diff --git a/addons/hr/static/src/models/employee/employee.js b/addons/hr/static/src/models/employee/employee.js
index 6d3c12cb14b..ef749203364 100644
--- a/addons/hr/static/src/models/employee/employee.js
+++ b/addons/hr/static/src/models/employee/employee.js
@@ -178,7 +178,9 @@ function factory(dependencies) {
         /**
          * Unique identifier for this employee.
          */
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         /**
          * Partner related to this employee.
          */
diff --git a/addons/mail/static/src/model/model_field.js b/addons/mail/static/src/model/model_field.js
index 55617d5eaa1..940e9efd6cd 100644
--- a/addons/mail/static/src/model/model_field.js
+++ b/addons/mail/static/src/model/model_field.js
@@ -27,6 +27,7 @@ class ModelField {
         isCausal = false,
         related,
         relationType,
+        required = false,
         to,
     } = {}) {
         const id = _.uniqueId('field_');
@@ -151,6 +152,13 @@ class ModelField {
          * and 'many2many'.
          */
         this.relationType = relationType;
+        /**
+         * Determine whether the field is required or not.
+         *
+         * Empty value is systematically undefined.
+         * null or empty string are NOT considered empty value, meaning these values meet the requirement.
+        */
+        this.required = required;
         /**
          * This prop only makes sense in a relational field. Determine which
          * model name this relation refers to.
diff --git a/addons/mail/static/src/model/model_manager.js b/addons/mail/static/src/model/model_manager.js
index 73c3c313ed4..fe53840d85c 100644
--- a/addons/mail/static/src/model/model_manager.js
+++ b/addons/mail/static/src/model/model_manager.js
@@ -307,6 +307,7 @@ class ModelManager {
                             'dependencies',
                             'fieldType',
                             'related',
+                            'required',
                         ].includes(key)
                     );
                     if (invalidKeys.length > 0) {
@@ -324,6 +325,7 @@ class ModelManager {
                             'isCausal',
                             'related',
                             'relationType',
+                            'required',
                             'to',
                         ].includes(key)
                     );
@@ -336,6 +338,9 @@ class ModelManager {
                     if (field.isCausal && !(['one2many', 'one2one'].includes(field.relationType))) {
                         throw new Error(`Relational field "${Model.modelName}/${fieldName}" has "isCausal" true with a relation of type "${field.relationType}" but "isCausal" is only supported for "one2many" and "one2one".`);
                     }
+                    if (field.required && !(['one2one', 'many2one'].includes(field.relationType))) {
+                        throw new Error(`Relational field "${Model.modelName}/${fieldName}" has "required" true with a relation of type "${field.relationType}" but "required" is only supported for "one2one" and "many2one".`);
+                    }
                 }
                 // 3. Computed field.
                 if (field.compute && !(typeof field.compute === 'string')) {
@@ -708,6 +713,16 @@ class ModelManager {
         for (const record of this._updatedRecords) {
             record.__state++;
         }
+
+        // handle required field.
+        for (const record of this._updatedRecords) {
+            for (const required of record.constructor.__requiredFieldsList) {
+                if (record[required.fieldName] === undefined) {
+                    throw Error(`Field ${required.fieldName} of ${record.localId} is required.`);
+                }
+            }
+        }
+
         this._updatedRecords.clear();
 
         // Trigger at most one useStore call per update cycle
@@ -977,6 +992,9 @@ class ModelManager {
             Model.__fieldMap = Model.__combinedFields;
             // List of all fields, for iterating.
             Model.__fieldList = Object.values(Model.__fieldMap);
+            Model.__requiredFieldsList = Model.__fieldList.filter(
+                field => field.required
+            );
             // Add field accessors.
             for (const field of Model.__fieldList) {
                 Object.defineProperty(Model.prototype, field.fieldName, {
diff --git a/addons/mail/static/src/models/activity/activity.js b/addons/mail/static/src/models/activity/activity.js
index b2d8ef3cb13..3508636db16 100644
--- a/addons/mail/static/src/models/activity/activity.js
+++ b/addons/mail/static/src/models/activity/activity.js
@@ -283,7 +283,9 @@ function factory(dependencies) {
             default: false,
         }),
         icon: attr(),
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         isCurrentPartnerAssignee: attr({
             compute: '_computeIsCurrentPartnerAssignee',
             default: false,
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 f8a621a8569..6c12c691221 100644
--- a/addons/mail/static/src/models/activity_type/activity_type.js
+++ b/addons/mail/static/src/models/activity_type/activity_type.js
@@ -26,7 +26,9 @@ function factory(dependencies) {
             inverse: 'type',
         }),
         displayName: attr(),
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
     };
 
     ActivityType.modelName = 'mail.activity_type';
diff --git a/addons/mail/static/src/models/attachment/attachment.js b/addons/mail/static/src/models/attachment/attachment.js
index 7399dee7b33..03edf5abcab 100644
--- a/addons/mail/static/src/models/attachment/attachment.js
+++ b/addons/mail/static/src/models/attachment/attachment.js
@@ -321,7 +321,9 @@ function factory(dependencies) {
                 'url',
             ],
         }),
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         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 fb3617cf783..8dd48aac442 100644
--- a/addons/mail/static/src/models/country/country.js
+++ b/addons/mail/static/src/models/country/country.js
@@ -41,7 +41,9 @@ function factory(dependencies) {
                 'code',
             ],
         }),
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         name: attr(),
     };
 
diff --git a/addons/mail/static/src/models/follower/follower.js b/addons/mail/static/src/models/follower/follower.js
index 183c20e4684..591e6a2ee57 100644
--- a/addons/mail/static/src/models/follower/follower.js
+++ b/addons/mail/static/src/models/follower/follower.js
@@ -239,7 +239,9 @@ function factory(dependencies) {
         followedThread: many2one('mail.thread', {
             inverse: 'followers',
         }),
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         isActive: attr({
             default: true,
         }),
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 68c16fce189..2b2a571d7e4 100644
--- a/addons/mail/static/src/models/follower_subtype/follower_subtype.js
+++ b/addons/mail/static/src/models/follower_subtype/follower_subtype.js
@@ -57,7 +57,9 @@ function factory(dependencies) {
     }
 
     FollowerSubtype.fields = {
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         isDefault: attr({
             default: false,
         }),
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 3144c3147c3..ba75bbdcc0b 100644
--- a/addons/mail/static/src/models/mail_template/mail_template.js
+++ b/addons/mail/static/src/models/mail_template/mail_template.js
@@ -69,7 +69,9 @@ function factory(dependencies) {
         activities: many2many('mail.activity', {
             inverse: 'mailTemplates',
         }),
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         name: attr(),
     };
 
diff --git a/addons/mail/static/src/models/message/message.js b/addons/mail/static/src/models/message/message.js
index c3318aa8906..fe598f168e9 100644
--- a/addons/mail/static/src/models/message/message.js
+++ b/addons/mail/static/src/models/message/message.js
@@ -553,7 +553,9 @@ function factory(dependencies) {
             default: false,
             dependencies: ['isModeratedByCurrentPartner'],
         }),
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         isCurrentPartnerAuthor: attr({
             compute: '_computeIsCurrentPartnerAuthor',
             default: false,
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 dd1848aaf7b..e44bd05b8b5 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
@@ -262,7 +262,9 @@ function factory(dependencies) {
          * (required fields) should improve and let us just use the relational
          * fields.
          */
-        channelId: attr(),
+        channelId: attr({
+            required: true,
+        }),
         hasEveryoneFetched: attr({
             compute: '_computeHasEveryoneFetched',
             default: false,
@@ -321,7 +323,9 @@ function factory(dependencies) {
          * (required fields) should improve and let us just use the relational
          * fields.
          */
-        messageId: attr(),
+        messageId: attr({
+            required: true,
+        }),
         partnersThatHaveFetched: many2many('mail.partner', {
             compute: '_computePartnersThatHaveFetched',
             dependencies: ['messageAuthor', 'messageId', 'threadPartnerSeenInfos'],
diff --git a/addons/mail/static/src/models/notification/notification.js b/addons/mail/static/src/models/notification/notification.js
index 047faee95b8..f74dd64339a 100644
--- a/addons/mail/static/src/models/notification/notification.js
+++ b/addons/mail/static/src/models/notification/notification.js
@@ -61,7 +61,9 @@ function factory(dependencies) {
 
     Notification.fields = {
         failure_type: attr(),
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         message: many2one('mail.message', {
             inverse: 'notifications',
         }),
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 89111a4ed74..4da0dccbe8f 100644
--- a/addons/mail/static/src/models/notification_group/notification_group.js
+++ b/addons/mail/static/src/models/notification_group/notification_group.js
@@ -98,7 +98,9 @@ function factory(dependencies) {
 
     NotificationGroup.fields = {
         date: attr(),
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         notification_type: attr(),
         notifications: one2many('mail.notification'),
         res_id: attr(),
diff --git a/addons/mail/static/src/models/partner/partner.js b/addons/mail/static/src/models/partner/partner.js
index e9a2135f606..80859d74244 100644
--- a/addons/mail/static/src/models/partner/partner.js
+++ b/addons/mail/static/src/models/partner/partner.js
@@ -311,7 +311,9 @@ function factory(dependencies) {
         hasCheckedUser: attr({
             default: false,
         }),
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         im_status: attr(),
         memberThreads: many2many('mail.thread', {
             inverse: 'members',
diff --git a/addons/mail/static/src/models/thread/thread.js b/addons/mail/static/src/models/thread/thread.js
index 176a8afb501..36d50a7c4cf 100644
--- a/addons/mail/static/src/models/thread/thread.js
+++ b/addons/mail/static/src/models/thread/thread.js
@@ -1653,7 +1653,9 @@ function factory(dependencies) {
                 'model',
             ],
         }),
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         /**
          * States whether this thread is a `mail.channel` qualified as chat.
          *
@@ -1834,7 +1836,9 @@ function factory(dependencies) {
         messagingCurrentPartner: many2one('mail.partner', {
             related: 'messaging.currentPartner',
         }),
-        model: attr(),
+        model: attr({
+            required: true,
+        }),
         model_name: attr(),
         moderation: attr({
             default: false,
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 8fd3b95af45..c4134d6737a 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
@@ -59,7 +59,9 @@ function factory(dependencies) {
          * (required fields) should improve and let us just use the relational
          * fields.
          */
-        channelId: attr(),
+        channelId: attr({
+            required: true,
+        }),
         lastFetchedMessage: many2one('mail.message'),
         lastSeenMessage: many2one('mail.message'),
         /**
@@ -87,7 +89,9 @@ function factory(dependencies) {
          * (required fields) should improve and let us just use the relational
          * fields.
          */
-        partnerId: attr(),
+        partnerId: attr({
+            required: true,
+        }),
         /**
          * Thread (channel) that this seen info is related to.
          *
diff --git a/addons/mail/static/src/models/user/user.js b/addons/mail/static/src/models/user/user.js
index 172b8c5b780..2bf958bdbd8 100644
--- a/addons/mail/static/src/models/user/user.js
+++ b/addons/mail/static/src/models/user/user.js
@@ -203,7 +203,9 @@ function factory(dependencies) {
     }
 
     User.fields = {
-        id: attr(),
+        id: attr({
+            required: true,
+        }),
         display_name: attr({
             compute: '_computeDisplayName',
             dependencies: [