diff --git a/admin/user/user_bulk.php b/admin/user/user_bulk.php
index 751a75b5798..90aeb021fe6 100644
--- a/admin/user/user_bulk.php
+++ b/admin/user/user_bulk.php
@@ -1,4 +1,26 @@
 <?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Bulk user actions
+ *
+ * @package    core
+ * @copyright  Moodle
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
 
 require_once('../../config.php');
 require_once($CFG->libdir.'/adminlib.php');
@@ -10,28 +32,23 @@ admin_externalpage_setup('userbulk');
 if (!isset($SESSION->bulk_users)) {
     $SESSION->bulk_users = array();
 }
-// create the user filter form
+// Create the user filter form.
 $ufiltering = new user_filtering();
 
-// array of bulk operations
-// create the bulk operations form
-$action_form = new user_bulk_action_form();
-if ($data = $action_form->get_data()) {
-    // check if an action should be performed and do so
-    switch ($data->action) {
-        case 1: redirect($CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk_confirm.php');
-        case 2: redirect($CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk_message.php');
-        case 3: redirect($CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk_delete.php');
-        case 4: redirect($CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk_display.php');
-        case 5: redirect($CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk_download.php');
-        case 7: redirect($CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk_forcepasswordchange.php');
-        case 8: redirect($CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk_cohortadd.php');
+// Create the bulk operations form.
+$actionform = new user_bulk_action_form();
+if ($data = $actionform->get_data()) {
+    // Check if an action should be performed and do so.
+    $bulkactions = $actionform->get_actions();
+    if (array_key_exists($data->action, $bulkactions)) {
+        redirect($bulkactions[$data->action]->url);
     }
+
 }
 
-$user_bulk_form = new user_bulk_form(null, get_selection_data($ufiltering));
+$userbulkform = new user_bulk_form(null, get_selection_data($ufiltering));
 
-if ($data = $user_bulk_form->get_data()) {
+if ($data = $userbulkform->get_data()) {
     if (!empty($data->addall)) {
         add_selection_all($ufiltering);
 
@@ -40,7 +57,7 @@ if ($data = $user_bulk_form->get_data()) {
             if (in_array(0, $data->ausers)) {
                 add_selection_all($ufiltering);
             } else {
-                foreach($data->ausers as $userid) {
+                foreach ($data->ausers as $userid) {
                     if ($userid == -1) {
                         continue;
                     }
@@ -52,14 +69,14 @@ if ($data = $user_bulk_form->get_data()) {
         }
 
     } else if (!empty($data->removeall)) {
-        $SESSION->bulk_users= array();
+        $SESSION->bulk_users = array();
 
     } else if (!empty($data->removesel)) {
         if (!empty($data->susers)) {
             if (in_array(0, $data->susers)) {
-                $SESSION->bulk_users= array();
+                $SESSION->bulk_users = array();
             } else {
-                foreach($data->susers as $userid) {
+                foreach ($data->susers as $userid) {
                     if ($userid == -1) {
                         continue;
                     }
@@ -69,18 +86,17 @@ if ($data = $user_bulk_form->get_data()) {
         }
     }
 
-    // reset the form selections
+    // Reset the form selections.
     unset($_POST);
-    $user_bulk_form = new user_bulk_form(null, get_selection_data($ufiltering));
+    $userbulkform = new user_bulk_form(null, get_selection_data($ufiltering));
 }
-// do output
 echo $OUTPUT->header();
 
 $ufiltering->display_add();
 $ufiltering->display_active();
 
-$user_bulk_form->display();
+$userbulkform->display();
 
-$action_form->display();
+$actionform->display();
 
 echo $OUTPUT->footer();
diff --git a/admin/user/user_bulk_forms.php b/admin/user/user_bulk_forms.php
index ee71a22f253..b9e543243df 100644
--- a/admin/user/user_bulk_forms.php
+++ b/admin/user/user_bulk_forms.php
@@ -1,34 +1,114 @@
 <?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Bulk user action forms
+ *
+ * @package    core
+ * @copyright  Moodle
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
 
 require_once($CFG->libdir.'/formslib.php');
 require_once($CFG->libdir.'/datalib.php');
 
+/**
+ * Bulk user action form
+ *
+ * @copyright  Moodle
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
 class user_bulk_action_form extends moodleform {
-    function definition() {
+
+    /**
+     * Returns an array of action_link's of all bulk actions available for this user.
+     *
+     * @return array of action_link objects
+     */
+    public function get_actions() : array {
+
+        global $CFG;
+
+        $syscontext = context_system::instance();
+        $actions = [];
+        if (has_capability('moodle/user:update', $syscontext)) {
+            $actions['confirm'] = new action_link(
+                new moodle_url('/admin/user/user_bulk_confirm.php'),
+                get_string('confirm'));
+        }
+        if (has_capability('moodle/site:readallmessages', $syscontext) && !empty($CFG->messaging)) {
+            $actions['message'] = new action_link(
+                new moodle_url('/admin/user/user_bulk_message.php'),
+                get_string('messageselectadd'));
+        }
+        if (has_capability('moodle/user:delete', $syscontext)) {
+            $actions['delete'] = new action_link(
+                new moodle_url('/admin/user/user_bulk_delete.php'),
+                get_string('delete'));
+        }
+        $actions['displayonpage'] = new action_link(
+                new moodle_url('/admin/user/user_bulk_display.php'),
+                get_string('displayonpage'));
+
+        if (has_capability('moodle/user:update', $syscontext)) {
+            $actions['download'] = new action_link(
+                new moodle_url('/admin/user/user_bulk_download.php'),
+                get_string('download', 'admin'));
+        }
+
+        if (has_capability('moodle/user:update', $syscontext)) {
+            $actions['forcepasswordchange'] = new action_link(
+                new moodle_url('/admin/user/user_bulk_forcepasswordchange.php'),
+                get_string('forcepasswordchange'));
+        }
+        if (has_capability('moodle/cohort:assign', $syscontext)) {
+            $actions['addtocohort'] = new action_link(
+                new moodle_url('/admin/user/user_bulk_cohortadd.php'),
+                get_string('bulkadd', 'core_cohort'));
+        }
+
+        // Any plugin can append actions to this list by implementing a callback
+        // <component>_bulk_user_actions() which returns an array of action_link.
+        // Each new action's key should have a frankenstyle prefix to avoid clashes.
+        // See MDL-38511 for more details.
+        $moreactions = get_plugins_with_function('bulk_user_actions', 'lib.php');
+        foreach ($moreactions as $plugintype => $plugins) {
+            foreach ($plugins as $pluginfunction) {
+                $actions += $pluginfunction();
+            }
+        }
+
+        return $actions;
+
+    }
+
+    /**
+     * Form definition
+     */
+    public function definition() {
         global $CFG;
 
         $mform =& $this->_form;
 
-        $syscontext = context_system::instance();
-        $actions = array(0=>get_string('choose').'...');
-        if (has_capability('moodle/user:update', $syscontext)) {
-            $actions[1] = get_string('confirm');
-        }
-        if (has_capability('moodle/site:readallmessages', $syscontext) && !empty($CFG->messaging)) {
-            $actions[2] = get_string('messageselectadd');
-        }
-        if (has_capability('moodle/user:delete', $syscontext)) {
-            $actions[3] = get_string('delete');
-        }
-        $actions[4] = get_string('displayonpage');
-        if (has_capability('moodle/user:update', $syscontext)) {
-            $actions[5] = get_string('download', 'admin');
-        }
-        if (has_capability('moodle/user:update', $syscontext)) {
-            $actions[7] = get_string('forcepasswordchange');
-        }
-        if (has_capability('moodle/cohort:assign', $syscontext)) {
-            $actions[8] = get_string('bulkadd', 'core_cohort');
+        $actions = [0 => get_string('choose') . '...'];
+        $bulkactions = $this->get_actions();
+        foreach ($bulkactions as $key => $action) {
+            $actions[$key] = $action->text;
         }
         $objs = array();
         $objs[] =& $mform->createElement('select', 'action', null, $actions);
@@ -37,8 +117,18 @@ class user_bulk_action_form extends moodleform {
     }
 }
 
+/**
+ * Bulk user form
+ *
+ * @copyright  Moodle
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
 class user_bulk_form extends moodleform {
-    function definition() {
+
+    /**
+     * Form definition
+     */
+    public function definition() {
 
         $mform =& $this->_form;
         $acount =& $this->_customdata['acount'];
@@ -92,7 +182,6 @@ class user_bulk_form extends moodleform {
         $objs[1] =& $mform->createElement('select', 'susers', get_string('selected', 'bulkusers'), $schoices, 'size="15"');
         $objs[1]->setMultiple(true);
 
-
         $grp =& $mform->addElement('group', 'usersgrp', get_string('users', 'bulkusers'), $objs, ' ', false);
         $mform->addHelpButton('usersgrp', 'users', 'bulkusers');
 
diff --git a/lib/upgrade.txt b/lib/upgrade.txt
index c410cd08166..cf7bac61030 100644
--- a/lib/upgrade.txt
+++ b/lib/upgrade.txt
@@ -19,6 +19,7 @@ information provided here is intended especially for developers.
   - $plugin->incompatible = 36;
     incompatible takes a single int corresponding to the first incompatible branch. Any Moodle versions including and
     above this will be prevented from installing the plugin, and a message will be given when attempting installation.
+* Added the <component>_bulk_user_actions() callback which returns a list of custom action_links objects
 
 === 3.8 ===
 * Add CLI option to notify all cron tasks to stop: admin/cli/cron.php --stop