diff --git a/backend/LexBoxApi/GraphQL/ProjectMutations.cs b/backend/LexBoxApi/GraphQL/ProjectMutations.cs
index ab03ad753e..06104a22c9 100644
--- a/backend/LexBoxApi/GraphQL/ProjectMutations.cs
+++ b/backend/LexBoxApi/GraphQL/ProjectMutations.cs
@@ -163,7 +163,7 @@ public async Task<BulkAddProjectMembersResult> BulkAddProjectMembers(
                     Username = username,
                     Name = name,
                     Email = email,
-                    LocalizationCode = "en", // TODO: input.Locale,
+                    LocalizationCode = input.Locale,
                     Salt = salt,
                     PasswordHash = PasswordHashing.HashPassword(input.PasswordHash, salt, true),
                     PasswordStrength = 0, // Shared password, so always considered strength 0, we don't call Zxcvbn here
diff --git a/backend/LexBoxApi/Models/Project/ProjectMemberInputs.cs b/backend/LexBoxApi/Models/Project/ProjectMemberInputs.cs
index 05c3397875..87ac2443fd 100644
--- a/backend/LexBoxApi/Models/Project/ProjectMemberInputs.cs
+++ b/backend/LexBoxApi/Models/Project/ProjectMemberInputs.cs
@@ -4,6 +4,6 @@ namespace LexBoxApi.Models.Project;
 
 public record AddProjectMemberInput(Guid ProjectId, string? UsernameOrEmail, Guid? UserId, ProjectRole Role, bool canInvite);
 
-public record BulkAddProjectMembersInput(Guid ProjectId, string[] Usernames, ProjectRole Role, string PasswordHash);
+public record BulkAddProjectMembersInput(Guid ProjectId, string[] Usernames, ProjectRole Role, string PasswordHash, string Locale = User.DefaultLocalizationCode);
 
 public record ChangeProjectMemberRoleInput(Guid ProjectId, Guid UserId, ProjectRole Role);
diff --git a/frontend/schema.graphql b/frontend/schema.graphql
index f562dc877b..932fef84a5 100644
--- a/frontend/schema.graphql
+++ b/frontend/schema.graphql
@@ -751,6 +751,7 @@ input BulkAddProjectMembersInput {
   usernames: [String!]!
   role: ProjectRole!
   passwordHash: String!
+  locale: String! = "en"
 }
 
 input ChangeOrgMemberRoleInput {
diff --git a/frontend/src/routes/(authenticated)/project/[project_code]/+page.svelte b/frontend/src/routes/(authenticated)/project/[project_code]/+page.svelte
index 2f266659b7..aef087ce6e 100644
--- a/frontend/src/routes/(authenticated)/project/[project_code]/+page.svelte
+++ b/frontend/src/routes/(authenticated)/project/[project_code]/+page.svelte
@@ -602,7 +602,7 @@
           </BadgeButton>
 
           <AddProjectMember bind:this={addProjectMember} {project} />
-          <BulkAddProjectMembers projectId={project.id} />
+          <BulkAddProjectMembers projectId={project.id} userLocale={user.locale} />
         {/snippet}
         <UserModal bind:this={userModal} />
 
diff --git a/frontend/src/routes/(authenticated)/project/[project_code]/+page.ts b/frontend/src/routes/(authenticated)/project/[project_code]/+page.ts
index a111f48c36..a1a6f94b95 100644
--- a/frontend/src/routes/(authenticated)/project/[project_code]/+page.ts
+++ b/frontend/src/routes/(authenticated)/project/[project_code]/+page.ts
@@ -241,8 +241,6 @@ export async function _addProjectMember(input: AddProjectMemberInput): $OpResult
   return result;
 }
 
-// public record BulkAddProjectMembersInput(Guid ProjectId, string[] Usernames, ProjectRole Role, string PasswordHash);
-
 export async function _bulkAddProjectMembers(input: BulkAddProjectMembersInput): $OpResult<BulkAddProjectMembersMutation> {
   //language=GraphQL
   const result = await getClient()
diff --git a/frontend/src/routes/(authenticated)/project/[project_code]/BulkAddProjectMembers.svelte b/frontend/src/routes/(authenticated)/project/[project_code]/BulkAddProjectMembers.svelte
index 31cf09cbde..0c9a908d38 100644
--- a/frontend/src/routes/(authenticated)/project/[project_code]/BulkAddProjectMembers.svelte
+++ b/frontend/src/routes/(authenticated)/project/[project_code]/BulkAddProjectMembers.svelte
@@ -1,7 +1,7 @@
 <script lang="ts">
   import {BadgeButton, MemberBadge} from '$lib/components/Badges';
   import {DialogResponse, FormModal, type FormSubmitReturn} from '$lib/components/modals';
-  import {Input, TextArea, isEmail, passwordFormRules} from '$lib/forms';
+  import {DisplayLanguageSelect, Input, TextArea, isEmail, passwordFormRules} from '$lib/forms';
   import {ProjectRole, type BulkAddProjectMembersResult} from '$lib/gql/types';
   import t from '$lib/i18n';
   import {z} from 'zod';
@@ -25,12 +25,14 @@
 
   interface Props {
     projectId: string;
+    userLocale: string;
   }
 
-  const { projectId }: Props = $props();
+  const { projectId, userLocale }: Props = $props();
   const schema = z.object({
     usernamesText: z.string().trim().min(1, $t('project_page.bulk_add_members.empty_user_field')),
     password: passwordFormRules($t),
+    locale: z.string().trim().min(2).default(userLocale),
   });
 
   let formModal: FormModal<typeof schema> | undefined = $state();
@@ -76,6 +78,7 @@
         usernames,
         //todo allow setting users as Observer
         role: ProjectRole.Editor, // Managers not allowed to have shared passwords
+        locale: state.locale.currentValue,
       });
 
       const invalidEmailError = error?.byType('InvalidEmailError');
@@ -121,6 +124,7 @@
           error={errors.password}
         />
         <PasswordStrengthMeter password={$form!.password} scoreOverride={0} />
+        <DisplayLanguageSelect bind:value={$form!.locale} />
         <div class="contents usernames">
           <TextArea
             id="usernamesText"