diff --git a/export.php b/export.php
index 57d7ebc..13949e5 100644
--- a/export.php
+++ b/export.php
@@ -87,10 +87,12 @@ if ($mform->is_submitted()) {
         if (isset($formdata->ident['uname'])) {
             $data->tabhead[] = get_string('username');
         }
+        if (isset($formdata->ident['idnumber'])) {
+            $data->tabhead[] = get_string('idnumber');
+        }
         $data->tabhead[] = get_string('lastname');
         $data->tabhead[] = get_string('firstname');
 
-
         if (count($reportdata->sessions) > 0) {
             foreach ($reportdata->sessions as $sess) {
                 $text = userdate($sess->sessdate, get_string('strftimedmyhm', 'attendance'));
@@ -114,6 +116,9 @@ if ($mform->is_submitted()) {
             if (isset($formdata->ident['uname'])) {
                 $data->table[$i][] = $user->username;
             }
+            if (isset($formdata->ident['idnumber'])) {
+                $data->table[$i][] = $user->idnumber;
+            }
             $data->table[$i][] = $user->lastname;
             $data->table[$i][] = $user->firstname;
             $cellsgenerator = new user_sessions_cells_text_generator($reportdata, $user);
diff --git a/export_form.php b/export_form.php
index e43e1c6..5ec04f1 100644
--- a/export_form.php
+++ b/export_form.php
@@ -62,13 +62,14 @@ class mod_attendance_export_form extends moodleform {
 
         $ident = array();
         $ident[] =& $mform->createElement('checkbox', 'id', '', get_string('studentid', 'attendance'));
-
         $ident[] =& $mform->createElement('checkbox', 'uname', '', get_string('username'));
+        $ident[] =& $mform->createElement('checkbox', 'idnumber', '', get_string('idnumber'));
         $mform->addGroup($ident, 'ident', get_string('identifyby', 'attendance'), array('<br />'), true);
-        $mform->setDefaults(array('ident[id]' => true, 'ident[uname]' => true));
+        $mform->setDefaults(array('ident[id]' => true, 'ident[uname]' => true, 'ident[idnumber]' => false));
         $mform->setType('id', PARAM_INT);
         $mform->setType('uname', PARAM_INT);
-
+        $mform->setType('idnumber', PARAM_NOTAGS);
+        
         $mform->addElement('checkbox', 'includeallsessions', get_string('includeall', 'attendance'), get_string('yes'));
         $mform->setDefault('includeallsessions', true);
         $mform->addElement('checkbox', 'includenottaken', get_string('includenottaken', 'attendance'), get_string('yes'));
diff --git a/locallib.php b/locallib.php
index cda5fc5..5fa8fd6 100644
--- a/locallib.php
+++ b/locallib.php
@@ -962,12 +962,12 @@ class attendance {
         global $DB;
 
         // Fields we need from the user table.
-        $userfields = user_picture::fields('u').',u.username';
+        $userfields = user_picture::fields('u').',u.username,u.idnumber';
 
         if (isset($this->pageparams->sort) and ($this->pageparams->sort == ATT_SORT_FIRSTNAME)) {
-            $orderby = "u.firstname ASC, u.lastname ASC";
+            $orderby = "u.firstname ASC, u.lastname ASC, u.idnumber ASC";
         } else {
-            $orderby = "u.lastname ASC, u.firstname ASC";
+            $orderby = "u.lastname ASC, u.firstname ASC, u.idnumber ASC";
         }
 
         $users = get_enrolled_users($this->context, 'mod/attendance:canbelisted', $groupid, $userfields, $orderby);