposit/__init__.py
@@ -0,0 +1 @@
+from . import models
diff --git a/rental_deposit/__manifest__.py b/rental_deposit/__manifest__.py
new file mode 100644
index 00000000000..119f6714ddb
--- /dev/null
+++ b/rental_deposit/__manifest__.py
@@ -0,0 +1,18 @@
+{
+    'author': 'Aditi (adpaw)',
+    'name': 'Deposit Rental App',
+    'license': 'LGPL-3',
+    'depends': ['sale_renting', 'website_sale'],
+    'data': [
+        'views/res_config_settings_view.xml',
+        'views/product_template_view.xml',
+        'views/template_view.xml'
+    ],
+    'assets': {
+        'web.assets_frontend': [
+            'rental_deposit/static/src/deposit_amount.js',
+        ],
+    },
+    'installable': True,
+    'auto_install': True,
+}
diff --git a/rental_deposit/models/__init__.py b/rental_deposit/models/__init__.py
new file mode 100644
index 00000000000..90b06a9bf48
--- /dev/null
+++ b/rental_deposit/models/__init__.py
@@ -0,0 +1,4 @@
+from . import res_config_settings
+from . import product_template
+from . import sale_order_line
+from . import res_company
diff --git a/rental_deposit/models/product_template.py b/rental_deposit/models/product_template.py
new file mode 100644
index 00000000000..76d32810754
--- /dev/null
+++ b/rental_deposit/models/product_template.py
@@ -0,0 +1,8 @@
+from odoo import fields, models
+
+
+class ProductTemplate(models.Model):
+    _inherit = 'product.template'
+
+    requires_deposit = fields.Boolean(string="Requires Deposit")
+    deposit_amount = fields.Float()
diff --git a/rental_deposit/models/res_company.py b/rental_deposit/models/res_company.py
new file mode 100644
index 00000000000..20d11bd60a1
--- /dev/null
+++ b/rental_deposit/models/res_company.py
@@ -0,0 +1,7 @@
+from odoo import fields, models
+
+
+class ResCompany(models.Model):
+    _inherit = "res.company"
+
+    deposit_product = fields.Many2one("product.product")
diff --git a/rental_deposit/models/res_config_settings.py b/rental_deposit/models/res_config_settings.py
new file mode 100644
index 00000000000..35ef96e4b71
--- /dev/null
+++ b/rental_deposit/models/res_config_settings.py
@@ -0,0 +1,12 @@
+from odoo import fields, models
+
+
+class ResConfigSettings(models.TransientModel):
+    _inherit = 'res.config.settings'
+
+    deposit_product = fields.Many2one(
+        "product.product",
+        related="company_id.deposit_product",
+        string="Deposit",
+        readonly=False
+    )
diff --git a/rental_deposit/models/sale_order_line.py b/rental_deposit/models/sale_order_line.py
new file mode 100644
index 00000000000..2eb4904c8a8
--- /dev/null
+++ b/rental_deposit/models/sale_order_line.py
@@ -0,0 +1,94 @@
+from odoo import api, fields, models
+from odoo.exceptions import UserError
+
+
+class SaleOrderLine(models.Model):
+    _inherit = 'sale.order.line'
+
+    is_deposit_line = fields.Boolean(default=False)
+    parent_rental_line_id = fields.Many2one(
+        'sale.order.line',
+        string="Parent Rental Line",
+        ondelete="cascade",
+        index=True
+    )
+
+    @api.model_create_multi
+    def create(self, vals_list):
+        lines = super().create(vals_list)
+        rental_lines = lines.filtered(
+            lambda l: l.product_id.rent_ok
+            and l.product_id.requires_deposit
+            and l.product_id.deposit_amount > 0
+            and not l.is_deposit_line
+        )
+        if not rental_lines:
+            return lines
+        company_map = {}
+        for line in rental_lines:
+            company = line.company_id
+            if company not in company_map:
+                if not company.deposit_product:
+                    raise UserError("Please set deposit product in settings.")
+                company_map[company] = company.deposit_product
+        deposit_vals = []
+        for line in rental_lines:
+            deposit_product = company_map[line.company_id]
+            deposit_vals.append({
+                'order_id': line.order_id.id,
+                'product_id': deposit_product.id,
+                'product_uom_qty': line.product_uom_qty,
+                'price_unit': line.product_id.deposit_amount,
+                'name': f"Deposit fee for product: {line.product_id.name}",
+                'is_deposit_line': True,
+                'parent_rental_line_id': line.id,
+            })
+        self.create(deposit_vals)
+        return lines
+
+        # deposit_vals = []
+        # for line in rental_lines:
+        #     deposit_product = line.company_id.deposit_product
+        #     if not deposit_product:
+        #         raise UserError("Please set deposit product in settings.")
+        #     deposit_vals.append({
+        #         'order_id': line.order_id.id,
+        #         'product_id': deposit_product.id,
+        #         'product_uom_qty': line.product_uom_qty,
+        #         'price_unit': line.product_id.deposit_amount,
+        #         'name': f"Deposit fee for product: {line.product_id.name}",
+        #         'is_deposit_line': True,
+        #         'parent_rental_line_id': line.id,
+        #     })
+        # self.create(deposit_vals)
+        # return lines
+
+    @api.ondelete(at_uninstall=False)
+    def _unlink_deposit_fee(self):
+        if not self.env.context.get("bypass_deposit_protection_for_delete"):
+            for record in self:
+                if record.is_deposit_line:
+                    raise UserError("You can't delete a Deposit Product line directly.")
+
+    def write(self, vals):
+        if not self.env.context.get("bypass_deposit_protection_for_write"):
+            for record in self:
+                if record.is_deposit_line:
+                    raise UserError("You can't edit Deposit Product line directly.")
+        res = super().write(vals)
+        if 'product_uom_qty' not in vals:
+            return res
+        rental_lines = self.filtered(
+            lambda l: l.product_id.rent_ok
+            and l.product_id.requires_deposit
+            and l.product_id.deposit_amount > 0
+            and not l.is_deposit_line
+        )
+        for line in rental_lines:
+            deposit_line = self.search([('parent_rental_line_id', '=', line.id)], limit=1)
+            if deposit_line:
+                deposit_line.with_context(bypass_deposit_protection_for_write=True).write({
+                    'product_uom_qty': line.product_uom_qty,
+                    'price_unit': line.product_id.deposit_amount,
+                })
+        return res
diff --git a/rental_deposit/static/src/deposit_amount.js b/rental_deposit/static/src/deposit_amount.js
new file mode 100644
index 00000000000..af0a325e752
--- /dev/null
+++ b/rental_deposit/static/src/deposit_amount.js
@@ -0,0 +1,27 @@
+import { Component, onMounted } from "@odoo/owl";
+import { registry } from "@web/core/registry";
+
+export class DepositAmount extends Component {
+    setup() {
+        onMounted(() => {
+            const depositEl = document.querySelector('#deposit_amount_val');
+            const qtyInput = document.querySelector('input[name="add_qty"]');
+
+            if (!depositEl || !qtyInput) return;
+
+            const baseAmount = parseFloat(depositEl.dataset.baseAmount) || 0;
+
+            const calculateTotal = () => {
+                const quantity = parseFloat(qtyInput.value) || 1;
+                depositEl.textContent = (baseAmount * quantity).toFixed(2);
+            };
+
+            qtyInput.addEventListener('input', calculateTotal);
+            qtyInput.addEventListener('change', calculateTotal);
+
+            calculateTotal();
+        });
+    }
+}
+
+registry.category("public_components").add("deposit_amount", DepositAmount);
diff --git a/rental_deposit/tests/__init__.py b/rental_deposit/tests/__init__.py
new file mode 100644
index 00000000000..0c75457509d
--- /dev/null
+++ b/rental_deposit/tests/__init__.py
@@ -0,0 +1,2 @@
+from . import common
+from . import test_sale_order_line
diff --git a/rental_deposit/tests/common.py b/rental_deposit/tests/common.py
new file mode 100644
index 00000000000..e5c8684b16b
--- /dev/null
+++ b/rental_deposit/tests/common.py
@@ -0,0 +1,57 @@
+from odoo.tests.common import TransactionCase
+
+
+class RentalDepositCommon(TransactionCase):
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+
+        cls.deposit_product = cls.env['product.product'].create({
+            'name': 'Deposit Fee',
+            'type': 'service',
+        })
+        cls.env.company.deposit_product = cls.deposit_product
+
+        cls.rental_product_a = cls.env['product.product'].create({
+            'name': 'Test Projector',
+            'rent_ok': True,
+            'requires_deposit': True,
+            'deposit_amount': 50.0,
+        })
+
+        cls.rental_product_b = cls.env['product.product'].create({
+            'name': 'Test Bike',
+            'rent_ok': True,
+            'requires_deposit': True,
+            'deposit_amount': 30.0,
+        })
+
+        cls.rental_product_c = cls.env['product.product'].create({
+            'name': 'Test Camera',
+            'rent_ok': True,
+            'requires_deposit': True,
+            'deposit_amount': 20.0,
+        })
+
+        cls.rental_no_deposit = cls.env['product.product'].create({
+            'name': 'Test Chair',
+            'rent_ok': True,
+            'requires_deposit': False,
+        })
+
+        cls.partner = cls.env['res.partner'].create({'name': 'Test Customer'})
+
+    def _make_order(self):
+        """Creates a fresh sale order each time."""
+        return self.env['sale.order'].create({
+            'partner_id': self.partner.id,
+        })
+
+    def _add_line(self, order, product, qty=1, price=10.0):
+        """Helper — adds a single order line and returns it."""
+        return self.env['sale.order.line'].create({
+            'order_id': order.id,
+            'product_id': product.id,
+            'product_uom_qty': qty,
+            'price_unit': price,
+        })
diff --git a/rental_deposit/tests/test_sale_order_line.py b/rental_deposit/tests/test_sale_order_line.py
new file mode 100644
index 00000000000..6fa42346bce
--- /dev/null
+++ b/rental_deposit/tests/test_sale_order_line.py
@@ -0,0 +1,195 @@
+from odoo.exceptions import UserError
+
+from .common import RentalDepositCommon
+
+
+class TestSaleOrderLine(RentalDepositCommon):
+
+    # single product
+
+    def test_deposit_line_created_on_rental_product_add(self):
+        # adding single rental product to create one deposit line
+        order = self._make_order()
+        self._add_line(order, self.rental_product_a)
+
+        deposit_lines = order.order_line.filtered(lambda l: l.is_deposit_line)
+        self.assertEqual(len(deposit_lines), 1)
+        self.assertEqual(deposit_lines.price_unit, 50.0)
+
+    def test_deposit_line_linked_to_parent_rental_line(self):
+        order = self._make_order()
+        rental_line = self._add_line(order, self.rental_product_a)
+
+        deposit_line = order.order_line.filtered(lambda l: l.is_deposit_line)
+        self.assertEqual(deposit_line.parent_rental_line_id, rental_line)
+
+    def test_no_deposit_line_for_non_deposit_product(self):
+        order = self._make_order()
+        self._add_line(order, self.rental_no_deposit)
+
+        deposit_lines = order.order_line.filtered(lambda l: l.is_deposit_line)
+        self.assertEqual(len(deposit_lines), 0)
+
+    def test_deposit_line_qty_syncs_on_write(self):
+        order = self._make_order()
+        rental_line = self._add_line(order, self.rental_product_a, qty=1)
+
+        rental_line.write({'product_uom_qty': 3})
+
+        deposit_line = order.order_line.filtered(lambda l: l.is_deposit_line)
+        self.assertEqual(deposit_line.product_uom_qty, 3)
+
+    def test_deposit_line_deleted_with_rental_line(self):
+        # deposit line should be removed via cascade
+        order = self._make_order()
+        rental_line = self._add_line(order, self.rental_product_a)
+
+        rental_line.unlink()
+
+        deposit_lines = order.order_line.filtered(lambda l: l.is_deposit_line)
+        self.assertEqual(len(deposit_lines), 0)
+
+    def test_direct_edit_of_deposit_line_raises_error(self):
+        order = self._make_order()
+        self._add_line(order, self.rental_product_a)
+
+        deposit_line = order.order_line.filtered(lambda l: l.is_deposit_line)
+        with self.assertRaises(UserError):
+            deposit_line.write({'price_unit': 999})
+
+    def test_direct_delete_of_deposit_line_raises_error(self):
+        order = self._make_order()
+        self._add_line(order, self.rental_product_a)
+
+        deposit_line = order.order_line.filtered(lambda l: l.is_deposit_line)
+        with self.assertRaises(UserError):
+            deposit_line.unlink()
+
+    def test_error_when_deposit_product_not_configured(self):
+        self.env.company.deposit_product = False
+        order = self._make_order()
+
+        with self.assertRaises(UserError):
+            self._add_line(order, self.rental_product_a)
+
+        # reset so other tests aren't affected
+        self.env.company.deposit_product = self.deposit_product
+
+    # multiple products
+
+    def test_multiple_deposit_lines_for_multiple_products(self):
+        order = self._make_order()
+        self._add_line(order, self.rental_product_a)
+        self._add_line(order, self.rental_product_b)
+        self._add_line(order, self.rental_product_c)
+
+        deposit_lines = order.order_line.filtered(lambda l: l.is_deposit_line)
+        self.assertEqual(len(deposit_lines), 3)
+
+    def test_each_deposit_line_linked_to_correct_parent(self):
+        order = self._make_order()
+        line_a = self._add_line(order, self.rental_product_a)
+        line_b = self._add_line(order, self.rental_product_b)
+
+        deposit_a = order.order_line.filtered(
+            lambda l: l.is_deposit_line and l.parent_rental_line_id == line_a
+        )
+        deposit_b = order.order_line.filtered(
+            lambda l: l.is_deposit_line and l.parent_rental_line_id == line_b
+        )
+        self.assertEqual(len(deposit_a), 1)
+        self.assertEqual(len(deposit_b), 1)
+
+    def test_deposit_amounts_correct_for_multiple_products(self):
+        order = self._make_order()
+        self._add_line(order, self.rental_product_a)
+        self._add_line(order, self.rental_product_b)
+        self._add_line(order, self.rental_product_c)
+
+        deposit_lines = order.order_line.filtered(lambda l: l.is_deposit_line)
+        self.assertEqual(sorted(deposit_lines.mapped('price_unit')), [20.0, 30.0, 50.0])
+
+    def test_mix_of_deposit_and_non_deposit_products(self):
+        order = self._make_order()
+        self._add_line(order, self.rental_product_a)
+        self._add_line(order, self.rental_no_deposit)
+        self._add_line(order, self.rental_product_b)
+
+        deposit_lines = order.order_line.filtered(lambda l: l.is_deposit_line)
+        self.assertEqual(len(deposit_lines), 2)
+
+    def test_no_duplicate_deposit_lines_on_resave(self):
+        # write() is called again when the order is saved — make sure
+        # it doesn't create a second deposit line for the same rental line
+        order = self._make_order()
+        self._add_line(order, self.rental_product_a)
+
+        order.write({'note': 'updated'})
+
+        deposit_lines = order.order_line.filtered(lambda l: l.is_deposit_line)
+        self.assertEqual(len(deposit_lines), 1)
+
+    def test_qty_sync_per_product_independently(self):
+        order = self._make_order()
+        line_a = self._add_line(order, self.rental_product_a, qty=1)
+        line_b = self._add_line(order, self.rental_product_b, qty=1)
+
+        line_a.write({'product_uom_qty': 4})
+        line_b.write({'product_uom_qty': 2})
+
+        deposit_a = order.order_line.filtered(
+            lambda l: l.is_deposit_line and l.parent_rental_line_id == line_a
+        )
+        deposit_b = order.order_line.filtered(
+            lambda l: l.is_deposit_line and l.parent_rental_line_id == line_b
+        )
+        self.assertEqual(deposit_a.product_uom_qty, 4)
+        self.assertEqual(deposit_b.product_uom_qty, 2)
+
+    def test_qty_change_on_one_does_not_affect_other(self):
+        order = self._make_order()
+        line_a = self._add_line(order, self.rental_product_a, qty=1)
+        line_b = self._add_line(order, self.rental_product_b, qty=1)
+
+        line_a.write({'product_uom_qty': 5})
+
+        deposit_b = order.order_line.filtered(
+            lambda l: l.is_deposit_line and l.parent_rental_line_id == line_b
+        )
+        self.assertEqual(deposit_b.product_uom_qty, 1)
+
+    def test_deleting_one_line_removes_only_its_deposit(self):
+        order = self._make_order()
+        line_a = self._add_line(order, self.rental_product_a)
+        line_b = self._add_line(order, self.rental_product_b)
+
+        line_a.unlink()
+
+        deposit_lines = order.order_line.filtered(lambda l: l.is_deposit_line)
+        self.assertEqual(len(deposit_lines), 1)
+        self.assertEqual(deposit_lines.parent_rental_line_id, line_b)
+
+    def test_deleting_all_lines_removes_all_deposits(self):
+        order = self._make_order()
+        line_a = self._add_line(order, self.rental_product_a)
+        line_b = self._add_line(order, self.rental_product_b)
+        line_c = self._add_line(order, self.rental_product_c)
+
+        (line_a | line_b | line_c).unlink()
+
+        deposit_lines = order.order_line.filtered(lambda l: l.is_deposit_line)
+        self.assertEqual(len(deposit_lines), 0)
+
+    def test_deleting_rental_line_keeps_non_deposit_line(self):
+        # make sure cascade only removes the deposit line tied to the deleted
+        # rental line, not unrelated lines on the same order
+        order = self._make_order()
+        line_a = self._add_line(order, self.rental_product_a)
+        self._add_line(order, self.rental_no_deposit)
+
+        line_a.unlink()
+
+        remaining = order.order_line.filtered(
+            lambda l: l.product_id == self.rental_no_deposit
+        )
+        self.assertEqual(len(remaining), 1)
diff --git a/rental_deposit/views/product_template_view.xml b/rental_deposit/views/product_template_view.xml
new file mode 100644
index 00000000000..2b699cf135c
--- /dev/null
+++ b/rental_deposit/views/product_template_view.xml
@@ -0,0 +1,13 @@
+<odoo>
+    <record id="product_template_form_view_rental_deposit" model="ir.ui.view">
+        <field name="name">product.template.view.form.inherit.rental.deposit</field>
+        <field name="model">product.template</field>
+        <field name="inherit_id" ref="product.product_template_only_form_view"/>
+        <field name="arch" type="xml">
+            <xpath expr="//group[@name='extra_rental']" position="inside">
+                <field name="requires_deposit"/>
+                <field name="deposit_amount" invisible="not requires_deposit" widget="monetary"/>
+            </xpath>
+        </field>
+    </record>
+</odoo>
diff --git a/rental_deposit/views/res_config_settings_view.xml b/rental_deposit/views/res_config_settings_view.xml
new file mode 100644
index 00000000000..0688dc17ab3
--- /dev/null
+++ b/rental_deposit/views/res_config_settings_view.xml
@@ -0,0 +1,13 @@
+<odoo>
+    <record id="res_config_settings_view_form_deposit_inherit" model="ir.ui.view">
+        <field name="name">res.config.settings.view.form.inherit.deposit</field>
+        <field name="model">res.config.settings</field>
+        <field name="inherit_id" ref="base.res_config_settings_view_form"/>
+        <field name="arch" type="xml">
+            <xpath expr="//field[@name='extra_product']" position="after">
+                <label for="deposit_product"/>
+                <field name="deposit_product"/>
+            </xpath>
+        </field>
+    </record>
+</odoo>
diff --git a/rental_deposit/views/template_view.xml b/rental_deposit/views/template_view.xml
new file mode 100644
index 00000000000..cbf184db8ea
--- /dev/null
+++ b/rental_deposit/views/template_view.xml
@@ -0,0 +1,18 @@
+<odoo>
+    <template id="rental_product_details_inherited" inherit_id="website_sale.product">
+        <xpath expr="//t[@t-call='website_sale.cta_wrapper']" position="after">
+            <t t-if="product.rent_ok and product.requires_deposit">
+                
+                <div class="mt-2" t-component="deposit_amount">
+                    <strong>Deposit Required: </strong>
+                    <span t-out="product.currency_id.symbol"/> 
+                    
+                    <span id="deposit_amount_val" 
+                        t-att-data-base-amount="product.deposit_amount" 
+                        t-out="'%.2f' % product.deposit_amount"/>
+                </div>
+
+            </t>
+        </xpath>
+    </template>
+</odoo>