diff --git a/Application/Model/AbstractClasses/pdfdocumentsGeneric.php b/Application/Model/AbstractClasses/pdfdocumentsGeneric.php
index b2b9292..9009880 100644
--- a/Application/Model/AbstractClasses/pdfdocumentsGeneric.php
+++ b/Application/Model/AbstractClasses/pdfdocumentsGeneric.php
@@ -36,9 +36,14 @@ abstract class pdfdocumentsGeneric extends Base implements genericInterface
     const PDF_ORIENTATION_PORTRAIT = 'P';
     const PDF_ORIENTATION_LANDSCAPE = 'L';
 
+    public $filenameExtension = 'pdf';
+
     /** @var Smarty  */
     public $oSmarty;
 
+    /** @var string */
+    public $filename;
+
     /**
      * pdfDocumentsGeneric constructor.
      */
@@ -126,6 +131,45 @@ abstract class pdfdocumentsGeneric extends Base implements genericInterface
         return [self::PDF_ORIENTATION_PORTRAIT, 'A4', 'de'];
     }
 
+    /**
+     * @param $filename
+     */
+    public function setFilename($filename)
+    {
+        $this->filename = $filename;
+    }
+
+    /**
+     * @param string $sFilename
+     *
+     * @return string
+     */
+    public function getFilename()
+    {
+        // forced filename from setFilename()
+        if ($this->filename) {
+            return $this->addFilenameExtension($this->filename);
+        }
+
+        return $this->addFilenameExtension($this->getTypeForFilename());
+    }
+
+    /**
+     * @param string $filename
+     *
+     * @return string
+     */
+    public function addFilenameExtension($filename)
+    {
+        $extension = $this->filenameExtension;
+        $extensionLength = (strlen($extension) + 1) * -1;
+        if ((bool) strlen($extension) && substr($filename, $extensionLength) != '.'.$extension) {
+            $filename .= '.'.$extension;
+        }
+
+        return $filename;
+    }
+
     /**
      * Gets proper file name
      *
diff --git a/Application/Model/AbstractClasses/pdfdocumentsOrder.php b/Application/Model/AbstractClasses/pdfdocumentsOrder.php
index b719dd8..78b3b62 100644
--- a/Application/Model/AbstractClasses/pdfdocumentsOrder.php
+++ b/Application/Model/AbstractClasses/pdfdocumentsOrder.php
@@ -66,15 +66,22 @@ abstract class pdfdocumentsOrder extends pdfdocumentsGeneric implements orderInt
      */
     public function getFilename()
     {
+        // forced filename from setFilename()
+        if ($this->filename) {
+            return $this->addFilenameExtension($this->filename);
+        }
+
         $sTrimmedBillName = trim($this->getOrder()->getFieldData('oxbilllname'));
 
-        return implode(
-            '_',
-            [
-                $this->getTypeForFilename(),
-                $this->getOrder()->getFieldData('oxordernr'),
-                $sTrimmedBillName . ".pdf"
-            ]
+        return $this->addFilenameExtension(
+            implode(
+                '_',
+                [
+                    $this->getTypeForFilename(),
+                    $this->getOrder()->getFieldData('oxordernr'),
+                    $sTrimmedBillName
+                ]
+            )
         );
     }
 
diff --git a/Application/Model/Interfaces/pdfdocumentsGenericInterface.php b/Application/Model/Interfaces/pdfdocumentsGenericInterface.php
index acc0751..a57fa81 100644
--- a/Application/Model/Interfaces/pdfdocumentsGenericInterface.php
+++ b/Application/Model/Interfaces/pdfdocumentsGenericInterface.php
@@ -56,8 +56,20 @@ interface pdfdocumentsGenericInterface
      */
     public function genPdf($sFilename, $iSelLang = 0, $target = 'I');
 
+    /**
+     * @param string $filename
+     */
+    public function setFilename($filename);
+
     /**
      * @return string
      */
     public function getFilename();
+
+    /**
+     * @param string $filename
+     *
+     * @return string
+     */
+    public function addFilenameExtension($filename);
 }
\ No newline at end of file