diff --git a/class/zugferdimport.class.php b/class/zugferdimport.class.php
index bfdda55..1f93a9f 100755
--- a/class/zugferdimport.class.php
+++ b/class/zugferdimport.class.php
@@ -675,12 +675,12 @@ class ZugferdImport extends CommonObject
             $this->status = self::STATUS_IMPORTED;
         }
 
-        // Copy PDF to documents
-        $destdir = $conf->importzugferd->dir_output . '/imports';
+        // Copy PDF to documents (in subfolder by import ID)
+        $destdir = $conf->importzugferd->dir_output . '/imports/' . $this->id;
         if (!is_dir($destdir)) {
             dol_mkdir($destdir);
         }
-        $destfile = $destdir . '/' . $this->ref . '_' . basename($file_path);
+        $destfile = $destdir . '/' . $this->pdf_filename;
         copy($file_path, $destfile);
 
         // Update status