diff --git a/addons/product/models/product_pricelist.py b/addons/product/models/product_pricelist.py
index 61d3feff07a..a8093611c29 100644
--- a/addons/product/models/product_pricelist.py
+++ b/addons/product/models/product_pricelist.py
@@ -305,6 +305,7 @@ class Pricelist(models.Model):
         return pricelist.get_products_price(
             list(pycompat.izip(**products_by_qty_by_partner)))
 
+    # DEPRECATED (Not used anymore, see d39d583b2) -> Remove me in master (saas12.3)
     def _get_partner_pricelist(self, partner_id, company_id=None):
         """ Retrieve the applicable pricelist for a given partner in a given company.
 
diff --git a/addons/website/models/ir_rule.py b/addons/website/models/ir_rule.py
index ba5e07128ee..a11ddef1e53 100644
--- a/addons/website/models/ir_rule.py
+++ b/addons/website/models/ir_rule.py
@@ -1,5 +1,6 @@
 # coding: utf-8
 from odoo import api, models
+from odoo.addons.website.models import ir_http
 
 
 class IrRule(models.Model):
@@ -8,7 +9,14 @@ class IrRule(models.Model):
     @api.model
     def _eval_context(self):
         res = super(IrRule, self)._eval_context()
-        res['website_id'] = self.env['website'].get_current_website().id
+
+        # We need is_frontend to avoid showing website's company items in backend
+        # (that could be different than current company). We can't use
+        # `get_current_website(falback=False)` as it could also return a website
+        # in backend (if domain set & match)..
+        is_frontend = ir_http.get_request_website()
+        Website = self.env['website']
+        res['website'] = is_frontend and Website.get_current_website() or Website
         return res
 
     def _compute_domain_keys(self):
diff --git a/addons/website_sale/__init__.py b/addons/website_sale/__init__.py
index 5e8764bb37f..03800bab040 100644
--- a/addons/website_sale/__init__.py
+++ b/addons/website_sale/__init__.py
@@ -1,7 +1,19 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
-
+from odoo import api, SUPERUSER_ID
 from . import controllers
 from . import models
 from . import wizard
 from . import report
+
+
+def uninstall_hook(cr, registry):
+    ''' Need to reenable the `product` pricelist multi-company rule that were
+        disabled to be 'overriden' for multi-website purpose
+    '''
+    env = api.Environment(cr, SUPERUSER_ID, {})
+    pl_rule = env.ref('product.product_pricelist_comp_rule', raise_if_not_found=False)
+    pl_item_rule = env.ref('product.product_pricelist_item_comp_rule', raise_if_not_found=False)
+    multi_company_rules = pl_rule or env['ir.rule']
+    multi_company_rules += pl_item_rule or env['ir.rule']
+    multi_company_rules.write({'active': True})
diff --git a/addons/website_sale/__manifest__.py b/addons/website_sale/__manifest__.py
index 91ce59ec5eb..b07dc32747b 100644
--- a/addons/website_sale/__manifest__.py
+++ b/addons/website_sale/__manifest__.py
@@ -30,4 +30,5 @@
     'qweb': ['static/src/xml/*.xml'],
     'installable': True,
     'application': True,
+    'uninstall_hook': 'uninstall_hook',
 }
diff --git a/addons/website_sale/models/product.py b/addons/website_sale/models/product.py
index d9c421e76b9..66f29184670 100644
--- a/addons/website_sale/models/product.py
+++ b/addons/website_sale/models/product.py
@@ -91,6 +91,17 @@ class ProductPricelist(models.Model):
             '|', ('selectable', '=', True), ('code', '!=', False),
         ]
 
+    def _get_partner_pricelist_multi(self, partner_ids, company_id=None):
+        ''' If `property_product_pricelist` is read from website, we should use
+            the website's company and not the user's one.
+            Passing a `company_id` to super will avoid using the current user's
+            company.
+        '''
+        website = ir_http.get_request_website()
+        if not company_id and website:
+            company_id = website.company_id.id
+        return super(ProductPricelist, self)._get_partner_pricelist_multi(partner_ids, company_id)
+
 
 class ProductPublicCategory(models.Model):
     _name = "product.public.category"
diff --git a/addons/website_sale/security/website_sale.xml b/addons/website_sale/security/website_sale.xml
index 5d73c4d38b7..0af26e6d7d7 100644
--- a/addons/website_sale/security/website_sale.xml
+++ b/addons/website_sale/security/website_sale.xml
@@ -52,6 +52,31 @@
         <field name="implied_ids" eval="[(4, ref('sale.group_delivery_invoice_address'))]"/>
     </record>
 
-
+    <!--
+        Multi-company/Multi-website compliant:
+        We can't add a condition on domain_force without losing `product`
+        ir.rule domain_force. It is better to disabled them to be able to
+        reenable them on `website_sale` uninstall.
+        Don't override domain_force or we will need to hardcode the original
+        domain in `uninstall_hook` rather than just reenabling records.
+    -->
+    <record id="product.product_pricelist_comp_rule" model="ir.rule">
+        <field name="active" eval="False"/>
+    </record>
+    <record id="product.product_pricelist_item_comp_rule" model="ir.rule">
+        <field name="active" eval="False"/>
+    </record>
+    <record id="product_pricelist_comp_rule" model="ir.rule">
+        <field name="name">product pricelist company rule</field>
+        <field name="model_id" ref="product.model_product_pricelist"/>
+        <field name="global" eval="True"/>
+        <field name="domain_force">[('company_id','in',(False,user.company_id.id,website.company_id.id))]</field>
+    </record>
+    <record id="product_pricelist_item_comp_rule" model="ir.rule">
+        <field name="name">product pricelist item company rule</field>
+        <field name="model_id" ref="product.model_product_pricelist_item"/>
+        <field name="global" eval="True"/>
+        <field name="domain_force">[('company_id','in',(False,user.company_id.id,website.company_id.id))]</field>
+    </record>
 
 </odoo>
diff --git a/addons/website_sale/tests/test_website_sale_pricelist.py b/addons/website_sale/tests/test_website_sale_pricelist.py
index dc04f55301a..46ae0e56a28 100644
--- a/addons/website_sale/tests/test_website_sale_pricelist.py
+++ b/addons/website_sale/tests/test_website_sale_pricelist.py
@@ -4,7 +4,7 @@ try:
     from unittest.mock import patch
 except ImportError:
     from mock import patch
-from odoo.tests.common import TransactionCase
+from odoo.tests.common import HttpCase, TransactionCase
 
 
 class TestWebsitePriceList(TransactionCase):
@@ -125,3 +125,98 @@ class TestWebsitePriceList(TransactionCase):
             pls = self.get_pl(show, current_pl, country)
             self.assertEquals(len(set(pls.mapped('name')) & set(result)), len(pls), 'Test failed for %s (%s %s vs %s %s)'
                               % (country, len(pls), pls.mapped('name'), len(result), result))
+
+
+def simulate_frontend_context(self, website_id=1):
+    # Mock this method will be enough to simulate frontend context in most methods
+    def get_request_website():
+        return self.env['website'].browse(website_id)
+    patcher = patch('odoo.addons.website.models.ir_http.get_request_website', wraps=get_request_website)
+    patcher.start()
+    self.addCleanup(patcher.stop)
+
+
+class TestWebsitePriceListMultiCompany(TransactionCase):
+    def setUp(self):
+        ''' Create a basic multi-company pricelist environment:
+        - Set up 2 companies with their own company-restricted pricelist each.
+        - Add demo user in those 2 companies
+        - For each company, add that company pricelist to the demo user partner.
+        - Set website's company to company 2
+        - Demo user will still be in company 1
+        '''
+        super(TestWebsitePriceListMultiCompany, self).setUp()
+
+        self.demo_user = self.env.ref('base.user_demo')
+
+        # Create and add demo user to 2 companies
+        self.company1 = self.demo_user.company_id
+        self.company2 = self.env['res.company'].create({'name': 'Test Company'})
+        self.demo_user.company_ids += self.company2
+        # Set company2 as current company for demo user
+        self.website = self.env['website'].browse(1)
+        self.website.company_id = self.company2
+
+        # Create a company pricelist for each company and set it to demo user
+        self.c1_pl = self.env['product.pricelist'].create({
+            'name': 'Company 1 Pricelist',
+            'company_id': self.company1.id,
+        })
+        self.c2_pl = self.env['product.pricelist'].create({
+            'name': 'Company 2 Pricelist',
+            'company_id': self.company2.id,
+            'website_id': False,
+        })
+        self.demo_user.partner_id.property_product_pricelist = self.c1_pl
+        # Switch env.user company to create ir.property in company2
+        self.env.user.company_id = self.company2
+        self.demo_user.partner_id.property_product_pricelist = self.c2_pl
+
+        # Ensure everything was done correctly
+        self.assertEqual(self.demo_user.partner_id.with_context(force_company=self.company1.id).property_product_pricelist, self.c1_pl)
+        self.assertEqual(self.demo_user.partner_id.with_context(force_company=self.company2.id).property_product_pricelist, self.c2_pl)
+        irp1 = self.env['ir.property'].search([
+            ('name', '=', 'property_product_pricelist'),
+            ('company_id', '=', self.company1.id),
+            ('res_id', '=', 'res.partner,%s' % self.demo_user.partner_id.id),
+            ('value_reference', '=', 'product.pricelist,%s' % self.c1_pl.id),
+        ])
+        irp2 = self.env['ir.property'].search([
+            ('name', '=', 'property_product_pricelist'),
+            ('company_id', '=', self.company2.id),
+            ('res_id', '=', 'res.partner,%s' % self.demo_user.partner_id.id),
+            ('value_reference', '=', 'product.pricelist,%s' % self.c2_pl.id),
+        ])
+        self.assertEqual(len(irp1 + irp2), 2, "Ensure there is an `ir.property` for demo partner for every company, and that the pricelist is the company specific one.")
+        simulate_frontend_context(self)
+        # ---------------------------------- IR.PROPERTY -------------------------------------
+        # id |            name              |     res_id    | company_id |   value_reference
+        # ------------------------------------------------------------------------------------
+        # 1  | 'property_product_pricelist' |               |      1     | product.pricelist,1
+        # 2  | 'property_product_pricelist' |               |      2     | product.pricelist,2
+        # 3  | 'property_product_pricelist' | res.partner,8 |      1     | product.pricelist,10
+        # 4  | 'property_product_pricelist' | res.partner,8 |      2     | product.pricelist,11
+
+    def test_property_product_pricelist_multi_company(self):
+        ''' Test that the `property_product_pricelist` of `res.partner` is read
+            for the company of the website and not the current user company.
+            This is the case if the user visit a website for which the company
+            is not the same as its user's company.
+
+            Here, as demo user (company1), we will visit website1 (company2).
+            It should return the ir.property for demo user for company2 and not
+            for the company1 as we should get the website's company pricelist
+            and not the demo user's current company pricelist.
+        '''
+        # First check: It should return ir.property,4 as company_id is
+        # website.company_id and not env.user.company_id
+        company_id = self.website.company_id.id
+        partner = self.demo_user.partner_id.with_context(force_company=company_id)
+        demo_pl = partner.property_product_pricelist
+        self.assertEqual(demo_pl, self.c2_pl)
+
+        # Second thing to check: It should not error in read right access error
+        # Indeed, the ir.rule for pricelists rights about company should allow to
+        # also read a pricelist from another company if that company is the one
+        # from the currently visited website.
+        self.env(user=self.env.ref('base.user_demo'))['product.pricelist'].browse(demo_pl.id).name