diff --git a/webapp/packages/plugin-authentication/src/Administration/Users/UserForm/UserFormController.ts b/webapp/packages/plugin-authentication/src/Administration/Users/UserForm/UserFormController.ts
index 6df0b0ee1f..c9ccfc9983 100644
--- a/webapp/packages/plugin-authentication/src/Administration/Users/UserForm/UserFormController.ts
+++ b/webapp/packages/plugin-authentication/src/Administration/Users/UserForm/UserFormController.ts
@@ -143,11 +143,21 @@ export class UserFormController implements IInitializableController, IDestructib
   };
 
   private validate() {
-    if (!this.credentials.login) {
+    if (!this.credentials.login.trim()) {
       this.notificationService.logError({ title: 'authentication_user_login_not_set' });
       return;
     }
 
+    if (this.rolesManagerService.roles.has(this.credentials.login)) {
+      this.notificationService.logError({ title: 'authentication_user_login_cant_be_used' });
+      return;
+    }
+
+    if (this.usersResource.has(this.credentials.login)) {
+      this.notificationService.logError({ title: 'authentication_user_login_already_exists' });
+      return;
+    }
+
     if (!this.isRoleSelected()) {
       this.notificationService.logError({ title: 'authentication_user_role_not_set' });
       return;
diff --git a/webapp/packages/plugin-authentication/src/locales/en.ts b/webapp/packages/plugin-authentication/src/locales/en.ts
index 54fda62997..54598fa879 100644
--- a/webapp/packages/plugin-authentication/src/locales/en.ts
+++ b/webapp/packages/plugin-authentication/src/locales/en.ts
@@ -25,4 +25,6 @@ export default [
   ['authentication_user_role_not_set', 'At least one role must be selected'],
   ['authentication_user_password_not_set', 'Password is required'],
   ['authentication_user_passwords_not_match', "Passwords don't match"],
+  ['authentication_user_login_already_exists', 'A user with this name already exists'],
+  ['authentication_user_login_cant_be_used', 'Sorry, that name cannot be used'],
 ];
diff --git a/webapp/packages/plugin-authentication/src/locales/ru.ts b/webapp/packages/plugin-authentication/src/locales/ru.ts
index f64a4c792a..5a59ecddc9 100644
--- a/webapp/packages/plugin-authentication/src/locales/ru.ts
+++ b/webapp/packages/plugin-authentication/src/locales/ru.ts
@@ -25,4 +25,6 @@ export default [
   ['authentication_user_role_not_set', 'Должна быть выбрана минимум одна роль'],
   ['authentication_user_password_not_set', 'Пароль не задан'],
   ['authentication_user_passwords_not_match', 'Пароли не совпадают'],
+  ['authentication_user_login_already_exists', 'Пользователь с таким именем уже существует'],
+  ['authentication_user_login_cant_be_used', 'Данное имя нельзя использовать'],
 ];