diff --git a/Command/ChillImportUsersCommand.php b/Command/ChillImportUsersCommand.php
index db05cc250..38da1daf4 100644
--- a/Command/ChillImportUsersCommand.php
+++ b/Command/ChillImportUsersCommand.php
@@ -19,6 +19,7 @@ use Symfony\Component\Security\Core\Encoder\UserPasswordEncoderInterface;
 use Chill\MainBundle\Entity\GroupCenter;
 use Chill\MainBundle\Entity\PermissionsGroup;
 use Symfony\Component\Console\Question\ChoiceQuestion;
+use League\Csv\Writer;
 
 class ChillImportUsersCommand extends ContainerAwareCommand
 {
@@ -92,6 +93,12 @@ class ChillImportUsersCommand extends ContainerAwareCommand
      */
     protected $groupCenters = [];
     
+    /**
+     *
+     * @var Writer
+     */
+    protected $output = null;
+    
     public function __construct(
         EntityManagerInterface $em,
         LoggerInterface $logger,
@@ -118,7 +125,8 @@ class ChillImportUsersCommand extends ContainerAwareCommand
             ->setHelp("Import users from a csv file. Users are added to centers contained in the file. Headers are used to detect columns. Adding to multiple centers can be done by using a `grouping centers` file, which will group multiple centers into a signle alias, used in 'centers' column.")
             ->addArgument('csvfile', InputArgument::REQUIRED, 'Path to the csv file. Columns are: `username`, `email`, `center` (can contain alias), `permission group`')
             ->addOption('grouping-centers', null, InputOption::VALUE_OPTIONAL, 'Path to a csv file to aggregate multiple centers into a single alias')
-            ->addOption('dry-run', null, InputOption::VALUE_OPTIONAL, 'Do not commit the changes')
+            ->addOption('dry-run', null, InputOption::VALUE_NONE, 'Do not commit the changes')
+            ->addOption('csv-dump', null, InputOption::VALUE_REQUIRED, 'A path to dump a summary of the created file')
         ;
     }
 
@@ -127,15 +135,43 @@ class ChillImportUsersCommand extends ContainerAwareCommand
         $this->tempOutput = $output;
         $this->tempInput = $input;
         
-        if ($input->hasOption('dry-run')) {
+        if ($input->getOption('dry-run')) {
             $this->doChanges = false;
         }
+              
+        $this->prepareWriter();
         
         if ($input->hasOption('grouping-centers')) {
             $this->prepareGroupingCenters();
         }
         
-        $this->loadUsers();
+        try {
+            $this->loadUsers();
+        }
+        catch(\Exception $e) {
+            throw $e;
+        }
+    }
+    
+    protected function prepareWriter()
+    {
+        $this->output = $output = Writer::createFromPath($this->tempInput
+            ->getOption('csv-dump'), 'a+');
+        
+        $output->insertOne([
+            'email',
+            'username',
+            'id'
+        ]);
+    }
+    
+    protected function appendUserToFile(User $user)
+    {
+        $this->output->insertOne( [
+            $user->getEmail(),
+            $user->getUsername(),
+            $user->getId()
+            ]);
     }
     
     protected function loadUsers()
@@ -150,7 +186,7 @@ class ChillImportUsersCommand extends ContainerAwareCommand
             
             if ($this->doesUserExists($r)) {
                 $this->tempOutput->writeln(sprintf("User with username '%s' already "
-                    . "exists, skipping"));
+                    . "exists, skipping", $r["username"]));
                 
                 $this->logger->info("One user already exists, skipping creation", [
                     'username_in_file' => $r['username'],
@@ -161,7 +197,8 @@ class ChillImportUsersCommand extends ContainerAwareCommand
                 continue;
             }
             
-            $this->createUser($line, $r);
+            $user = $this->createUser($line, $r);
+            $this->appendUserToFile($user);
         }
     }
     
@@ -182,8 +219,8 @@ class ChillImportUsersCommand extends ContainerAwareCommand
     {
         $user = new User();
         $user
-            ->setEmail($data['email'])
-            ->setUsername($data['username'])
+            ->setEmail(\trim($data['email']))
+            ->setUsername(\trim($data['username']))
             ->setEnabled(true)
             ->setPassword($this->passwordEncoder->encodePassword($user, 
                 \bin2hex(\random_bytes(32))))
@@ -206,14 +243,18 @@ class ChillImportUsersCommand extends ContainerAwareCommand
         
         foreach($pgs as $pg) {
             foreach ($centers as $center) {
-                $user->addGroupCenter($this->createOrGetGroupCenter($center, $pg));
+                $groupcenter = $this->createOrGetGroupCenter($center, $pg);
+                
+                if (FALSE === $user->getGroupCenters()->contains($groupcenter)) {
+                    $user->addGroupCenter($groupcenter);
+                }
             }
         }
         
 
         if ($this->doChanges) {
             $this->em->persist($user);
-            $this->flush();
+            $this->em->flush();
         }
                         
         $this->logger->notice("Create user", [
@@ -222,6 +263,7 @@ class ChillImportUsersCommand extends ContainerAwareCommand
             'nb_of_groupCenters' => $user->getGroupCenters()->count()
         ]);
 
+        return $user;
     }
     
     protected function getPermissionGroup($alias)
@@ -343,6 +385,9 @@ class ChillImportUsersCommand extends ContainerAwareCommand
      */
     protected function getCenters($name)
     {
+        // sanitize
+        $name = \trim($name);
+        
         if (\array_key_exists($name, $this->centers)) {
             return $this->centers[$name];
         }