diff --git a/src/Controller/DefaultController.php b/src/Controller/DefaultController.php
index 2b52c1b..9dd06dc 100644
--- a/src/Controller/DefaultController.php
+++ b/src/Controller/DefaultController.php
@@ -321,12 +321,24 @@ class DefaultController extends AbstractController {
 		$data = $request->getContent();
 		$data = json_decode( $data, true );
 
-		$newOwner = new Owner();
-		$newOwner
-			->setEmail( $data[ 'email' ] )
-			->setPseudo( $data[ 'pseudo' ] );
+
+		$emOwner       = $this->getDoctrine()->getRepository( Owner::class );
+		$existingOwner = false;
+		$foundOwner    = $emOwner->findOneByEmail( trim( $data[ 'email' ] ) );
+		// manage existing or new Owner
+		if ( ! $foundOwner ) {
+			$foundOwner = new Owner();
+			$foundOwner
+				->setEmail( $data[ 'email' ] )
+				->setPseudo( $data[ 'pseudo' ] );
+		} else {
+			$existingOwner = true;
+		}
+		$foundOwner
+			->setModifierToken( $poll->generateAdminKey() );
 		$stack = new StackOfVotes();
 		$stack
+			->setOwner( $foundOwner )
 			->setPseudo( $data[ 'pseudo' ] )
 			->setPoll( $poll );
 		foreach ( $data[ 'votes' ] as $voteInfo ) {
@@ -354,11 +366,16 @@ class DefaultController extends AbstractController {
 		$em->persist( $stack );
 		$em->persist( $poll );
 		$em->flush();
+		$precision = '';
+		if ( $existingOwner ) {
+			$precision = ' from an existing owner : ' . $foundOwner->getEmail();
+		}
 
 		return $this->json( [
-			'message'       => 'you created a vote stack',
-			'vote_stack'    => $stack,
-			'json_you_sent' => $data,
+			'message'              => 'you created a vote stack' . $precision,
+			'vote_stack'           => $stack,
+			'owner_modifier_token' => $foundOwner->getModifierToken(),
+			'json_you_sent'        => $data,
 		],
 			201 );
 	}