diff --git a/addons/mail/static/src/components/chat_window/chat_window.js b/addons/mail/static/src/components/chat_window/chat_window.js
index e25598b1879..76114f7e831 100644
--- a/addons/mail/static/src/components/chat_window/chat_window.js
+++ b/addons/mail/static/src/components/chat_window/chat_window.js
@@ -293,6 +293,10 @@ class ChatWindow extends Component {
          * CTRL-C & CTRL-V when on the home menu.
          */
         ev.stopPropagation();
+        if (!this.chatWindow) {
+            // prevent crash during delete
+            return;
+        }
         switch (ev.key) {
             case 'Tab':
                 ev.preventDefault();
diff --git a/addons/mail/static/src/components/message/message_tests.js b/addons/mail/static/src/components/message/message_tests.js
index ce01dab0c7c..f7b4210f128 100644
--- a/addons/mail/static/src/components/message/message_tests.js
+++ b/addons/mail/static/src/components/message/message_tests.js
@@ -346,7 +346,7 @@ QUnit.test("'channel_fetch' notification received is correctly handled", async f
     assert.expect(3);
 
     await this.start();
-    const currentPartner = this.env.models['mail.partner'].create({
+    const currentPartner = this.env.models['mail.partner'].insert({
         id: this.env.session.partner_id,
         display_name: "Demo User",
     });
@@ -402,7 +402,7 @@ QUnit.test("'channel_seen' notification received is correctly handled", async fu
     assert.expect(3);
 
     await this.start();
-    const currentPartner = this.env.models['mail.partner'].create({
+    const currentPartner = this.env.models['mail.partner'].insert({
         id: this.env.session.partner_id,
         display_name: "Demo User",
     });
@@ -457,7 +457,7 @@ QUnit.test("'channel_fetch' notification then 'channel_seen' received  are corre
     assert.expect(4);
 
     await this.start();
-    const currentPartner = this.env.models['mail.partner'].create({
+    const currentPartner = this.env.models['mail.partner'].insert({
         id: this.env.session.partner_id,
         display_name: "Demo User",
     });
@@ -537,10 +537,12 @@ QUnit.test('do not show messaging seen indicator if not authored by me', async f
         id: 11,
         partnerSeenInfos: [['create', [
             {
+                id: this.env.session.partner_id,
                 lastFetchedMessage: [['insert', {id: 100}]],
                 partner: [['insert', {id: this.env.session.partner_id}]],
             },
             {
+                id: 100,
                 lastFetchedMessage: [['insert', {id: 100}]],
                 partner: [['link', author]],
             },
@@ -548,7 +550,7 @@ QUnit.test('do not show messaging seen indicator if not authored by me', async f
         model: 'mail.channel',
     });
     const threadViewer = this.env.models['mail.thread_viewer'].create({ thread: [['link', thread]] });
-    const message = this.env.models['mail.message'].create({
+    const message = this.env.models['mail.message'].insert({
         author: [['link', author]],
         body: "<p>Test</p>",
         id: 100,
@@ -572,7 +574,7 @@ QUnit.test('do not show messaging seen indicator if before last seen by all mess
     assert.expect(3);
 
     await this.start();
-    const currentPartner = this.env.models['mail.partner'].create({
+    const currentPartner = this.env.models['mail.partner'].insert({
         id: this.env.session.partner_id,
         display_name: "Demo User",
     });
@@ -591,7 +593,7 @@ QUnit.test('do not show messaging seen indicator if before last seen by all mess
         id: 100,
         originThread: [['link', thread]],
     });
-    const message = this.env.models['mail.message'].create({
+    const message = this.env.models['mail.message'].insert({
         author: [['link', currentPartner]],
         body: "<p>Test</p>",
         id: 99,
@@ -600,10 +602,12 @@ QUnit.test('do not show messaging seen indicator if before last seen by all mess
     thread.update({
        partnerSeenInfos: [['create', [
             {
+                id: currentPartner.id,
                 lastSeenMessage: [['link', lastSeenMessage]],
                 partner: [['link', currentPartner]],
             },
             {
+                id: 100,
                 lastSeenMessage: [['link', lastSeenMessage]],
                 partner: [['insert', {id: 100}]],
             },
@@ -632,18 +636,19 @@ QUnit.test('only show messaging seen indicator if authored by me, after last see
     assert.expect(3);
 
     await this.start();
-    const currentPartner = this.env.models['mail.partner'].create({
+    const currentPartner = this.env.models['mail.partner'].insert({
         id: this.env.session.partner_id,
-        display_name: "Demo User"
     });
     const thread = this.env.models['mail.thread'].create({
         id: 11,
         partnerSeenInfos: [['create', [
             {
+                id: currentPartner.id,
                 lastSeenMessage: [['insert', {id: 100}]],
                 partner: [['link', currentPartner]],
             },
             {
+                id: 100,
                 partner: [['insert', {id: 100}]],
                 lastFetchedMessage: [['insert', {id: 100}]],
                 lastSeenMessage: [['insert', {id: 99}]],
@@ -656,7 +661,7 @@ QUnit.test('only show messaging seen indicator if authored by me, after last see
         model: 'mail.channel',
     });
     const threadViewer = this.env.models['mail.thread_viewer'].create({ thread: [['link', thread]] });
-    const message = this.env.models['mail.message'].create({
+    const message = this.env.models['mail.message'].insert({
         author: [['link', currentPartner]],
         body: "<p>Test</p>",
         id: 100,
@@ -677,8 +682,8 @@ QUnit.test('only show messaging seen indicator if authored by me, after last see
     assert.containsN(
         document.body,
         '.o_MessageSeenIndicator_icon',
-        2,
-        "message component should have two checks (V)"
+        1,
+        "message component should have one check (V) because the message was fetched by everyone but no other member than author has seen the message"
     );
 });
 
diff --git a/addons/mail/static/src/components/message_seen_indicator/message_seen_indicator_tests.js b/addons/mail/static/src/components/message_seen_indicator/message_seen_indicator_tests.js
index ece69bbdad9..3f95a1d5407 100644
--- a/addons/mail/static/src/components/message_seen_indicator/message_seen_indicator_tests.js
+++ b/addons/mail/static/src/components/message_seen_indicator/message_seen_indicator_tests.js
@@ -60,10 +60,12 @@ QUnit.test('rendering when just one has received the message', async function (a
         model: 'mail.channel',
         partnerSeenInfos: [['create', [
             {
+                id: 10,
                 partner: [['create', {id: 10}]],
                 lastFetchedMessage: [['insert', {id: 100}]]
             },
             {
+                id: 100,
                 partner: [['create', {id: 100}]],
             },
         ]]],
@@ -72,7 +74,7 @@ QUnit.test('rendering when just one has received the message', async function (a
             message: [['insert', {id: 100}]],
         }]],
     });
-    const message = this.env.models['mail.message'].create({
+    const message = this.env.models['mail.message'].insert({
         author: [['insert', { id: this.env.session.partner_id, display_name: "Demo User" }]],
         body: "<p>Test</p>",
         id: 100,
@@ -105,10 +107,12 @@ QUnit.test('rendering when everyone have received the message', async function (
         model: 'mail.channel',
         partnerSeenInfos: [['create', [
             {
+                id: 10,
                 partner: [['create', {id: 10}]],
                 lastFetchedMessage: [['insert', {id: 100}]],
             },
             {
+                id: 100,
                 partner: [['create', {id: 100}]],
                 lastFetchedMessage: [['insert', {id: 99}]],
             },
@@ -118,7 +122,7 @@ QUnit.test('rendering when everyone have received the message', async function (
             message: [['insert', {id: 100}]],
         }]],
     });
-    const message = this.env.models['mail.message'].create({
+    const message = this.env.models['mail.message'].insert({
         author: [['insert', { id: this.env.session.partner_id, display_name: "Demo User" }]],
         body: "<p>Test</p>",
         id: 100,
@@ -151,11 +155,13 @@ QUnit.test('rendering when just one has seen the message', async function (asser
         model: 'mail.channel',
         partnerSeenInfos: [['create', [
             {
+                id: 10,
                 partner: [['create', {id: 10}]],
                 lastFetchedMessage: [['insert', {id: 100}]],
                 lastSeenMessage: [['insert', {id: 100}]],
             },
             {
+                id: 100,
                 partner: [['create', {id: 100}]],
                 lastFetchedMessage: [['insert', {id: 99}]],
             },
@@ -165,7 +171,7 @@ QUnit.test('rendering when just one has seen the message', async function (asser
             message: [['insert', {id: 100}]],
         }]],
     });
-    const message = this.env.models['mail.message'].create({
+    const message = this.env.models['mail.message'].insert({
         author: [['insert', { id: this.env.session.partner_id, display_name: "Demo User" }]],
         body: "<p>Test</p>",
         id: 100,
@@ -199,11 +205,13 @@ QUnit.test('rendering when just one has seen & received the message', async func
         model: 'mail.channel',
         partnerSeenInfos: [['create', [
             {
+                id: 10,
                 partner: [['create', {id: 10}]],
                 lastFetchedMessage: [['insert', {id: 100}]],
                 lastSeenMessage: [['insert', {id: 100}]],
             },
             {
+                id: 100,
                 partner: [['create', {id: 100}]],
             },
         ]]],
@@ -212,7 +220,7 @@ QUnit.test('rendering when just one has seen & received the message', async func
             message: [['insert', {id: 100}]],
         }]],
     });
-    const message = this.env.models['mail.message'].create({
+    const message = this.env.models['mail.message'].insert({
         author: [['insert', { id: this.env.session.partner_id, display_name: "Demo User" }]],
         body: "<p>Test</p>",
         id: 100,
@@ -246,11 +254,13 @@ QUnit.test('rendering when just everyone has seen the message', async function (
         model: 'mail.channel',
         partnerSeenInfos: [['create', [
             {
+                id: 10,
                 partner: [['create', {id: 10}]],
                 lastFetchedMessage: [['insert', {id: 100}]],
                 lastSeenMessage: [['insert', {id: 100}]],
             },
             {
+                id: 100,
                 partner: [['create', {id: 100}]],
                 lastFetchedMessage: [['insert', {id: 100}]],
                 lastSeenMessage: [['insert', {id: 100}]],
@@ -261,7 +271,7 @@ QUnit.test('rendering when just everyone has seen the message', async function (
             message: [['insert', {id: 100}]],
         }]],
     });
-    const message = this.env.models['mail.message'].create({
+    const message = this.env.models['mail.message'].insert({
         author: [['insert', { id: this.env.session.partner_id, display_name: "Demo User" }]],
         body: "<p>Test</p>",
         id: 100,
diff --git a/addons/mail/static/src/model/model_manager.js b/addons/mail/static/src/model/model_manager.js
index 815a3c05409..91bd65c58bc 100644
--- a/addons/mail/static/src/model/model_manager.js
+++ b/addons/mail/static/src/model/model_manager.js
@@ -126,7 +126,10 @@ class ModelManager {
             const res = dataList.map(data => {
                 const record = new Model({ valid: true });
                 Object.defineProperty(record, 'env', { get: () => Model.env });
-                record.localId = record._createRecordLocalId(data);
+                record.localId = Model._createRecordLocalId(data);
+                if (Model.get(record.localId)) {
+                    throw Error(`A record already exists for model "${Model.modelName}" with localId "${record.localId}".`);
+                }
                 // Contains field values of record.
                 record.__values = {};
                 // Contains revNumber of record for checking record update in useStore.
@@ -207,7 +210,6 @@ class ModelManager {
             }
             record.update(data);
             delete this._records[record.localId];
-            delete this.env.store.state[record.localId];
         });
     }
 
@@ -277,7 +279,8 @@ class ModelManager {
             const isMulti = typeof data[Symbol.iterator] === 'function';
             const dataList = isMulti ? data : [data];
             const res = dataList.map(data => {
-                let record = Model.find(Model._findFunctionFromData(data));
+                const localId = Model._createRecordLocalId(data);
+                let record = Model.get(localId);
                 if (!record) {
                     record = Model.create(data);
                 } else {
diff --git a/addons/mail/static/src/models/activity/activity.js b/addons/mail/static/src/models/activity/activity.js
index f500579f04e..d370b686973 100644
--- a/addons/mail/static/src/models/activity/activity.js
+++ b/addons/mail/static/src/models/activity/activity.js
@@ -209,6 +209,13 @@ function factory(dependencies) {
         // Private
         //----------------------------------------------------------------------
 
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
         /**
          * @private
          * @returns {boolean}
diff --git a/addons/mail/static/src/models/activity_type/activity_type.js b/addons/mail/static/src/models/activity_type/activity_type.js
index 7af2ae74095..f8a621a8569 100644
--- a/addons/mail/static/src/models/activity_type/activity_type.js
+++ b/addons/mail/static/src/models/activity_type/activity_type.js
@@ -6,7 +6,20 @@ const { attr, one2many } = require('mail/static/src/model/model_field.js');
 
 function factory(dependencies) {
 
-    class ActivityType extends dependencies['mail.model'] {}
+    class ActivityType extends dependencies['mail.model'] {
+
+        //----------------------------------------------------------------------
+        // Private
+        //----------------------------------------------------------------------
+
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
+    }
 
     ActivityType.fields = {
         activities: one2many('mail.activity', {
diff --git a/addons/mail/static/src/models/attachment/attachment.js b/addons/mail/static/src/models/attachment/attachment.js
index 3bfbbef0cb9..d4dcfb20fac 100644
--- a/addons/mail/static/src/models/attachment/attachment.js
+++ b/addons/mail/static/src/models/attachment/attachment.js
@@ -49,6 +49,20 @@ function factory(dependencies) {
             return data2;
         }
 
+        /**
+         * @override
+         */
+        static create(data) {
+            const isMulti = typeof data[Symbol.iterator] === 'function';
+            const dataList = isMulti ? data : [data];
+            for (const data of dataList) {
+                if (!data.id) {
+                    data.id = getAttachmentNextTemporaryId();
+                }
+            }
+            return super.create(...arguments);
+        }
+
         /**
          * View provided attachment(s), with given attachment initially. Prompts
          * the attachment viewer.
@@ -94,6 +108,13 @@ function factory(dependencies) {
         // Private
         //----------------------------------------------------------------------
 
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
         /**
          * @private
          * @returns {mail.composer[]}
@@ -185,17 +206,6 @@ function factory(dependencies) {
             return match[1];
         }
 
-        /**
-         * @private
-         * @returns {integer}
-         */
-        _computeId() {
-            if (this.isTemporary && (this.id === undefined || this.id > 0)) {
-                return getAttachmentNextTemporaryId();
-            }
-            return this.id;
-        }
-
         /**
          * @private
          * @returns {boolean}
@@ -236,18 +246,6 @@ function factory(dependencies) {
             return this.mimetype && this.mimetype.split('/').shift();
         }
 
-        /**
-         * @override
-         */
-        _createRecordLocalId(data) {
-            const { id, isTemporary = false } = data;
-            const Attachment = this.env.models['mail.attachment'];
-            if (isTemporary) {
-                return `${Attachment.modelName}_${nextTemporaryId}`;
-            }
-            return `${Attachment.modelName}_${id}`;
-        }
-
     }
 
     Attachment.fields = {
@@ -291,10 +289,7 @@ function factory(dependencies) {
                 'url',
             ],
         }),
-        id: attr({
-            compute: '_computeId',
-            dependencies: ['isTemporary'],
-        }),
+        id: attr(),
         isLinkedToComposer: attr({
             compute: '_computeIsLinkedToComposer',
             dependencies: ['composers'],
diff --git a/addons/mail/static/src/models/country/country.js b/addons/mail/static/src/models/country/country.js
index 8fe6b282a31..2e44f54712d 100644
--- a/addons/mail/static/src/models/country/country.js
+++ b/addons/mail/static/src/models/country/country.js
@@ -6,7 +6,20 @@ const { attr } = require('mail/static/src/model/model_field.js');
 
 function factory(dependencies) {
 
-    class Country extends dependencies['mail.model'] {}
+    class Country extends dependencies['mail.model'] {
+
+        //----------------------------------------------------------------------
+        // Private
+        //----------------------------------------------------------------------
+
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
+    }
 
     Country.fields = {
         id: attr(),
diff --git a/addons/mail/static/src/models/follower/follower.js b/addons/mail/static/src/models/follower/follower.js
index 78667ed755c..42e7216392e 100644
--- a/addons/mail/static/src/models/follower/follower.js
+++ b/addons/mail/static/src/models/follower/follower.js
@@ -153,6 +153,13 @@ function factory(dependencies) {
         // Private
         //----------------------------------------------------------------------
 
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
         /**
          * @private
          * @returns {string}
diff --git a/addons/mail/static/src/models/follower_subtype/follower_subtype.js b/addons/mail/static/src/models/follower_subtype/follower_subtype.js
index 37e65129c61..68c16fce189 100644
--- a/addons/mail/static/src/models/follower_subtype/follower_subtype.js
+++ b/addons/mail/static/src/models/follower_subtype/follower_subtype.js
@@ -43,6 +43,17 @@ function factory(dependencies) {
             return data2;
         }
 
+        //----------------------------------------------------------------------
+        // Private
+        //----------------------------------------------------------------------
+
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
     }
 
     FollowerSubtype.fields = {
diff --git a/addons/mail/static/src/models/mail_template/mail_template.js b/addons/mail/static/src/models/mail_template/mail_template.js
index 69d2b4c18b1..75b7b8fe4cd 100644
--- a/addons/mail/static/src/models/mail_template/mail_template.js
+++ b/addons/mail/static/src/models/mail_template/mail_template.js
@@ -56,6 +56,17 @@ function factory(dependencies) {
             }
         }
 
+        //----------------------------------------------------------------------
+        // Private
+        //----------------------------------------------------------------------
+
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
     }
 
     MailTemplate.fields = {
diff --git a/addons/mail/static/src/models/message/message.js b/addons/mail/static/src/models/message/message.js
index 889ddef8306..d38b50a3083 100644
--- a/addons/mail/static/src/models/message/message.js
+++ b/addons/mail/static/src/models/message/message.js
@@ -315,6 +315,13 @@ function factory(dependencies) {
         // Private
         //----------------------------------------------------------------------
 
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
         /**
          * @returns {boolean}
          */
@@ -432,14 +439,6 @@ function factory(dependencies) {
             return [['replace', threads]];
         }
 
-        /**
-         * @override
-         */
-        _createRecordLocalId(data) {
-            const Message = this.env.models['mail.message'];
-            return `${Message.modelName}_${data.id}`;
-        }
-
     }
 
     Message.fields = {
diff --git a/addons/mail/static/src/models/message_seen_indicator/message_seen_indicator.js b/addons/mail/static/src/models/message_seen_indicator/message_seen_indicator.js
index 9ad56eb8da0..19b4706ba1f 100644
--- a/addons/mail/static/src/models/message_seen_indicator/message_seen_indicator.js
+++ b/addons/mail/static/src/models/message_seen_indicator/message_seen_indicator.js
@@ -67,6 +67,13 @@ function factory(dependencies) {
         // Private
         //----------------------------------------------------------------------
 
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
         /**
          * Manually called as not always called when necessary
          *
diff --git a/addons/mail/static/src/models/model/model.js b/addons/mail/static/src/models/model/model.js
index 6ee5125426d..6511cafa658 100644
--- a/addons/mail/static/src/models/model/model.js
+++ b/addons/mail/static/src/models/model/model.js
@@ -39,9 +39,9 @@ function factory() {
          */
         init() {}
 
-        //--------------------------------------------------------------------------
+        //----------------------------------------------------------------------
         // Public
-        //--------------------------------------------------------------------------
+        //----------------------------------------------------------------------
 
         /**
          * Returns all records of this model that match provided criteria.
@@ -154,20 +154,9 @@ function factory() {
             this.env.modelManager.update(this, data);
         }
 
-        //--------------------------------------------------------------------------
+        //----------------------------------------------------------------------
         // Private
-        //--------------------------------------------------------------------------
-
-        /**
-         * @static
-         * @private
-         * @param {Object} data
-         * @param {any} data.id
-         * @return {function}
-         */
-        static _findFunctionFromData(data) {
-            return record => record.id === data.id;
-        }
+        //----------------------------------------------------------------------
 
         /**
          * This method generates a local id for this record that is
@@ -180,12 +169,13 @@ function factory() {
          * track relations and records in the system instead of arbitrary
          * number to differenciate them.
          *
+         * @static
          * @private
          * @param {Object} data
          * @returns {string}
          */
-        _createRecordLocalId(data) {
-            return _.uniqueId(`${this.constructor.modelName}_`);
+        static _createRecordLocalId(data) {
+            return _.uniqueId(`${this.modelName}_`);
         }
 
         /**
diff --git a/addons/mail/static/src/models/notification/notification.js b/addons/mail/static/src/models/notification/notification.js
index 95e8a013876..c8e9078b046 100644
--- a/addons/mail/static/src/models/notification/notification.js
+++ b/addons/mail/static/src/models/notification/notification.js
@@ -46,6 +46,17 @@ function factory(dependencies) {
             return data2;
         }
 
+        //----------------------------------------------------------------------
+        // Private
+        //----------------------------------------------------------------------
+
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
     }
 
     Notification.fields = {
diff --git a/addons/mail/static/src/models/notification_group/notification_group.js b/addons/mail/static/src/models/notification_group/notification_group.js
index 9fdbefc4979..415350332cc 100644
--- a/addons/mail/static/src/models/notification_group/notification_group.js
+++ b/addons/mail/static/src/models/notification_group/notification_group.js
@@ -63,9 +63,8 @@ function factory(dependencies) {
         /**
          * @override
          */
-        _createRecordLocalId(data) {
-            const NotificationGroup = this.env.models['mail.notification_group'];
-            return `${NotificationGroup.modelName}_${data.id}`;
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
         }
 
         /**
diff --git a/addons/mail/static/src/models/partner/partner.js b/addons/mail/static/src/models/partner/partner.js
index 32b02e6e60c..c78eef51289 100644
--- a/addons/mail/static/src/models/partner/partner.js
+++ b/addons/mail/static/src/models/partner/partner.js
@@ -156,6 +156,13 @@ function factory(dependencies) {
         // Private
         //----------------------------------------------------------------------
 
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
         /**
          * @static
          * @private
@@ -211,14 +218,6 @@ function factory(dependencies) {
             return this.name || this.display_name;
         }
 
-        /**
-         * @override
-         */
-        _createRecordLocalId(data) {
-            const Partner = this.env.models['mail.partner'];
-            return `${Partner.modelName}_${data.id}`;
-        }
-
     }
 
     Partner.fields = {
diff --git a/addons/mail/static/src/models/thread/thread.js b/addons/mail/static/src/models/thread/thread.js
index ceb4a366ec3..4459912d6f6 100644
--- a/addons/mail/static/src/models/thread/thread.js
+++ b/addons/mail/static/src/models/thread/thread.js
@@ -764,8 +764,13 @@ function factory(dependencies) {
         /**
          * @override
          */
-        static _findFunctionFromData(data) {
-            return record => record.id === data.id && record.model === data.model;
+        static _createRecordLocalId(data) {
+            const { channel_type, id, model } = data;
+            let threadModel = model;
+            if (!threadModel && channel_type) {
+                threadModel = 'mail.channel';
+            }
+            return `${this.modelName}_${threadModel}_${id}`;
         }
 
         /**
@@ -1006,22 +1011,6 @@ function factory(dependencies) {
             );
         }
 
-        /**
-         * @override
-         */
-        _createRecordLocalId(data) {
-            const { channel_type, id, isTemporary = false, model } = data;
-            let threadModel = model;
-            if (!threadModel && channel_type) {
-                threadModel = 'mail.channel';
-            }
-            const Thread = this.env.models['mail.thread'];
-            if (isTemporary) {
-                return `${Thread.modelName}_${id}`;
-            }
-            return `${Thread.modelName}_${threadModel}_${id}`;
-        }
-
         /**
          * @private
          * @param {Object} param0
diff --git a/addons/mail/static/src/models/thread_cache/thread_cache.js b/addons/mail/static/src/models/thread_cache/thread_cache.js
index b4fe3ca28c3..9d0b4e98e57 100644
--- a/addons/mail/static/src/models/thread_cache/thread_cache.js
+++ b/addons/mail/static/src/models/thread_cache/thread_cache.js
@@ -94,6 +94,17 @@ function factory(dependencies) {
         // Private
         //----------------------------------------------------------------------
 
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            const {
+                stringifiedDomain = '[]',
+                thread: [[commandInsert, thread]],
+            } = data;
+            return `${this.modelName}_[${thread.localId}]_<${stringifiedDomain}>`;
+        }
+
         /**
          * @private
          */
@@ -204,18 +215,6 @@ function factory(dependencies) {
             )]];
         }
 
-        /**
-         * @override
-         */
-        _createRecordLocalId(data) {
-            const {
-                stringifiedDomain = '[]',
-                thread: [[commandInsert, thread]],
-            } = data;
-            const ThreadCache = this.env.models['mail.thread_cache'];
-            return `${ThreadCache.modelName}_[${thread.localId}]_<${stringifiedDomain}>`;
-        }
-
         /**
          * @private
          * @param {Array} domain
diff --git a/addons/mail/static/src/models/thread_partner_seen_info/thread_partner_seen_info.js b/addons/mail/static/src/models/thread_partner_seen_info/thread_partner_seen_info.js
index 6ea0148d6d0..1a2d19480a3 100644
--- a/addons/mail/static/src/models/thread_partner_seen_info/thread_partner_seen_info.js
+++ b/addons/mail/static/src/models/thread_partner_seen_info/thread_partner_seen_info.js
@@ -6,7 +6,20 @@ const { attr, many2one } = require('mail/static/src/model/model_field.js');
 
 function factory(dependencies) {
 
-    class ThreadPartnerSeenInfo extends dependencies['mail.model'] {}
+    class ThreadPartnerSeenInfo extends dependencies['mail.model'] {
+
+        //----------------------------------------------------------------------
+        // Private
+        //----------------------------------------------------------------------
+
+        /**
+         * @override
+         */
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
+        }
+
+    }
 
     ThreadPartnerSeenInfo.modelName = 'mail.thread_partner_seen_info';
 
diff --git a/addons/mail/static/src/models/user/user.js b/addons/mail/static/src/models/user/user.js
index 2e6206c79f5..20495e25aa1 100644
--- a/addons/mail/static/src/models/user/user.js
+++ b/addons/mail/static/src/models/user/user.js
@@ -42,8 +42,8 @@ function factory(dependencies) {
         /**
          * @override
          */
-        _createRecordLocalId(data) {
-            return `${this.env.models['mail.user'].modelName}_${data.id}`;
+        static _createRecordLocalId(data) {
+            return `${this.modelName}_${data.id}`;
         }
 
         /**