diff --git a/addons/sale/models/sale_order.py b/addons/sale/models/sale_order.py
index ddcede255c6..3607b0c47d8 100644
--- a/addons/sale/models/sale_order.py
+++ b/addons/sale/models/sale_order.py
@@ -1022,8 +1022,9 @@ class SaleOrder(models.Model):
             'invoice_line_ids': [],
         }
 
-    def action_view_invoice(self):
-        invoices = self.mapped('invoice_ids')
+    def action_view_invoice(self, invoices=False):
+        if not invoices:
+            invoices = self.mapped('invoice_ids')
         action = self.env['ir.actions.actions']._for_xml_id('account.action_move_out_invoice_type')
         if len(invoices) > 1:
             action['domain'] = [('id', 'in', invoices.ids)]
diff --git a/addons/sale/models/sale_order_line.py b/addons/sale/models/sale_order_line.py
index 21eb4bee9bf..57ffa16b05c 100644
--- a/addons/sale/models/sale_order_line.py
+++ b/addons/sale/models/sale_order_line.py
@@ -572,7 +572,7 @@ class SaleOrderLine(models.Model):
                     # otherwise it's a surcharge which shouldn't be shown to the customer
                     line.discount = discount
 
-    def _convert_to_tax_base_line_dict(self):
+    def _convert_to_tax_base_line_dict(self, **kwargs):
         """ Convert the current record to a dictionary in order to use the generic taxes computation method
         defined on account.tax.
 
@@ -589,6 +589,7 @@ class SaleOrderLine(models.Model):
             quantity=self.product_uom_qty,
             discount=self.discount,
             price_subtotal=self.price_subtotal,
+            **kwargs,
         )
 
     @api.depends('product_uom_qty', 'discount', 'price_unit', 'tax_id')
diff --git a/addons/sale/tests/__init__.py b/addons/sale/tests/__init__.py
index ed2b40060bd..9348f7d6e16 100644
--- a/addons/sale/tests/__init__.py
+++ b/addons/sale/tests/__init__.py
@@ -16,3 +16,4 @@ from . import test_sale_product_attribute_value_config
 from . import test_sale_refund
 from . import test_sale_tax_totals
 from . import test_sale_to_invoice
+from . import test_sale_order_down_payment
diff --git a/addons/sale/tests/test_sale_order_down_payment.py b/addons/sale/tests/test_sale_order_down_payment.py
new file mode 100644
index 00000000000..e23aec7c2e5
--- /dev/null
+++ b/addons/sale/tests/test_sale_order_down_payment.py
@@ -0,0 +1,405 @@
+from odoo.tests import tagged
+from odoo import Command
+from .common import TestSaleCommon
+
+
+@tagged('post_install', '-at_install')
+class TestSaleOrderDownPayment(TestSaleCommon):
+
+    @classmethod
+    def setUpClass(cls, chart_template_ref=None):
+        super().setUpClass(chart_template_ref=chart_template_ref)
+
+        SaleOrder = cls.env['sale.order'].with_context(tracking_disable=True)
+
+        cls.tax_10 = cls.create_tax(10)
+        cls.tax_15 = cls.create_tax(15)
+
+        # create a generic Sale Order with all classical products and empty pricelist
+        cls.sale_order = SaleOrder.create({
+            'partner_id': cls.partner_a.id,
+            'partner_invoice_id': cls.partner_a.id,
+            'partner_shipping_id': cls.partner_a.id,
+            'pricelist_id': cls.company_data['default_pricelist'].id,
+        })
+        cls.sol_product_order = cls.env['sale.order.line'].create({
+            'name': cls.company_data['product_order_no'].name,
+            'product_id': cls.company_data['product_order_no'].id,
+            'product_uom_qty': 2,
+            'product_uom': cls.company_data['product_order_no'].uom_id.id,
+            'price_unit': 100,
+            'order_id': cls.sale_order.id,
+            'tax_id': False,
+        })
+        cls.sol_serv_deliver = cls.env['sale.order.line'].create({
+            'name': cls.company_data['product_service_delivery'].name,
+            'product_id': cls.company_data['product_service_delivery'].id,
+            'product_uom_qty': 2,
+            'product_uom': cls.company_data['product_service_delivery'].uom_id.id,
+            'price_unit': 100,
+            'order_id': cls.sale_order.id,
+            'tax_id': False,
+        })
+        cls.sol_serv_order = cls.env['sale.order.line'].create({
+            'name': cls.company_data['product_service_order'].name,
+            'product_id': cls.company_data['product_service_order'].id,
+            'product_uom_qty': 2,
+            'product_uom': cls.company_data['product_service_order'].uom_id.id,
+            'price_unit': 100,
+            'order_id': cls.sale_order.id,
+            'tax_id': False,
+        })
+        cls.sol_product_deliver = cls.env['sale.order.line'].create({
+            'name': cls.company_data['product_delivery_no'].name,
+            'product_id': cls.company_data['product_delivery_no'].id,
+            'product_uom_qty': 2,
+            'product_uom': cls.company_data['product_delivery_no'].uom_id.id,
+            'price_unit': 100,
+            'order_id': cls.sale_order.id,
+            'tax_id': False,
+        })
+
+        cls.revenue_account = cls.company_data['default_account_revenue']
+        cls.receivable_account = cls.company_data['default_account_receivable']
+
+    @classmethod
+    def create_tax(cls, amount, values=None):
+        vals = {
+            'name': 'Tax %s' % amount,
+            'amount_type': 'percent',
+            'amount': amount,
+            'type_tax_use': 'sale',
+        }
+        if values:
+            vals.update(values)
+        return cls.env['account.tax'].create(vals)
+
+    @classmethod
+    def make_downpayment(cls, **kwargs):
+        so_context = {
+            'active_model': 'sale.order',
+            'active_ids': [cls.sale_order.id],
+            'active_id': cls.sale_order.id,
+            'default_journal_id': cls.company_data['default_journal_sale'].id,
+        }
+        payment_params = {
+            'advance_payment_method': 'percentage',
+            'amount': 50,
+            'deposit_account_id': cls.revenue_account.id,
+            **kwargs,
+        }
+        downpayment = cls.env['sale.advance.payment.inv'].with_context(so_context).create(payment_params)
+        downpayment.create_invoices()
+        cls.sale_order.action_confirm()
+
+    def _assert_invoice_lines_values(self, lines, expected):
+        return self.assertRecordValues(lines, [dict(zip(expected[0], x)) for x in expected[1:]])
+
+    def test_tax_breakdown(self):
+        self.sale_order.order_line[0].tax_id = self.tax_15 + self.tax_10
+        self.sale_order.order_line[1].tax_id = self.tax_10
+        self.sale_order.order_line[2].tax_id = self.tax_10
+        self.make_downpayment()
+        invoice = self.sale_order.invoice_ids
+        down_pay_amt = self.sale_order.amount_total / 2
+        # pylint: disable=C0326
+        expected = [
+            # keys
+            ['account_id',               'tax_ids',                      'balance',     'price_total'],
+            # base lines
+            [self.revenue_account.id,    (self.tax_15 + self.tax_10).ids, -100,         125          ],
+            [self.revenue_account.id,    self.tax_10.ids,                 -200,         220          ],
+            [self.revenue_account.id,    self.env['account.tax'],         -100,         100          ],
+            # taxes
+            [self.revenue_account.id,    self.env['account.tax'],         -30,          0            ],
+            [self.revenue_account.id,    self.env['account.tax'],         -15,          0            ],
+            # receivable
+            [self.receivable_account.id, self.env['account.tax'],         down_pay_amt, 0            ],
+        ]
+        self._assert_invoice_lines_values(invoice.line_ids, expected)
+
+    def test_tax_breakdown_other_currency(self):
+        self.sale_order.currency_id = self.currency_data['currency']  # rate = 2.0
+        self.sale_order.order_line[0].tax_id = self.tax_15 + self.tax_10
+        self.sale_order.order_line[1].tax_id = self.tax_10
+        self.sale_order.order_line[2].tax_id = self.tax_10
+        self.make_downpayment()
+        invoice = self.sale_order.invoice_ids
+        down_pay_amt = self.sale_order.amount_total / 2
+        # pylint: disable=C0326
+        expected = [
+            # keys
+            ['account_id',               'tax_ids',                      'balance',           'price_total'],
+            # base lines
+            [self.revenue_account.id,    (self.tax_15 + self.tax_10).ids, -50,                125          ],
+            [self.revenue_account.id,    self.tax_10.ids,                 -100,               220          ],
+            [self.revenue_account.id,    self.env['account.tax'],         -50,                100          ],
+            # taxes
+            [self.revenue_account.id,    self.env['account.tax'],         -15,                0            ],
+            [self.revenue_account.id,    self.env['account.tax'],         -7.5,               0            ],
+            # receivable
+            [self.receivable_account.id, self.env['account.tax'],         down_pay_amt / 2.0, 0            ],
+        ]
+        self._assert_invoice_lines_values(invoice.line_ids, expected)
+
+    def test_tax_breakdown_fixed_payment_method(self):
+        self.sale_order.order_line[0].tax_id = self.tax_15 + self.tax_10
+        self.sale_order.order_line[1].tax_id = self.tax_10
+        self.sale_order.order_line[2].tax_id = self.tax_10
+        self.make_downpayment(advance_payment_method='fixed', fixed_amount=222.5, amount=0)
+        invoice = self.sale_order.invoice_ids
+        down_pay_amt = 222.5
+        # pylint: disable=C0326
+        expected = [
+            # keys
+            ['account_id',               'tax_ids',                      'balance',     'price_total'],
+            # base lines
+            [self.revenue_account.id,    (self.tax_15 + self.tax_10).ids, -50,          62.5         ],
+            [self.revenue_account.id,    self.tax_10.ids,                 -100,         110          ],
+            [self.revenue_account.id,    self.env['account.tax'],         -50,          50           ],
+            # taxes
+            [self.revenue_account.id,    self.env['account.tax'],         -15,          0            ],
+            [self.revenue_account.id,    self.env['account.tax'],         -7.5,         0            ],
+            # receivable
+            [self.receivable_account.id, self.env['account.tax'],         down_pay_amt, 0            ],
+        ]
+        self._assert_invoice_lines_values(invoice.line_ids, expected)
+
+    def test_tax_breakdown_fixed_payment_method_with_taxes_on_all_lines(self):
+        self.sale_order.order_line[0].tax_id = self.tax_15
+        self.sale_order.order_line[1].tax_id = self.tax_10
+        self.sale_order.order_line[2].tax_id = self.tax_10
+        self.sale_order.order_line[3].tax_id = self.tax_10
+        self.make_downpayment(advance_payment_method='fixed', fixed_amount=222.5, amount=0)
+        invoice = self.sale_order.invoice_ids
+        down_pay_amt = 222.5
+        # pylint: disable=C0326
+        expected = [
+            # keys
+            ['account_id',               'tax_ids',              'balance',     'price_total'],
+            # base lines
+            [self.revenue_account.id,    self.tax_15.ids,         -50,          57.5         ],
+            [self.revenue_account.id,    self.tax_10.ids,         -150,         165          ],
+            # taxes
+            [self.revenue_account.id,    self.env['account.tax'], -7.5,         0            ],
+            [self.revenue_account.id,    self.env['account.tax'], -15,          0            ],
+            # receivable
+            [self.receivable_account.id, self.env['account.tax'], down_pay_amt, 0            ],
+        ]
+        self._assert_invoice_lines_values(invoice.line_ids, expected)
+
+    def test_tax_price_include_breakdown(self):
+        tax_10_incl = self.create_tax(10, {'price_include': True})
+        self.sale_order.order_line[0].tax_id = tax_10_incl + self.tax_10
+        self.sale_order.order_line[1].tax_id = self.tax_10
+        self.sale_order.order_line[2].tax_id = self.tax_10
+        self.make_downpayment()
+        invoice = self.sale_order.invoice_ids
+        down_pay_amt = self.sale_order.amount_total / 2
+        # pylint: disable=C0326
+        expected = [
+            # keys
+            ['account_id',               'tax_ids',                       'balance',    'price_total'],
+            # base lines
+            [self.revenue_account.id,    (tax_10_incl + self.tax_10).ids, -90.91,       109.09       ],
+            [self.revenue_account.id,    self.tax_10.ids,                 -200,         220          ],
+            [self.revenue_account.id,    self.env['account.tax'],         -100,         100          ],
+            # taxes
+            [self.revenue_account.id,    self.env['account.tax'],         -29.09,       0            ],
+            [self.revenue_account.id,    self.env['account.tax'],         -9.09,        0            ],
+            # receivable
+            [self.receivable_account.id, self.env['account.tax'],         down_pay_amt, 0            ],
+        ]
+        self._assert_invoice_lines_values(invoice.line_ids, expected)
+
+    def test_tax_price_include_include_base_amount_breakdown(self):
+        tax_10_pi_ba = self.create_tax(10, {'price_include': True, 'include_base_amount': True})
+        self.tax_10.sequence = 2
+        self.sale_order.order_line[0].tax_id = tax_10_pi_ba + self.tax_10
+        self.sale_order.order_line[1].tax_id = self.tax_10
+        self.sale_order.order_line[2].tax_id = self.tax_10
+        self.make_downpayment()
+        invoice = self.sale_order.invoice_ids
+        down_pay_amt = self.sale_order.amount_total / 2
+        # pylint: disable=C0326
+        expected = [
+            # keys
+            ['account_id',               'tax_ids',                       'balance',     'price_total'],
+            # base lines
+            [self.revenue_account.id,    (tax_10_pi_ba + self.tax_10).ids, -90.91,       110          ],
+            [self.revenue_account.id,    self.tax_10.ids,                  -200,         220          ],
+            [self.revenue_account.id,    self.env['account.tax'],          -100,         100          ],
+            # taxes
+            [self.revenue_account.id,    self.tax_10.ids,                  -9.09,        0            ],
+            [self.revenue_account.id,    self.env['account.tax'],          -30,          0            ],
+            # receivable
+            [self.receivable_account.id, self.env['account.tax'],          down_pay_amt, 0            ],
+        ]
+        self._assert_invoice_lines_values(invoice.line_ids, expected)
+
+    def test_tax_breakdown_with_discount(self):
+        self.sale_order.order_line[0].tax_id = self.tax_10
+        self.sale_order.order_line[1].tax_id = self.tax_10
+        self.sale_order.order_line[1].discount = 25.0
+        self.sale_order.order_line[2].tax_id = self.tax_15
+        self.make_downpayment()
+        invoice = self.sale_order.invoice_ids
+        down_pay_amt = self.sale_order.amount_total / 2
+        # pylint: disable=C0326
+        expected = [
+            # keys
+            ['account_id',               'tax_ids',               'balance',    'price_total' ],
+            # base lines
+            [self.revenue_account.id,    self.tax_10.ids,         -175,         192.5         ],
+            [self.revenue_account.id,    self.tax_15.ids,         -100,         115           ],
+            [self.revenue_account.id,    self.env['account.tax'], -100,         100           ],
+            # taxes
+            [self.revenue_account.id,    self.env['account.tax'], -17.5,        0             ],
+            [self.revenue_account.id,    self.env['account.tax'], -15,          0             ],
+            # receivable
+            [self.receivable_account.id, self.env['account.tax'], down_pay_amt, 0             ],
+        ]
+        self._assert_invoice_lines_values(invoice.line_ids, expected)
+
+    def test_tax_price_include_include_base_amount_breakdown_with_discount(self):
+        tax_10_pi_ba = self.create_tax(10, {'price_include': True, 'include_base_amount': True})
+        self.tax_10.sequence = 2
+        self.sale_order.order_line[0].tax_id = tax_10_pi_ba + self.tax_10
+        self.sale_order.order_line[0].discount = 25.0
+        self.sale_order.order_line[1].tax_id = self.tax_10
+        self.sale_order.order_line[2].tax_id = self.tax_10
+        self.make_downpayment()
+        invoice = self.sale_order.invoice_ids
+        down_pay_amt = self.sale_order.amount_total / 2
+        # pylint: disable=C0326
+        expected = [
+            # keys
+            ['account_id',               'tax_ids',                       'balance',     'price_total'],
+            # base lines
+            [self.revenue_account.id,    (tax_10_pi_ba + self.tax_10).ids, -68.18,       82.5         ],
+            [self.revenue_account.id,    self.tax_10.ids,                  -200,         220          ],
+            [self.revenue_account.id,    self.env['account.tax'],          -100,         100          ],
+            # taxes
+            [self.revenue_account.id,    self.tax_10.ids,                  -6.82,        0            ],
+            [self.revenue_account.id,    self.env['account.tax'],          -27.5,        0            ],
+            # receivable
+            [self.receivable_account.id, self.env['account.tax'],          down_pay_amt, 0            ],
+        ]
+        self._assert_invoice_lines_values(invoice.line_ids, expected)
+
+    def test_tax_fixed_amount_breakdown(self):
+        tax_10_fix_a = self.create_tax(10, {'amount_type': 'fixed', 'include_base_amount': True})
+        tax_10_fix_b = self.create_tax(10, {'amount_type': 'fixed', 'include_base_amount': True})
+        tax_10_fix_c = self.create_tax(10, {'amount_type': 'fixed'})
+        tax_10_a = self.tax_10
+        tax_10_b = self.create_tax(10)
+        tax_group_1 = self.env['account.tax'].create({
+            'name': "Tax Group",
+            'amount_type': 'group',
+            'children_tax_ids': [Command.set((tax_10_fix_a + tax_10_a + tax_10_fix_b + tax_10_b).ids)],
+            'type_tax_use': 'sale',
+        })
+        tax_group_2 = self.env['account.tax'].create({
+            'name': "Tax Group 2",
+            'amount_type': 'group',
+            'children_tax_ids': [Command.set((tax_10_fix_c + tax_10_a).ids)],
+            'type_tax_use': 'sale',
+        })
+        self.sale_order.order_line[0].tax_id = tax_group_1
+        self.sale_order.order_line[1].tax_id = tax_group_2
+        self.sale_order.order_line[2].tax_id = tax_10_a
+        self.make_downpayment()
+        invoice = self.sale_order.invoice_ids
+        down_pay_amt = self.sale_order.amount_total / 2
+        # pylint: disable=C0326
+        expected = [
+            # keys
+            ['account_id',               'tax_ids',                 'balance',    'price_total'],
+            # base lines
+            [self.revenue_account.id,    (tax_10_a + tax_10_b).ids, -110,         132          ],
+            [self.revenue_account.id,    tax_10_b.ids,              -10,          11           ],
+            [self.revenue_account.id,    tax_10_a.ids,              -200,         220          ],
+            [self.revenue_account.id,    self.env['account.tax'],   -110,         110          ],
+            # taxes
+            [self.revenue_account.id,    self.env['account.tax'],   -31,          0            ],
+            [self.revenue_account.id,    self.env['account.tax'],   -12,          0            ],
+            # receivable
+            [self.receivable_account.id, self.env['account.tax'],   down_pay_amt, 0            ],
+        ]
+        self._assert_invoice_lines_values(invoice.line_ids, expected)
+
+    def test_analytic_distribution(self):
+        analytic_plan = self.env['account.analytic.plan'].create({'name': 'Plan Test', 'company_id': False})
+        an_acc_01 = str(self.env['account.analytic.account'].create({'name': 'Account 01', 'plan_id': analytic_plan.id}).id)
+        an_acc_02 = str(self.env['account.analytic.account'].create({'name': 'Account 02', 'plan_id': analytic_plan.id}).id)
+        self.sale_order.order_line[0].tax_id = self.tax_15 + self.tax_10
+        self.sale_order.order_line[0].analytic_distribution = {an_acc_01: 100}
+        self.sale_order.order_line[1].tax_id = self.tax_10
+        self.sale_order.order_line[1].analytic_distribution = {an_acc_01: 50, an_acc_02: 50}
+        self.sale_order.order_line[2].tax_id = self.tax_10
+        self.sale_order.order_line[2].analytic_distribution = {an_acc_01: 100}
+        self.make_downpayment()
+        invoice = self.sale_order.invoice_ids
+        down_pay_amt = self.sale_order.amount_total / 2
+        # pylint: disable=C0326
+        expected = [
+            # keys
+            ['account_id',               'tax_ids',                      'balance',     'price_total', 'analytic_distribution'       ],
+            # base lines
+            [self.revenue_account.id,    (self.tax_15 + self.tax_10).ids, -100,         125,           {an_acc_01: 100}              ],
+            [self.revenue_account.id,    self.tax_10.ids,                 -100,         110,           {an_acc_01: 50, an_acc_02: 50}],
+            [self.revenue_account.id,    self.tax_10.ids,                 -100,         110,           {an_acc_01: 100}],
+            [self.revenue_account.id,    self.env['account.tax'],         -100,         100 ,          False                         ],
+            # taxes
+            [self.revenue_account.id,    self.env['account.tax'],         -30,          0,             False                         ],
+            [self.revenue_account.id,    self.env['account.tax'],         -15,          0,             False                         ],
+            # receivable
+            [self.receivable_account.id, self.env['account.tax'],         down_pay_amt, 0,             False                         ],
+        ]
+
+        self._assert_invoice_lines_values(invoice.line_ids, expected)
+
+    def test_tax_fixed_amount_analytic_distribution(self):
+        analytic_plan = self.env['account.analytic.plan'].create({'name': 'Plan Test', 'company_id': False})
+        an_acc_01 = str(self.env['account.analytic.account'].create({'name': 'Account 01', 'plan_id': analytic_plan.id}).id)
+        an_acc_02 = str(self.env['account.analytic.account'].create({'name': 'Account 02', 'plan_id': analytic_plan.id}).id)
+        tax_10_fix_a = self.create_tax(10, {'amount_type': 'fixed', 'include_base_amount': True})
+        tax_10_fix_b = self.create_tax(10, {'amount_type': 'fixed', 'include_base_amount': True})
+        tax_10_fix_c = self.create_tax(10, {'amount_type': 'fixed'})
+        tax_10_a = self.tax_10
+        tax_10_b = self.create_tax(10)
+        tax_group_1 = self.env['account.tax'].create({
+            'name': "Tax Group",
+            'amount_type': 'group',
+            'children_tax_ids': [Command.set((tax_10_fix_a + tax_10_a + tax_10_fix_b + tax_10_b).ids)],
+            'type_tax_use': 'sale',
+        })
+        tax_group_2 = self.env['account.tax'].create({
+            'name': "Tax Group 2",
+            'amount_type': 'group',
+            'children_tax_ids': [Command.set((tax_10_fix_c + tax_10_a).ids)],
+            'type_tax_use': 'sale',
+        })
+        self.sale_order.order_line[0].tax_id = tax_group_1
+        self.sale_order.order_line[0].analytic_distribution = {an_acc_01: 50, an_acc_02: 50}
+        self.sale_order.order_line[1].tax_id = tax_group_2
+        self.sale_order.order_line[2].tax_id = tax_10_a
+        self.make_downpayment()
+        invoice = self.sale_order.invoice_ids
+        down_pay_amt = self.sale_order.amount_total / 2
+        # pylint: disable=C0326
+        expected = [
+            # keys
+            ['account_id',               'tax_ids',                 'balance',    'price_total', 'analytic_distribution'],
+            # base lines
+            [self.revenue_account.id,    (tax_10_a + tax_10_b).ids, -110,         132,            {an_acc_01: 50, an_acc_02: 50}],
+            [self.revenue_account.id,    tax_10_b.ids,              -10,          11,             {an_acc_01: 50, an_acc_02: 50}],
+            [self.revenue_account.id,    tax_10_a.ids,              -200,         220,            False                         ],
+            [self.revenue_account.id,    self.env['account.tax'],   -110,         110,            False                         ],
+            # taxes
+            [self.revenue_account.id,    self.env['account.tax'],   -31,          0,              False                         ],
+            [self.revenue_account.id,    self.env['account.tax'],   -12,          0,              False                         ],
+            # receivable
+            [self.receivable_account.id, self.env['account.tax'],   down_pay_amt, 0,              False                         ],
+        ]
+        self._assert_invoice_lines_values(invoice.line_ids, expected)
diff --git a/addons/sale/views/sale_order_views.xml b/addons/sale/views/sale_order_views.xml
index 334904f79d1..b41b5c6a2fb 100644
--- a/addons/sale/views/sale_order_views.xml
+++ b/addons/sale/views/sale_order_views.xml
@@ -403,6 +403,7 @@
                                 <field name="product_uom_category_id" invisible="1"/>
                                 <field name="product_type" invisible="1"/>
                                 <field name="product_updatable" invisible="1"/>
+                                <field name="is_downpayment" invisible="1"/>
                                 <field
                                     name="product_id"
                                     attrs="{
@@ -461,6 +462,7 @@
                                         'uom': product_uom,
                                         'company_id': parent.company_id
                                     }"
+                                    attrs="{'readonly': [('is_downpayment', '==', True)]}"
                                 />
                                 <field
                                     name="qty_delivered"
@@ -468,7 +470,7 @@
                                     string="Delivered"
                                     attrs="{
                                         'column_invisible': [('parent.state', 'not in', ['sale', 'done'])],
-                                        'readonly': [('qty_delivered_method', '!=', 'manual')]
+                                        'readonly': ['|', ('qty_delivered_method', '!=', 'manual'), ('is_downpayment', '=', True)]
                                     }"
                                     optional="show"
                                 />
@@ -499,7 +501,7 @@
                                 <field
                                     name="customer_lead"
                                     optional="hide"
-                                    attrs="{'readonly': [('parent.state', 'not in', ['draft', 'sent', 'sale'])]}"
+                                    attrs="{'readonly': ['|', ('parent.state', 'not in', ['draft', 'sent', 'sale']), ('is_downpayment', '==', True)]}"
                                 />
                                 <field name="product_packaging_qty" attrs="{'invisible': ['|', ('product_id', '=', False), ('product_packaging_id', '=', False)]}" groups="product.group_stock_packaging" optional="show"/>
                                 <field name="product_packaging_id" attrs="{'invisible': [('product_id', '=', False)]}" context="{'default_product_id': product_id, 'tree_view_ref':'product.product_packaging_tree_view', 'form_view_ref':'product.product_packaging_form_view'}" groups="product.group_stock_packaging" optional="show"/>
@@ -513,7 +515,7 @@
                                     options="{'no_create': True}"
                                     domain="[('type_tax_use','=','sale'),('company_id','=',parent.company_id), ('country_id', '=', parent.tax_country_id)]"
                                     context="{'active_test': True}"
-                                    attrs="{'readonly': [('qty_invoiced', '&gt;', 0)]}"
+                                    attrs="{'readonly': ['|', ('qty_invoiced', '&gt;', 0), ('is_downpayment', '==', True)]}"
                                     optional="show"
                                 />
                                 <field name="discount" string="Disc.%" groups="product.group_discount_per_so_line" optional="show" widget="sol_discount"/>
diff --git a/addons/sale/wizard/sale_make_invoice_advance.py b/addons/sale/wizard/sale_make_invoice_advance.py
index 7dc24060f5f..206041fd791 100644
--- a/addons/sale/wizard/sale_make_invoice_advance.py
+++ b/addons/sale/wizard/sale_make_invoice_advance.py
@@ -6,7 +6,7 @@ import time
 from odoo import api, fields, models, _
 from odoo.exceptions import UserError
 from odoo.fields import Command
-from odoo.tools import float_is_zero
+from odoo.tools import frozendict
 
 
 class SaleAdvancePaymentInv(models.TransientModel):
@@ -153,10 +153,9 @@ class SaleAdvancePaymentInv(models.TransientModel):
     #=== ACTION METHODS ===#
 
     def create_invoices(self):
-        self._create_invoices(self.sale_order_ids)
-
+        invoices = self._create_invoices(self.sale_order_ids)
         if self.env.context.get('open_invoices'):
-            return self.sale_order_ids.action_view_invoice()
+            return self.sale_order_ids.action_view_invoice(invoices=invoices)
 
         return {'type': 'ir.actions.act_window_close'}
 
@@ -184,14 +183,32 @@ class SaleAdvancePaymentInv(models.TransientModel):
                     self._prepare_down_payment_section_values(order)
                 )
 
-            down_payment_so_line = self.env['sale.order.line'].create(
-                self._prepare_so_line_values(order)
+            down_payment_lines = self.env['sale.order.line'].create(
+                self._prepare_down_payment_lines_values(order)
             )
 
             invoice = self.env['account.move'].sudo().create(
-                self._prepare_invoice_values(order, down_payment_so_line)
+                self._prepare_invoice_values(order, down_payment_lines)
             ).with_user(self.env.uid)  # Unsudo the invoice after creation
 
+            # Ensure the invoice total is exactly the expected fixed amount.
+            if self.advance_payment_method == 'fixed':
+                delta_amount = (invoice.amount_total - self.fixed_amount) * (1 if invoice.is_inbound() else -1)
+                if not order.currency_id.is_zero(delta_amount):
+                    tax_line = invoice.line_ids\
+                        .filtered(lambda aml: aml.tax_line_id.amount_type not in (False, 'fixed'))[:1]
+                    receivable_line = invoice.line_ids\
+                        .filtered(lambda aml: aml.account_id.account_type == 'asset_receivable')[:1]
+                    if tax_line and receivable_line:
+                        invoice.line_ids = [
+                            Command.update(tax_line.id, {
+                                'amount_currency': tax_line.amount_currency + delta_amount,
+                            }),
+                            Command.update(receivable_line.id, {
+                                'amount_currency': receivable_line.amount_currency + delta_amount,
+                            }),
+                        ]
+
             invoice.message_post_with_source(
                 'mail.message_origin_link',
                 render_values={'self': invoice, 'origin': order},
@@ -226,52 +243,96 @@ class SaleAdvancePaymentInv(models.TransientModel):
         del context
         return so_values
 
-    def _prepare_so_line_values(self, order):
+    def _prepare_down_payment_lines_values(self, order):
+        """ Create one down payment line per tax or unique taxes combination.
+            Apply the tax(es) to their respective lines.
+
+            :param order: Order for which the down payment lines are created.
+            :return:      An array of dicts with the down payment lines values.
+        """
+        self.ensure_one()
+
+        if self.advance_payment_method == 'percentage':
+            percentage = self.amount / 100
+        else:
+            percentage = self.fixed_amount / order.amount_total
+
+        order_lines = order.order_line.filtered(lambda l: not l.display_type)
+        base_downpayment_lines_values = self._prepare_base_downpayment_line_values(order)
+
+        tax_base_line_dicts = [line._convert_to_tax_base_line_dict(
+            analytic_distribution=line.analytic_distribution) for line in order_lines]
+        computed_taxes = self.env['account.tax']._compute_taxes(
+            tax_base_line_dicts,
+            handle_price_include=False
+        )
+        down_payment_values = []
+        for line, tax_repartition in computed_taxes['base_lines_to_update']:
+            taxes = line['taxes'].flatten_taxes_hierarchy()
+            fixed_taxes = taxes.filtered(lambda tax: tax.amount_type == 'fixed')
+            down_payment_values.append([
+                taxes - fixed_taxes,
+                line['analytic_distribution'],
+                tax_repartition['price_subtotal']
+            ])
+            for fixed_tax in fixed_taxes:
+                # Fixed taxes cannot be set as taxes on down payments as they always amounts to 100%
+                # of the tax amount. Therefore fixed taxes are removed and are replace by a new line
+                # with appropriate amount, and non fixed taxes if the fixed tax affected the base of
+                # any other non fixed tax.
+                if fixed_tax.include_base_amount:
+                    pct_tax = taxes[list(taxes).index(fixed_tax) + 1:]\
+                        .filtered(lambda t: t.is_base_affected and t.amount_type != 'fixed')
+                else:
+                    pct_tax = self.env['account.tax']
+                down_payment_values.append([
+                    pct_tax,
+                    line['analytic_distribution'],
+                    line['quantity'] * fixed_tax.amount
+                ])
+
+        downpayment_line_map = {}
+        for tax_id, analytic_distribution, price_subtotal in down_payment_values:
+            grouping_key = frozendict({
+                'tax_id': tuple(sorted(tax_id.ids)),
+                'analytic_distribution': analytic_distribution,
+            })
+            downpayment_line_map.setdefault(grouping_key, {
+                **base_downpayment_lines_values,
+                **grouping_key,
+                'product_uom_qty': 0.0,
+                'price_unit': 0.0,
+            })
+            downpayment_line_map[grouping_key]['price_unit'] += \
+                order.currency_id.round(price_subtotal * percentage)
+
+        return list(downpayment_line_map.values())
+
+    def _prepare_base_downpayment_line_values(self, order):
         self.ensure_one()
-        analytic_distribution = {}
-        amount_total = sum(order.order_line.mapped("price_total"))
-        if not float_is_zero(amount_total, precision_rounding=self.currency_id.rounding):
-            for line in order.order_line:
-                distrib_dict = line.analytic_distribution or {}
-                for account, distribution in distrib_dict.items():
-                    analytic_distribution[account] = distribution * line.price_total + analytic_distribution.get(account, 0)
-            for account, distribution_amount in analytic_distribution.items():
-                analytic_distribution[account] = distribution_amount/amount_total
         context = {'lang': order.partner_id.lang}
         so_values = {
             'name': _('Down Payment: %s (Draft)', time.strftime('%m %Y')),
-            'price_unit': self._get_down_payment_amount(order),
             'product_uom_qty': 0.0,
             'order_id': order.id,
             'discount': 0.0,
             'product_id': self.product_id.id,
-            'analytic_distribution': analytic_distribution,
             'is_downpayment': True,
             'sequence': order.order_line and order.order_line[-1].sequence + 1 or 10,
         }
         del context
         return so_values
 
-    def _get_down_payment_amount(self, order):
-        self.ensure_one()
-        if self.advance_payment_method == 'percentage':
-            amount = order.amount_total * self.amount / 100
-        else:  # Fixed amount
-            amount = self.fixed_amount
-        return amount
-
-    def _prepare_invoice_values(self, order, so_line):
+    def _prepare_invoice_values(self, order, so_lines):
         self.ensure_one()
         return {
             **order._prepare_invoice(),
-            'invoice_line_ids': [
-                Command.create(
-                    so_line._prepare_invoice_line(
-                        name=self._get_down_payment_description(order),
-                        quantity=1.0,
-                    )
+            'invoice_line_ids': [Command.create(
+                line._prepare_invoice_line(
+                    name=self._get_down_payment_description(order),
+                    quantity=1.0,
                 )
-            ],
+            ) for line in so_lines],
         }
 
     def _get_down_payment_description(self, order):
@@ -282,5 +343,4 @@ class SaleAdvancePaymentInv(models.TransientModel):
         else:
             name = _('Down Payment')
         del context
-
         return name