diff --git a/addons/barcodes/static/tests/barcode_tests.js b/addons/barcodes/static/tests/barcode_tests.js
index aefc90bb5ba..8ba4b92c3a7 100644
--- a/addons/barcodes/static/tests/barcode_tests.js
+++ b/addons/barcodes/static/tests/barcode_tests.js
@@ -8,7 +8,6 @@ var fieldRegistry = require('web.field_registry');
 var FormController = require('web.FormController');
 var FormView = require('web.FormView');
 var testUtils = require('web.test_utils');
-var NotificationService = require('web.NotificationService');
 
 var createView = testUtils.createView;
 var triggerKeypressEvent = testUtils.dom.triggerKeypressEvent;
@@ -66,11 +65,11 @@ QUnit.test('Button with barcode_trigger', async function (assert) {
             '</form>',
         res_id: 2,
         services: {
-            notification: NotificationService.extend({
+            notification: {
                 notify: function (params) {
                     assert.step(params.type);
                 }
-            }),
+            },
         },
         intercepts: {
             execute_action: function (event) {
@@ -536,11 +535,11 @@ QUnit.test('barcode_scanned only trigger error for active view', async function
         },
         res_id: 1,
         services: {
-            notification: NotificationService.extend({
+            notification: {
                 notify: function (params) {
                     assert.step(params.type);
                 }
-            }),
+            },
         },
         viewOptions: {
             mode: 'edit',
diff --git a/addons/hr/static/tests/m2x_avatar_employee_tests.js b/addons/hr/static/tests/m2x_avatar_employee_tests.js
index f1787312b87..8e943ed5f08 100644
--- a/addons/hr/static/tests/m2x_avatar_employee_tests.js
+++ b/addons/hr/static/tests/m2x_avatar_employee_tests.js
@@ -182,6 +182,21 @@ QUnit.module('hr', {}, function () {
                 return this._super(...arguments);
             },
             res_id: 1,
+            services: {
+                notification: {
+                    notify(notification) {
+                        assert.ok(
+                            true,
+                            "should display a toast notification after failing to open chat"
+                        );
+                        assert.strictEqual(
+                            notification.message,
+                            "You can only chat with employees that have a dedicated user.",
+                            "should display the correct information in the notification"
+                        );
+                    },
+                },
+            },
         });
 
         mock.intercept(form, 'call_service', (ev) => {
@@ -199,17 +214,6 @@ QUnit.module('hr', {}, function () {
             'read hr.employee.public 11',
         ]);
 
-        assert.containsOnce(
-            document.body,
-            '.toast .o_notification_content',
-            "should display a toast notification after failing to open chat"
-        );
-        assert.strictEqual(
-            document.querySelector('.o_notification_content').textContent,
-            "You can only chat with employees that have a dedicated user.",
-            "should display the correct information in the notification"
-        );
-
         form.destroy();
     });
 
@@ -339,6 +343,21 @@ QUnit.module('hr', {}, function () {
                 return this._super(...arguments);
             },
             res_id: 1,
+            services: {
+                notification: {
+                    notify(notification) {
+                        assert.ok(
+                            true,
+                            "should display a toast notification after failing to open chat"
+                        );
+                        assert.strictEqual(
+                            notification.message,
+                            "You can only chat with employees that have a dedicated user.",
+                            "should display the correct information in the notification"
+                        );
+                    },
+                },
+            },
         });
 
         mock.intercept(form, 'call_service', (ev) => {
@@ -363,16 +382,6 @@ QUnit.module('hr', {}, function () {
             "read hr.employee.public 23"
         ]);
 
-        assert.containsOnce(
-            document.body,
-            '.toast .o_notification_content',
-            "should display a toast notification after failing to open chat"
-        );
-        assert.strictEqual(
-            document.querySelector('.o_notification_content').textContent,
-            "You can only chat with employees that have a dedicated user.",
-            "should display the correct information in the notification"
-        );
         assert.containsOnce(document.body, '.o_ChatWindowHeader_name',
             "should have 1 chat window");
 
diff --git a/addons/mail/static/src/components/discuss/tests/discuss_tests.js b/addons/mail/static/src/components/discuss/tests/discuss_tests.js
index 6858974b896..0d3d8af6094 100644
--- a/addons/mail/static/src/components/discuss/tests/discuss_tests.js
+++ b/addons/mail/static/src/components/discuss/tests/discuss_tests.js
@@ -3235,6 +3235,21 @@ QUnit.test('reply to message from inbox (message linked to document)', async fun
             }
             return this._super(...arguments);
         },
+        services: {
+            notification: {
+                notify(notification) {
+                    assert.ok(
+                        true,
+                        "should display a notification after posting reply"
+                    );
+                    assert.strictEqual(
+                        notification.message,
+                        "Message posted on \"Refactoring\"",
+                        "notification should tell that message has been posted to the record 'Refactoring'"
+                    );
+                }
+            }
+        },
     });
     assert.strictEqual(
         document.querySelectorAll('.o_Message').length,
@@ -3299,15 +3314,6 @@ QUnit.test('reply to message from inbox (message linked to document)', async fun
         document.querySelector('.o_Message').classList.contains('o-selected'),
         "message should not longer be selected after posting reply"
     );
-    assert.ok(
-        document.querySelector('.o_notification'),
-        "should display a notification after posting reply"
-    );
-    assert.strictEqual(
-        document.querySelector('.o_notification_content').textContent,
-        "Message posted on \"Refactoring\"",
-        "notification should tell that message has been posted to the record 'Refactoring'"
-    );
 });
 
 QUnit.test('load recent messages from thread (already loaded some old messages)', async function (assert) {
diff --git a/addons/mail/static/src/components/messaging_menu/messaging_menu_tests.js b/addons/mail/static/src/components/messaging_menu/messaging_menu_tests.js
index 7db5fab7285..be66f735685 100644
--- a/addons/mail/static/src/components/messaging_menu/messaging_menu_tests.js
+++ b/addons/mail/static/src/components/messaging_menu/messaging_menu_tests.js
@@ -988,7 +988,7 @@ QUnit.test('rendering without OdooBot has a request (accepted)', async function
 });
 
 QUnit.test('respond to notification prompt (denied)', async function (assert) {
-    assert.expect(3);
+    assert.expect(4);
 
     await this.start({
         env: {
@@ -1001,6 +1001,15 @@ QUnit.test('respond to notification prompt (denied)', async function (assert) {
                     },
                 },
             },
+            services: {
+                notification: {
+                    notify() {
+                        assert.step(
+                            "should display a toast notification with the deny confirmation"
+                        );
+                    }
+                }
+            }
         },
     });
 
@@ -1010,11 +1019,10 @@ QUnit.test('respond to notification prompt (denied)', async function (assert) {
     await afterNextRender(() =>
         document.querySelector('.o_NotificationRequest').click()
     );
-    assert.containsOnce(
-        document.body,
-        '.toast .o_notification_content',
-        "should display a toast notification with the deny confirmation"
-    );
+    assert.verifySteps([
+        "should display a toast notification with the deny confirmation",
+    ]);
+
     assert.containsNone(
         document.body,
         '.o_MessagingMenu_counter',
diff --git a/addons/mail/static/src/models/messaging/messaging_tests.js b/addons/mail/static/src/models/messaging/messaging_tests.js
index 92b3e32fd63..5d3dccf5846 100644
--- a/addons/mail/static/src/models/messaging/messaging_tests.js
+++ b/addons/mail/static/src/models/messaging/messaging_tests.js
@@ -26,38 +26,50 @@ QUnit.test('openChat: display notification for partner without user', async func
     assert.expect(2);
 
     this.data['res.partner'].records.push({ id: 14 });
-    await this.start();
+    await this.start({
+        services: {
+            notification: {
+                notify(notification) {
+                    assert.ok(
+                        true,
+                        "should display a toast notification after failing to open chat"
+                    );
+                    assert.strictEqual(
+                        notification.message,
+                        "You can only chat with partners that have a dedicated user.",
+                        "should display the correct information in the notification"
+                    );
+                },
+            },
+        },
+    });
 
     await this.env.messaging.openChat({ partnerId: 14 });
-    assert.containsOnce(
-        document.body,
-        '.toast .o_notification_content',
-        "should display a toast notification after failing to open chat"
-    );
-    assert.strictEqual(
-        document.querySelector('.o_notification_content').textContent,
-        "You can only chat with partners that have a dedicated user.",
-        "should display the correct information in the notification"
-    );
 });
 
 QUnit.test('openChat: display notification for wrong user', async function (assert) {
     assert.expect(2);
 
-    await this.start();
+    await this.start({
+        services: {
+            notification: {
+                notify(notification) {
+                    assert.ok(
+                        true,
+                        "should display a toast notification after failing to open chat"
+                    );
+                    assert.strictEqual(
+                        notification.message,
+                        "You can only chat with existing users.",
+                        "should display the correct information in the notification"
+                    );
+                },
+            },
+        },
+    });
 
     // user id not in this.data
     await this.env.messaging.openChat({ userId: 14 });
-    assert.containsOnce(
-        document.body,
-        '.toast .o_notification_content',
-        "should display a toast notification after failing to open chat"
-    );
-    assert.strictEqual(
-        document.querySelector('.o_notification_content').textContent,
-        "You can only chat with existing users.",
-        "should display the correct information in the notification"
-    );
 });
 
 QUnit.test('openChat: open new chat for user', async function (assert) {
diff --git a/addons/mail/static/src/utils/test_utils.js b/addons/mail/static/src/utils/test_utils.js
index cc288f2f49f..a5c1d6b1770 100644
--- a/addons/mail/static/src/utils/test_utils.js
+++ b/addons/mail/static/src/utils/test_utils.js
@@ -15,7 +15,6 @@ import MessagingMenuWidget from '@mail/widgets/messaging_menu/messaging_menu';
 import { MockModels } from '@mail/../tests/helpers/mock_models';
 
 import AbstractStorageService from 'web.AbstractStorageService';
-import NotificationService from 'web.NotificationService';
 import RamStorage from 'web.RamStorage';
 import {
     createView,
@@ -523,7 +522,6 @@ async function start(param0 = {}) {
             _listenHomeMenu: () => {},
         }),
         local_storage: AbstractStorageService.extend({ storage: new RamStorage() }),
-        notification: NotificationService.extend(),
     }, param0.services);
 
     const kwargs = Object.assign({}, param0, {
diff --git a/addons/partner_autocomplete/static/tests/partner_autocomplete_tests.js b/addons/partner_autocomplete/static/tests/partner_autocomplete_tests.js
index af7ee95e274..00a4e8aa03e 100644
--- a/addons/partner_autocomplete/static/tests/partner_autocomplete_tests.js
+++ b/addons/partner_autocomplete/static/tests/partner_autocomplete_tests.js
@@ -6,7 +6,6 @@ odoo.define('partner_autocomplete.tests', function (require) {
     var testUtils = require("web.test_utils");
     var AutocompleteField = require('partner.autocomplete.fieldchar');
     var PartnerField = require('partner.autocomplete.many2one');
-    var NotificationService = require('web.NotificationService');
 
     var createView = testUtils.createView;
 
@@ -377,7 +376,7 @@ odoo.define('partner_autocomplete.tests', function (require) {
     });
 
     QUnit.test("Partner autocomplete : Notify not enough credits", async function (assert) {
-        assert.expect(1);
+        assert.expect(2);
 
         enrichData = {
             error: true,
@@ -394,7 +393,12 @@ odoo.define('partner_autocomplete.tests', function (require) {
                 '<field name="name" widget="field_partner_autocomplete"/>' +
                 '</form>',
             services: {
-                notification: NotificationService,
+                notification: {
+                    notify(notification) {
+                        assert.equal(notification.type, "warning");
+                        assert.equal(notification.className, "o_partner_autocomplete_test_notify");
+                    },
+                },
             },
             mockRPC: function (route, args) {
                 if (args.method === "get_credits_url"){
@@ -413,9 +417,6 @@ odoo.define('partner_autocomplete.tests', function (require) {
             var $dropdown = form.$(".o_field_partner_autocomplete .dropdown-menu:visible");
             await testUtils.dom.click($dropdown.find("a").first());
 
-            var $notify = $(".o_partner_autocomplete_test_notify");
-            assert.isVisible($notify, "there should be an 'Insufficient Credit' notification");
-
             form.destroy();
     });
 });
diff --git a/addons/web/static/tests/legacy/fields/relational_fields/field_one2many_tests.js b/addons/web/static/tests/legacy/fields/relational_fields/field_one2many_tests.js
index aea12de8184..c25a871e586 100644
--- a/addons/web/static/tests/legacy/fields/relational_fields/field_one2many_tests.js
+++ b/addons/web/static/tests/legacy/fields/relational_fields/field_one2many_tests.js
@@ -6,11 +6,9 @@ var AbstractField = require('web.AbstractField');
 var AbstractStorageService = require('web.AbstractStorageService');
 const ControlPanel = require('web.ControlPanel');
 const fieldRegistry = require('web.field_registry');
-var FormController = require('web.FormController');
 var FormView = require('web.FormView');
 var KanbanRecord = require('web.KanbanRecord');
 var ListRenderer = require('web.ListRenderer');
-var NotificationService = require('web.NotificationService');
 var RamStorage = require('web.RamStorage');
 var relationalFields = require('web.relational_fields');
 var testUtils = require('web.test_utils');
@@ -5832,11 +5830,11 @@ QUnit.module('fields', {}, function () {
                 },
                 res_id: 1,
                 services: {
-                    notification: NotificationService.extend({
+                    notification: {
                         notify: function (params) {
                             assert.step(params.type);
                         }
-                    }),
+                    },
                 },
                 intercepts: {
                     execute_action: function (event) {
diff --git a/addons/web/static/tests/legacy/views/form_tests.js b/addons/web/static/tests/legacy/views/form_tests.js
index cf79de76a93..395b290b4c3 100644
--- a/addons/web/static/tests/legacy/views/form_tests.js
+++ b/addons/web/static/tests/legacy/views/form_tests.js
@@ -11,7 +11,6 @@ const fieldRegistryOwl = require('web.field_registry_owl');
 const FormRenderer = require('web.FormRenderer');
 var FormView = require('web.FormView');
 var mixins = require('web.mixins');
-var NotificationService = require('web.NotificationService');
 var pyUtils = require('web.py_utils');
 var RamStorage = require('web.RamStorage');
 var testUtils = require('web.test_utils');
@@ -3599,7 +3598,7 @@ QUnit.module('Views', {
                         '<group><field name="foo"/></group>' +
                 '</form>',
             services: {
-                notification: NotificationService.extend({
+                notification: {
                     notify: function (params) {
                         if (params.type !== 'danger') {
                             return;
@@ -3609,7 +3608,7 @@ QUnit.module('Views', {
                         assert.strictEqual(params.message, '<ul><li>Foo</li></ul>',
                             "should have a warning with correct message");
                     }
-                }),
+                },
             },
         });
 
@@ -6140,11 +6139,11 @@ QUnit.module('Views', {
                 return result;
             },
             services: {
-                notification: NotificationService.extend({
+                notification: {
                     notify: function (params) {
                         assert.step(params.type);
                     }
-                }),
+                },
             },
         });
 
diff --git a/addons/web/static/tests/legacy/views/list_tests.js b/addons/web/static/tests/legacy/views/list_tests.js
index 6ddcb1862a3..e3fe29ae32a 100644
--- a/addons/web/static/tests/legacy/views/list_tests.js
+++ b/addons/web/static/tests/legacy/views/list_tests.js
@@ -13,7 +13,6 @@ var FormView = require('web.FormView');
 var ListRenderer = require('web.ListRenderer');
 var ListView = require('web.ListView');
 var mixins = require('web.mixins');
-var NotificationService = require('web.NotificationService');
 var RamStorage = require('web.RamStorage');
 var testUtils = require('web.test_utils');
 const { patch, unpatch } = require('web.utils');
@@ -3463,11 +3462,11 @@ QUnit.module('Views', {
                 return this._super.apply(this, arguments);
             },
             services: {
-                notification: NotificationService.extend({
+                notification: {
                     notify: function () {
                         throw new Error('should not display a notification');
                     },
-                }),
+                },
             },
             viewOptions: {
                 hasActionMenus: true,
@@ -3511,11 +3510,11 @@ QUnit.module('Views', {
                 return this._super.apply(this, arguments);
             },
             services: {
-                notification: NotificationService.extend({
+                notification: {
                     notify: function () {
                         assert.step('notify');
                     },
-                }),
+                },
             },
             session: {
                 active_ids_limit: 4,
@@ -3613,11 +3612,11 @@ QUnit.module('Views', {
                 return this._super.apply(this, arguments);
             },
             services: {
-                notification: NotificationService.extend({
+                notification: {
                     notify: function () {
                         throw new Error('should not display a notification');
                     },
-                }),
+                },
             },
             viewOptions: {
                 hasActionMenus: true,
@@ -3664,11 +3663,11 @@ QUnit.module('Views', {
                 return this._super.apply(this, arguments);
             },
             services: {
-                notification: NotificationService.extend({
+                notification: {
                     notify: function () {
                         assert.step('notify');
                     },
-                }),
+                },
             },
             session: {
                 active_ids_limit: 4,
@@ -5771,13 +5770,13 @@ QUnit.module('Views', {
                     '<field name="bar"/>' +
                 '</tree>',
             services: {
-                notification: NotificationService.extend({
+                notification: {
                     notify: function (params) {
                         if (params.type === 'danger') {
                             warnings++;
                         }
                     }
-                }),
+                },
             },
         });