diff --git a/src/main/scala/app/IndexController.scala b/src/main/scala/app/IndexController.scala
index 0443729..9a2bc37 100644
--- a/src/main/scala/app/IndexController.scala
+++ b/src/main/scala/app/IndexController.scala
@@ -88,8 +88,6 @@
 
   /**
    * JSON API for collaborator completion.
-   *
-   * TODO Move to other controller?
    */
   get("/_user/proposals")(usersOnly {
     contentType = formats("json")
@@ -98,5 +96,11 @@
     )
   })
 
+  /**
+   * JSON APU for checking user existence.
+   */
+  post("/_user/existence")(usersOnly {
+    getAccountByUserName(params("userName")).isDefined
+  })
 
 }
diff --git a/src/main/scala/app/UserManagementController.scala b/src/main/scala/app/UserManagementController.scala
index ee568f3..6125039 100644
--- a/src/main/scala/app/UserManagementController.scala
+++ b/src/main/scala/app/UserManagementController.scala
@@ -182,11 +182,6 @@
     }
   })
 
-  // TODO Move to other generic controller?
-  post("/admin/users/_usercheck"){
-    getAccountByUserName(params("userName")).isDefined
-  }
-
   private def members: Constraint = new Constraint(){
     override def validate(name: String, value: String, messages: Messages): Option[String] = {
       if(value.split(",").exists {
diff --git a/src/main/twirl/account/group.scala.html b/src/main/twirl/account/group.scala.html
index f97b135..d6d7cf6 100644
--- a/src/main/twirl/account/group.scala.html
+++ b/src/main/twirl/account/group.scala.html
@@ -60,7 +60,7 @@
   });
 
   $('#addMember').click(function(){
-    $('#error-memberName').text('');
+    $('#error-members').text('');
     var userName = $('#memberName').val();
 
     // check empty
@@ -73,18 +73,18 @@
       return $(this).data('name') == userName;
     }).length > 0;
     if(exists){
-      $('#error-memberName').text('User has been already added.');
+      $('#error-members').text('User has been already added.');
       return false;
     }
 
     // check existence
-    $.post('@path/admin/users/_usercheck', {
+    $.post('@path/_user/existence', {
       'userName': userName
     }, function(data, status){
       if(data == 'true'){
         addMemberHTML(userName, false);
       } else {
-        $('#error-memberName').text('User does not exist.');
+        $('#error-members').text('User does not exist.');
       }
     });
   });
diff --git a/src/main/twirl/admin/users/group.scala.html b/src/main/twirl/admin/users/group.scala.html
index 37369aa..8b7672d 100644
--- a/src/main/twirl/admin/users/group.scala.html
+++ b/src/main/twirl/admin/users/group.scala.html
@@ -59,7 +59,7 @@
   });
 
   $('#addMember').click(function(){
-    $('#error-memberName').text('');
+    $('#error-members').text('');
     var userName = $('#memberName').val();
 
     // check empty
@@ -72,18 +72,18 @@
       return $(this).data('name') == userName;
     }).length > 0;
     if(exists){
-      $('#error-memberName').text('User has been already added.');
+      $('#error-members').text('User has been already added.');
       return false;
     }
 
     // check existence
-    $.post('@path/admin/users/_usercheck', {
+    $.post('@path/_user/existence', {
       'userName': userName
     }, function(data, status){
       if(data == 'true'){
         addMemberHTML(userName, false);
       } else {
-        $('#error-memberName').text('User does not exist.');
+        $('#error-members').text('User does not exist.');
       }
     });
   });