diff --git a/addons/account/models/account_invoice.py b/addons/account/models/account_invoice.py
index 56f1e9c910e..f4fe6810f44 100644
--- a/addons/account/models/account_invoice.py
+++ b/addons/account/models/account_invoice.py
@@ -302,6 +302,7 @@ class AccountInvoice(models.Model):
         readonly=True, index=True, ondelete='restrict', copy=False,
         help="Link to the automatically generated Journal Items.")
 
+    amount_by_group = fields.Binary(string="Taxe amount by group", compute='_amount_by_group', help="type: [(name, amount, base, formated amount, formated base)]")
     amount_untaxed = fields.Monetary(string='Untaxed Amount',
         store=True, readonly=True, compute='_compute_amount', track_visibility='always')
     amount_untaxed_signed = fields.Monetary(string='Untaxed Amount in Company Currency', currency_field='company_currency_id',
@@ -1488,22 +1489,21 @@ class AccountInvoice(models.Model):
             return 'account.mt_invoice_created'
         return super(AccountInvoice, self)._track_subtype(init_values)
 
-    @api.multi
-    def _get_tax_amount_by_group(self):
-        self.ensure_one()
-        currency = self.currency_id or self.company_id.currency_id
-        fmt = partial(formatLang, self.with_context(lang=self.partner_id.lang).env, currency_obj=currency)
-        res = {}
-        for line in self.tax_line_ids:
-            res.setdefault(line.tax_id.tax_group_id, {'base': 0.0, 'amount': 0.0})
-            res[line.tax_id.tax_group_id]['amount'] += line.amount
-            res[line.tax_id.tax_group_id]['base'] += line.base
-        res = sorted(res.items(), key=lambda l: l[0].sequence)
-        res = [(
-            r[0].name, r[1]['amount'], r[1]['base'],
-            fmt(r[1]['amount']), fmt(r[1]['base']),
-        ) for r in res]
-        return res
+    def _amount_by_group(self):
+        for invoice in self:
+            currency = invoice.currency_id or invoice.company_id.currency_id
+            fmt = partial(formatLang, invoice.with_context(lang=invoice.partner_id.lang).env, currency_obj=currency)
+            res = {}
+            for line in invoice.tax_line_ids:
+                res.setdefault(line.tax_id.tax_group_id, {'base': 0.0, 'amount': 0.0})
+                res[line.tax_id.tax_group_id]['amount'] += line.amount
+                res[line.tax_id.tax_group_id]['base'] += line.base
+            res = sorted(res.items(), key=lambda l: l[0].sequence)
+            invoice.amount_by_group = [(
+                r[0].name, r[1]['amount'], r[1]['base'],
+                fmt(r[1]['amount']), fmt(r[1]['base']),
+                len(res),
+            ) for r in res]
 
 
 class AccountInvoiceLine(models.Model):
@@ -1538,6 +1538,10 @@ class AccountInvoiceLine(models.Model):
                 return journal.default_credit_account_id.id
             return journal.default_debit_account_id.id
 
+    def _get_price_tax(self):
+        for l in self:
+            l.price_tax = l.price_total - l.price_subtotal
+
     name = fields.Text(string='Description', required=True)
     origin = fields.Char(string='Source Document',
         help="Reference of the document that produced this invoice.")
@@ -1561,6 +1565,7 @@ class AccountInvoiceLine(models.Model):
     price_subtotal_signed = fields.Monetary(string='Amount Signed', currency_field='company_currency_id',
         store=True, readonly=True, compute='_compute_price',
         help="Total amount in the currency of the company, negative for credit note.")
+    price_tax = fields.Monetary(string='Tax Amount', compute='_get_price_tax', store=False)
     quantity = fields.Float(string='Quantity', digits=dp.get_precision('Product Unit of Measure'),
         required=True, default=1)
     discount = fields.Float(string='Discount (%)', digits=dp.get_precision('Discount'),
diff --git a/addons/account/views/report_invoice.xml b/addons/account/views/report_invoice.xml
index 31e0417b5a2..fae65fc1c29 100644
--- a/addons/account/views/report_invoice.xml
+++ b/addons/account/views/report_invoice.xml
@@ -107,11 +107,7 @@
                                             <span t-esc="', '.join(map(lambda x: (x.description or x.name), line.invoice_line_tax_ids))"/>
                                         </td>
                                         <td t-if="display_taxamount and type_is_out" class="text-right d-none d-md-table-cell">
-                                            <t t-set="taxes"
-                                               t-value="line.invoice_line_tax_ids.compute_all(line.price_unit, line.currency_id, line.quantity)"/>
-                                            <t t-set="tax_amount"
-                                               t-value="taxes and (taxes['total_included'] - taxes['base']) or 0.0"/>
-                                            <span t-esc="tax_amount" t-options='{"widget": "monetary", "display_currency": o.currency_id}'/>
+                                            <span t-esc="line.price_tax" t-options='{"widget": "monetary", "display_currency": o.currency_id}'/>
                                         </td>
                                         <td class="text-right">
                                             <span
@@ -164,7 +160,7 @@
                                             <span t-field="o.amount_untaxed" t-options='{"widget": "monetary", "display_currency": o.currency_id}'/>
                                         </td>
                                     </tr>
-                                    <t t-foreach="o._get_tax_amount_by_group()" t-as="amount_by_group">
+                                    <t t-foreach="o.amount_by_group" t-as="amount_by_group">
                                         <tr style="border-bottom:1px solid #dddddd;">
                                             <t t-if="len(o.tax_line_ids) == 1 and o.amount_untaxed == amount_by_group[2]">
                                                 <td>
diff --git a/addons/sale/models/sale.py b/addons/sale/models/sale.py
index d3ac169e17b..2d6fa9e9cb1 100644
--- a/addons/sale/models/sale.py
+++ b/addons/sale/models/sale.py
@@ -4,9 +4,12 @@
 import uuid
 
 from datetime import datetime, timedelta
+from functools import partial
+from itertools import groupby
 
 from odoo import api, fields, models, _
 from odoo.exceptions import UserError, AccessError
+from odoo.tools.misc import formatLang
 from odoo.osv import expression
 from odoo.tools import float_is_zero, float_compare
 
@@ -146,6 +149,7 @@ class SaleOrder(models.Model):
     note = fields.Text('Terms and conditions', default=_default_note)
 
     amount_untaxed = fields.Monetary(string='Untaxed Amount', store=True, readonly=True, compute='_amount_all', track_visibility='onchange', track_sequence=5)
+    amount_by_group = fields.Binary(string="Taxe amount by group", compute='_amount_by_group', help="type: [(name, amount, base, formated amount, formated base)]")
     amount_tax = fields.Monetary(string='Taxes', store=True, readonly=True, compute='_amount_all')
     amount_total = fields.Monetary(string='Total', store=True, readonly=True, compute='_amount_all', track_visibility='always', track_sequence=6)
 
@@ -617,23 +621,48 @@ class SaleOrder(models.Model):
             })
             order.analytic_account_id = analytic
 
-    @api.multi
-    def _get_tax_amount_by_group(self):
+    def _amount_by_group(self):
+        for order in self:
+            currency = order.currency_id or order.company_id.currency_id
+            fmt = partial(formatLang, self.with_context(lang=order.partner_id.lang).env, currency_obj=currency)
+            res = {}
+            for line in self.order_line:
+                price_reduce = line.price_unit * (1.0 - line.discount / 100.0)
+                taxes = line.tax_id.compute_all(price_reduce, quantity=line.product_uom_qty, product=line.product_id, partner=self.partner_shipping_id)['taxes']
+                for tax in line.tax_id:
+                    group = tax.tax_group_id
+                    res.setdefault(group, {'amount': 0.0, 'base': 0.0})
+                    for t in taxes:
+                        if t['id'] == tax.id or t['id'] in tax.children_tax_ids.ids:
+                            res[group]['amount'] += t['amount']
+                            res[group]['base'] += t['base']
+            res = sorted(res.items(), key=lambda l: l[0].sequence)
+            order.amount_by_group = [(
+                l[0].name, l[1]['amount'], l[1]['base'],
+                fmt(l[1]['amount']), fmt(l[1]['base']),
+                len(res),
+            ) for l in res]
+
+    def order_lines_layouted(self):
+        """
+        Returns this order lines classified by sale_layout_category and separated in
+        pages according to the category pagebreaks. Used to render the report.
+        """
         self.ensure_one()
-        res = {}
-        for line in self.order_line:
-            price_reduce = line.price_unit * (1.0 - line.discount / 100.0)
-            taxes = line.tax_id.compute_all(price_reduce, quantity=line.product_uom_qty, product=line.product_id, partner=self.partner_shipping_id)['taxes']
-            for tax in line.tax_id:
-                group = tax.tax_group_id
-                res.setdefault(group, {'amount': 0.0, 'base': 0.0})
-                for t in taxes:
-                    if t['id'] == tax.id or t['id'] in tax.children_tax_ids.ids:
-                        res[group]['amount'] += t['amount']
-                        res[group]['base'] += t['base']
-        res = sorted(res.items(), key=lambda l: l[0].sequence)
-        res = [(l[0].name, l[1]['amount'], l[1]['base'], len(res)) for l in res]
-        return res
+        report_pages = [[]]
+        for category, lines in groupby(self.order_line, lambda l: l.layout_category_id):
+            # If last added category induced a pagebreak, this one will be on a new page
+            if report_pages[-1] and report_pages[-1][-1]['pagebreak']:
+                report_pages.append([])
+            # Append category to current report page
+            report_pages[-1].append({
+                'name': category and category.name or _('Uncategorized'),
+                'subtotal': category and category.subtotal,
+                'pagebreak': category and category.pagebreak,
+                'lines': list(lines)
+            })
+
+        return report_pages
 
     def get_portal_confirmation_action(self):
         if self.company_id.portal_confirmation_sign and not self.signature:
diff --git a/addons/sale/report/sale_report_templates.xml b/addons/sale/report/sale_report_templates.xml
index ef7916213fb..23ec95c586d 100644
--- a/addons/sale/report/sale_report_templates.xml
+++ b/addons/sale/report/sale_report_templates.xml
@@ -175,7 +175,7 @@
                                         t-options='{"widget": "monetary", "display_currency": doc.pricelist_id.currency_id}'/>
                                 </td>
                             </tr>
-                            <t t-foreach="doc._get_tax_amount_by_group()" t-as="amount_by_group">
+                            <t t-foreach="doc.amount_by_group" t-as="amount_by_group">
                                 <tr style="border-bottom:1px solid #dddddd;">
                                     <t t-if="amount_by_group[3] == 1 and doc.amount_untaxed == amount_by_group[2]">
                                         <td>
diff --git a/addons/sale/views/sale_portal_templates.xml b/addons/sale/views/sale_portal_templates.xml
index a48cfe4bdf5..b71f4ae9711 100644
--- a/addons/sale/views/sale_portal_templates.xml
+++ b/addons/sale/views/sale_portal_templates.xml
@@ -326,7 +326,7 @@
                       </div>
                   </div>
                   <div class="row mb4">
-                    <t t-set="tax_groups" t-value="order._get_tax_amount_by_group()"/>
+                    <t t-set="tax_groups" t-value="order.amount_by_group"/>
                     <t t-foreach="tax_groups" t-as="amount_by_group">
                         <t t-if="len(tax_groups) == 1 and order.amount_untaxed == amount_by_group[2]">
                             <div class="col-lg-9 col-8 text-right"><span t-esc="amount_by_group[0]"/></div>
diff --git a/addons/website_quote/views/website_quote_templates.xml b/addons/website_quote/views/website_quote_templates.xml
index 9b73aaf69f4..28851eb32de 100644
--- a/addons/website_quote/views/website_quote_templates.xml
+++ b/addons/website_quote/views/website_quote_templates.xml
@@ -140,7 +140,7 @@
                         />
                     </td>
                 </tr>
-                <t t-foreach="quotation._get_tax_amount_by_group()" t-as="amount_by_group">
+                <t t-foreach="quotation.amount_by_group" t-as="amount_by_group">
                     <tr style="border-bottom:1px solid #dddddd;">
                       <t t-if="amount_by_group[3] == 1 and quotation.amount_untaxed == amount_by_group[2]">
                         <td>