diff --git a/classes/responsetype/responsetype.php b/classes/responsetype/responsetype.php
index aa9c5dd2..841ea11d 100644
--- a/classes/responsetype/responsetype.php
+++ b/classes/responsetype/responsetype.php
@@ -287,6 +287,7 @@ protected function user_fields_sql() {
             $userfieldsarr = get_all_user_name_fields();
         }
         $userfieldsarr = array_merge($userfieldsarr, ['username', 'department', 'institution']);
+        $userfieldsarr = array_merge($userfieldsarr, ['username', 'department', 'institution', 'idnumber']);
         $userfields = '';
         foreach ($userfieldsarr as $field) {
             $userfields .= $userfields === '' ? '' : ', ';
diff --git a/lang/en/questionnaire.php b/lang/en/questionnaire.php
index a5ab2e7e..d6c2d1ab 100644
--- a/lang/en/questionnaire.php
+++ b/lang/en/questionnaire.php
@@ -259,7 +259,8 @@
 $string['gradesdeleted'] = 'Questionnaire grades deleted';
 $string['headingtext'] = 'Heading text';
 $string['horizontal'] = 'Horizontal';
-$string['id'] = 'ID';
+$string['id'] = 'User id';
+$string['useridnumber'] = 'User idnumber';
 $string['includerankaverages'] = 'Include rank question averages';
 $string['includechoicecodes'] = 'Include choice codes';
 $string['includechoicetext'] = 'Include choice text';
diff --git a/questionnaire.class.php b/questionnaire.class.php
index 5fd3bebe..e72f7841 100644
--- a/questionnaire.class.php
+++ b/questionnaire.class.php
@@ -3012,6 +3012,7 @@ protected function user_fields() {
             $userfieldsarr = get_all_user_name_fields();
         }
         $userfieldsarr = array_merge($userfieldsarr, ['username', 'department', 'institution']);
+        $userfieldsarr = array_merge($userfieldsarr, ['username', 'department', 'institution', 'idnumber']);
         return $userfieldsarr;
     }
 
@@ -3182,6 +3183,9 @@ protected function process_csv_row(array &$row,
         if (in_array('id', $options)) {
             array_push($positioned, $uid);
         }
+        if (in_array('useridnumber', $options)) {
+            array_push($positioned, $user->idnumber);
+        }
         if (in_array('fullname', $options)) {
             array_push($positioned, $fullname);
         }
@@ -3241,7 +3245,7 @@ public function generate_csv($currentgroupid, $rid='', $userid='', $choicecodes=
         $columns = array();
         $types = array();
         foreach ($options as $option) {
-            if (in_array($option, array('response', 'submitted', 'id'))) {
+            if (in_array($option, array('response', 'submitted', 'id', 'useridnumber'))) {
                 $columns[] = get_string($option, 'questionnaire');
                 $types[] = 0;
             } else if ($option == 'useridentityfields') {
diff --git a/settings.php b/settings.php
index 6a21c51d..32c37b31 100644
--- a/settings.php
+++ b/settings.php
@@ -42,6 +42,7 @@
         'course' => get_string('course'),
         'group' => get_string('group'),
         'id' => get_string('id', 'questionnaire'),
+        'useridnumber' => get_string('useridnumber', 'questionnaire'),
         'fullname' => get_string('fullname'),
         'username' => get_string('username'),
         'useridentityfields' => get_string('showuseridentity', 'admin')
diff --git a/tests/csvexport_test.php b/tests/csvexport_test.php
index bf90dbef..f594ee7c 100644
--- a/tests/csvexport_test.php
+++ b/tests/csvexport_test.php
@@ -199,7 +199,7 @@ private function do_test_csvexport_identity_fields($course, $cm, $user, $roleid,
      * @return string[]
      */
     private function expected_complete_output() {
-        return ["Institution	Department	Course	Group	Full name	Username	Q01_Text Box 1000	Q02_Essay Box 1002	" .
+        return ["Institution	Department	Course	Group	User idnumber	Full name	Username	Q01_Text Box 1000	Q02_Essay Box 1002	" .
             "Q03_Numeric 1004	Q04_Date 1006	Q05_Radio Buttons 1008	Q06_Drop Down 1010	Q07_Check Boxes 1012->four	" .
             "Q07_Check Boxes 1012->five	Q07_Check Boxes 1012->six	Q07_Check Boxes 1012->seven	Q07_Check Boxes 1012->eight	" .
             "Q07_Check Boxes 1012->nine	Q07_Check Boxes 1012->ten	Q07_Check Boxes 1012->eleven	" .
@@ -207,13 +207,13 @@ private function expected_complete_output() {
             "Q08_Rate Scale 1014->fifteen	Q08_Rate Scale 1014->sixteen	Q08_Rate Scale 1014->seventeen	" .
             "Q08_Rate Scale 1014->eighteen	Q08_Rate Scale 1014->nineteen	Q08_Rate Scale 1014->twenty	" .
             "Q08_Rate Scale 1014->happy	Q08_Rate Scale 1014->sad	Q08_Rate Scale 1014->jealous	Q09_Slider 1016",
-            "		Test course 1		Testy Lastname1	username1	Test answer	Some header textSome paragraph text	83	" .
+            "		Test course 1			Testy Lastname1	username1	Test answer	Some header textSome paragraph text	83	" .
             "27/12/2017	wind	three	0	0	0	0	0	0	0	0	0	1	1	2	3	4	5	1	2	3	4		5",
-            "		Test course 1		Testy Lastname2	username2	Test answer	Some header textSome paragraph text	83	" .
+            "		Test course 1			Testy Lastname2	username2	Test answer	Some header textSome paragraph text	83	" .
             "27/12/2017	wind	three	0	0	0	0	0	0	0	0	0	1	1	2	3	4	5	1	2	3	4		5",
-            "		Test course 1		Testy Lastname3	username3	Test answer	Some header textSome paragraph text	83	" .
+            "		Test course 1			Testy Lastname3	username3	Test answer	Some header textSome paragraph text	83	" .
             "27/12/2017	wind	three	0	0	0	0	0	0	0	0	0	1	1	2	3	4	5	1	2	3	4		5",
-            "		Test course 1		Testy Lastname4	username4	Test answer	Some header textSome paragraph text	83	" .
+            "		Test course 1			Testy Lastname4	username4	Test answer	Some header textSome paragraph text	83	" .
             "27/12/2017	wind	three	0	0	0	0	0	0	0	0	0	1	1	2	3	4	5	1	2	3	4		5"];
     }
 
@@ -222,7 +222,7 @@ private function expected_complete_output() {
      * @return string[]
      */
     private function expected_incomplete_output() {
-        return ["Institution	Department	Course	Group	Full name	Username	Complete	Q01_Text Box 1000	" .
+        return ["Institution	Department	Course	Group	User idnumber	Full name	Username	Complete	Q01_Text Box 1000	" .
             "Q02_Essay Box 1002	" .
             "Q03_Numeric 1004	Q04_Date 1006	Q05_Radio Buttons 1008	Q06_Drop Down 1010	Q07_Check Boxes 1012->four	" .
             "Q07_Check Boxes 1012->five	Q07_Check Boxes 1012->six	Q07_Check Boxes 1012->seven	Q07_Check Boxes 1012->eight	" .
@@ -231,15 +231,15 @@ private function expected_incomplete_output() {
             "Q08_Rate Scale 1014->fifteen	Q08_Rate Scale 1014->sixteen	Q08_Rate Scale 1014->seventeen	" .
             "Q08_Rate Scale 1014->eighteen	Q08_Rate Scale 1014->nineteen	Q08_Rate Scale 1014->twenty	" .
             "Q08_Rate Scale 1014->happy	Q08_Rate Scale 1014->sad	Q08_Rate Scale 1014->jealous	Q09_Slider 1016",
-            "		Test course 1		Testy Lastname1	username1	y	Test answer	Some header textSome paragraph text	83	" .
+            "		Test course 1			Testy Lastname1	username1	y	Test answer	Some header textSome paragraph text	83	" .
             "27/12/2017	wind	three	0	0	0	0	0	0	0	0	0	1	1	2	3	4	5	1	2	3	4		5",
-            "		Test course 1		Testy Lastname2	username2	y	Test answer	Some header textSome paragraph text	83	" .
+            "		Test course 1			Testy Lastname2	username2	y	Test answer	Some header textSome paragraph text	83	" .
             "27/12/2017	wind	three	0	0	0	0	0	0	0	0	0	1	1	2	3	4	5	1	2	3	4		5",
-            "		Test course 1		Testy Lastname3	username3	y	Test answer	Some header textSome paragraph text	83	" .
+            "		Test course 1			Testy Lastname3	username3	y	Test answer	Some header textSome paragraph text	83	" .
             "27/12/2017	wind	three	0	0	0	0	0	0	0	0	0	1	1	2	3	4	5	1	2	3	4		5",
-            "		Test course 1		Testy Lastname4	username4	y	Test answer	Some header textSome paragraph text	83	" .
+            "		Test course 1			Testy Lastname4	username4	y	Test answer	Some header textSome paragraph text	83	" .
             "27/12/2017	wind	three	0	0	0	0	0	0	0	0	0	1	1	2	3	4	5	1	2	3	4		5",
-            "		Test course 1		Testy Lastname5	username5	n	Test answer	Some header textSome paragraph text	83	" .
+            "		Test course 1			Testy Lastname5	username5	n	Test answer	Some header textSome paragraph text	83	" .
             "27/12/2017	wind	three	0	0	0	0	0	0	0	0	0	1	1	2	3	4	5	1	2	3	4		5"];
     }
 }