diff --git a/src/components/specific/users/invitation-form/ProjectInvitationForm.vue b/src/components/specific/users/invitation-form/ProjectInvitationForm.vue
index 7b743399c..ec795ff85 100644
--- a/src/components/specific/users/invitation-form/ProjectInvitationForm.vue
+++ b/src/components/specific/users/invitation-form/ProjectInvitationForm.vue
@@ -29,8 +29,9 @@ const errorMessage = ref("");
 const submit = async ({ emails, role }) => {
   const existingEmails = props.users.map(user => user.email);
 
-  if (emails.some(eml => existingEmails.includes(eml))) {
-    errorMessage.value = t("InvitationForm.userAlreadyExistInputErrorMessage");
+  const alreadyExistingEmail = emails.find(eml => existingEmails.includes(eml));
+  if (alreadyExistingEmail) {
+    errorMessage.value = t("InvitationForm.projectUserAlreadyExistError", { email: alreadyExistingEmail });
     return;
   }
 
diff --git a/src/components/specific/users/invitation-form/SpaceInvitationForm.vue b/src/components/specific/users/invitation-form/SpaceInvitationForm.vue
index f28f8f958..716213a34 100644
--- a/src/components/specific/users/invitation-form/SpaceInvitationForm.vue
+++ b/src/components/specific/users/invitation-form/SpaceInvitationForm.vue
@@ -1,6 +1,8 @@
 <script setup>
 import { eachLimit } from "async";
+import { ref } from "vue";
 import { useI18n } from "vue-i18n";
+import { SPACE_ROLE } from "../../../../config/spaces.js";
 import { useSpaces } from "../../../../state/spaces.js";
 import { useAppNotification } from "../../app/app-notification/app-notification.js";
 
@@ -27,29 +29,46 @@ const props = defineProps({
 
 const emit = defineEmits(["close", "success"]);
 
+const errorMessage = ref("");
+
 const submit = async ({ emails }) => {
   let isExistingUsersOnly = true;
 
   await eachLimit(emails, 10, async eml => {
     const user = props.users.find(user => user.email === eml);
-    if (user) {
-      await updateSpaceUser(props.space, { ...user, cloud_role: 100 });
-      return;
-    }
 
-    isExistingUsersOnly = false;
     if (props.admin) {
-      await sendSpaceInvitation(props.space, { email: eml });
+      if (user) {
+        if (user.cloud_role === SPACE_ROLE.ADMIN) {
+          errorMessage.value = t("InvitationForm.spaceAdminAlreadyExistError", { email: eml });
+        } else {
+          await updateSpaceUser(props.space, { ...user, cloud_role: 100 });
+        }
+      } else {
+        isExistingUsersOnly = false;
+        await sendSpaceInvitation(props.space, { email: eml });
+      }
     } else {
-      await sendSpaceInvitation(props.space, {
-        email: eml,
-        in_all_projects: true,
-        project_role: 50,
-        role: 50,
-      });
+      if (user) {
+        if (user.cloud_role === SPACE_ROLE.ADMIN) {
+          errorMessage.value = t("InvitationForm.spaceAdminAlreadyExistError", { email: eml });
+        } else {
+          errorMessage.value = t("InvitationForm.spaceUserAlreadyExistError", { email: eml });
+        }
+      } else {
+        isExistingUsersOnly = false;
+        await sendSpaceInvitation(props.space, {
+          email: eml,
+          role: 50,
+          in_all_projects: true,
+          project_role: 50,
+        });
+      }
     }
   });
 
+  if (errorMessage.value) return;
+
   pushNotification(
     {
       type: "success",
@@ -66,5 +85,9 @@ const submit = async ({ emails }) => {
 </script>
 
 <template>
-  <InvitationForm @cancel="$emit('close')" @submit="submit" />
+  <InvitationForm
+    :error="errorMessage"
+    @cancel="$emit('close')"
+    @submit="submit"
+  />
 </template>
diff --git a/src/components/specific/users/user-role-badge/UserRoleBadge.vue b/src/components/specific/users/user-role-badge/UserRoleBadge.vue
index a94a7af59..1fcd488bb 100644
--- a/src/components/specific/users/user-role-badge/UserRoleBadge.vue
+++ b/src/components/specific/users/user-role-badge/UserRoleBadge.vue
@@ -45,6 +45,7 @@ export default {
       if (props.projectRole === PROJECT_ROLE.GUEST) {
         return "guest";
       }
+
       return "projectUser";
     });
 
diff --git a/src/i18n/lang/de.json b/src/i18n/lang/de.json
index 56003cad9..d12b95fb7 100644
--- a/src/i18n/lang/de.json
+++ b/src/i18n/lang/de.json
@@ -218,7 +218,7 @@
     "submitButtonText": "Einladen",
     "successNotifText": "Einladung versendet",
     "successUserToAdmin": "Der Nutzer wurde zum Administrator befördert.",
-    "userAlreadyExistInputErrorMessage": "Der Nutzer ist bereits in Ihren Projekt."
+    "projectUserAlreadyExistError": "Der Nutzer ist bereits in Ihren Projekt."
   },
   "ModelActionsCell": {
     "addTagsButtonText": "Tags hinzufügen",
diff --git a/src/i18n/lang/en.json b/src/i18n/lang/en.json
index c55842a97..34c903bab 100644
--- a/src/i18n/lang/en.json
+++ b/src/i18n/lang/en.json
@@ -82,12 +82,10 @@
         "folder_permissions_updated": "Folder permissions updated",
         "folder_renamed": "Folder renamed",
         "folder_moved": "Folder moved",
-
         "cloud_invitation_sent": "Invitation sent",
         "cloud_invitation_canceled": "Invitation canceled",
         "cloud_invitation_accepted": "Invitation accepted",
         "cloud_invitation_denied": "Invitation denied",
-
         "project_invitation_sent": "Project invitation sent",
         "project_invitation_canceled": "Project invitation canceled",
         "project_invitation_accepted": "Project invitation accepted",
@@ -288,7 +286,9 @@
     "submitButtonText": "Send invitation",
     "successNotifText": "Invitation sent",
     "successUserToAdmin": "The user has now admin role",
-    "userAlreadyExistInputErrorMessage": "User is already in the project"
+    "projectUserAlreadyExistError": "User {email} is already in the project",
+    "spaceUserAlreadyExistError": "User {email} is already in the space",
+    "spaceAdminAlreadyExistError": "User {email} is already an admin of the space"
   },
   "ModelActionsCell": {
     "addTagsButtonText": "Add tags",
@@ -1046,4 +1046,4 @@
     "title": "Delete {visasCount} visas",
     "message": "You are about to delete the visas on the following files:"
   }
-}
+}
\ No newline at end of file
diff --git a/src/i18n/lang/es.json b/src/i18n/lang/es.json
index 36412d363..a17dc7201 100644
--- a/src/i18n/lang/es.json
+++ b/src/i18n/lang/es.json
@@ -218,7 +218,7 @@
     "submitButtonText": "Invitar",
     "successNotifText": "Invitación enviada",
     "successUserToAdmin": "El usuario ha sido ascendido a administrador",
-    "userAlreadyExistInputErrorMessage": "El usuario ya está en su proyecto"
+    "projectUserAlreadyExistError": "El usuario ya está en su proyecto"
   },
   "ModelActionsCell": {
     "addTagsButtonText": "Añadir etiquetas",
diff --git a/src/i18n/lang/fr.json b/src/i18n/lang/fr.json
index f7205986d..b4ee5221d 100644
--- a/src/i18n/lang/fr.json
+++ b/src/i18n/lang/fr.json
@@ -153,12 +153,10 @@
         "folder_permissions_updated": "Modification des droits d’accès",
         "folder_renamed": "Renommage du dossier",
         "folder_moved": "Déplacement du dossier",
-
         "cloud_invitation_sent": "Invitation envoyée",
         "cloud_invitation_canceled": "Invitation annulée",
         "cloud_invitation_accepted": "Invitation acceptée",
         "cloud_invitation_denied": "Invitation refusée",
-
         "project_invitation_sent": "Invitation projet envoyée",
         "project_invitation_canceled": "Invitation projet annulée",
         "project_invitation_accepted": "Invitation projet acceptée",
@@ -388,7 +386,9 @@
   "InvitationForm": {
     "emailInputPlaceholder": "Email de l'utilisateur",
     "emailInputErrorMessage": "Email invalide",
-    "userAlreadyExistInputErrorMessage": "L'utilisateur est déjà dans votre projet",
+    "projectUserAlreadyExistError": "L'utilisateur {email} est déjà dans votre projet",
+    "spaceUserAlreadyExistError": "L'utilisateur {email} est déjà dans votre espace",
+    "spaceAdminAlreadyExistError": "L'utilisateur {email} est déjà admin dans votre espace",
     "roleInputLabel": "Rôle",
     "roles": {
       "admin": "Administrateur",
@@ -1071,4 +1071,4 @@
     "title": "Suppression de {visasCount} visas",
     "message": "Vous êtes sur le point de supprimer les visas sur les fichiers suivants :"
   }
-}
+}
\ No newline at end of file