diff --git a/htdocs/societe.class.php b/htdocs/societe.class.php
index 8c78b51560f..2d672f0e130 100644
--- a/htdocs/societe.class.php
+++ b/htdocs/societe.class.php
@@ -324,7 +324,7 @@ class Societe {
 	      $nom = preg_replace("/[[:punct:]]/","",$this->db->result(0,0));
 	      $this->db->free();
 	      
-	      $prefix = strtoupper(substr($nom, 0, 2));
+	      $prefix = strtoupper(substr($nom, 0, 4));
       
 	      $sql = "SELECT count(*) FROM ".MAIN_DB_PREFIX."societe WHERE prefix_comm = '$prefix'";
 	      if ( $this->db->query( $sql) )