diff --git a/group/externallib.php b/group/externallib.php
index 9ed2492e122..cb61dc8f0c6 100644
--- a/group/externallib.php
+++ b/group/externallib.php
@@ -1486,4 +1486,96 @@ class core_group_external extends external_api {
         );
     }
 
+    /**
+     * Returns description of method parameters
+     *
+     * @return external_function_parameters
+     * @since Moodle 3.6
+     */
+    public static function update_groups_parameters() {
+        return new external_function_parameters(
+            array(
+                'groups' => new external_multiple_structure(
+                    new external_single_structure(
+                        array(
+                            'id' => new external_value(PARAM_INT, 'ID of the group'),
+                            'name' => new external_value(PARAM_TEXT, 'multilang compatible name, course unique'),
+                            'description' => new external_value(PARAM_RAW, 'group description text', VALUE_OPTIONAL),
+                            'descriptionformat' => new external_format_value('description', VALUE_DEFAULT),
+                            'enrolmentkey' => new external_value(PARAM_RAW, 'group enrol secret phrase', VALUE_OPTIONAL),
+                            'idnumber' => new external_value(PARAM_RAW, 'id number', VALUE_OPTIONAL)
+                        )
+                    ), 'List of group objects. A group is found by the id, then all other details provided will be updated.'
+                )
+            )
+        );
+    }
+
+    /**
+     * Update groups
+     *
+     * @param array $groups
+     * @return null
+     * @since Moodle 3.6
+     */
+    public static function update_groups($groups) {
+        global $CFG, $DB;
+        require_once("$CFG->dirroot/group/lib.php");
+
+        $params = self::validate_parameters(self::update_groups_parameters(), array('groups' => $groups));
+
+        $transaction = $DB->start_delegated_transaction();
+
+        foreach ($params['groups'] as $group) {
+            $group = (object)$group;
+
+            if (trim($group->name) == '') {
+                throw new invalid_parameter_exception('Invalid group name');
+            }
+
+            if (! $currentgroup = $DB->get_record('groups', array('id' => $group->id))) {
+                throw new invalid_parameter_exception("Group $group->id does not exist");
+            }
+
+            // Check if the modified group name already exists in the course.
+            if ($group->name != $currentgroup->name and
+                    $DB->get_record('groups', array('courseid' => $currentgroup->courseid, 'name' => $group->name))) {
+                throw new invalid_parameter_exception('A different group with the same name already exists in the course');
+            }
+
+            $group->courseid = $currentgroup->courseid;
+
+            // Now security checks.
+            $context = context_course::instance($group->courseid);
+            try {
+                self::validate_context($context);
+            } catch (Exception $e) {
+                $exceptionparam = new sdtClass();
+                $exceptionparam->message = $e->getMessage();
+                $exceptionparam->courseid = $group->courseid;
+                throw new moodle_exception('errorcoursecontextnotvalid', 'webservice', '', $exceptionparam);
+            }
+            require_capability('moodle/course:managegroups', $context);
+
+            if (!empty($group->description)) {
+                $group->descriptionformat = external_validate_format($group->descriptionformat);
+            }
+
+            groups_update_group($group);
+        }
+
+        $transaction->allow_commit();
+
+        return null;
+    }
+
+    /**
+     * Returns description of method result value
+     *
+     * @return null
+     * @since Moodle 3.6
+     */
+    public static function update_groups_returns() {
+        return null;
+    }
 }
diff --git a/group/tests/externallib_test.php b/group/tests/externallib_test.php
index 287118e7b96..e1af7ca62dc 100644
--- a/group/tests/externallib_test.php
+++ b/group/tests/externallib_test.php
@@ -115,6 +115,85 @@ class core_group_externallib_testcase extends externallib_advanced_testcase {
         $froups = core_group_external::create_groups(array($group4));
     }
 
+    /**
+     * Test update_groups
+     *
+     * @expectedException required_capability_exception
+     */
+    public function test_update_groups() {
+        global $DB;
+
+        $this->resetAfterTest(true);
+
+        $course = self::getDataGenerator()->create_course();
+
+        $group1data = array();
+        $group1data['courseid'] = $course->id;
+        $group1data['name'] = 'Group Test 1';
+        $group1data['description'] = 'Group Test 1 description';
+        $group1data['descriptionformat'] = FORMAT_MOODLE;
+        $group1data['enrolmentkey'] = 'Test group enrol secret phrase';
+        $group1data['idnumber'] = 'TEST1';
+        $group2data = array();
+        $group2data['courseid'] = $course->id;
+        $group2data['name'] = 'Group Test 2';
+        $group2data['description'] = 'Group Test 2 description';
+        $group2data['idnumber'] = 'TEST2';
+
+        // Set the required capabilities by the external function.
+        $context = context_course::instance($course->id);
+        $roleid = $this->assignUserCapability('moodle/course:managegroups', $context->id);
+        $this->assignUserCapability('moodle/course:view', $context->id, $roleid);
+
+        // Create the test groups.
+        $group1 = self::getDataGenerator()->create_group($group1data);
+        $group2 = self::getDataGenerator()->create_group($group2data);
+
+        $group1data['id'] = $group1->id;
+        unset($group1data['courseid']);
+        $group2data['id'] = $group2->id;
+        unset($group2data['courseid']);
+
+        // No exceptions should be triggered.
+        $group1data['idnumber'] = 'CHANGED';
+        core_group_external::update_groups(array($group1data));
+        $group2data['description'] = 'Group Test 2 description CHANGED';
+        core_group_external::update_groups(array($group2data));
+
+        foreach ([$group1, $group2] as $group) {
+            $dbgroup = $DB->get_record('groups', array('id' => $group->id), '*', MUST_EXIST);
+            switch ($dbgroup->name) {
+                case $group1data['name']:
+                    $this->assertEquals($dbgroup->idnumber, $group1data['idnumber']);
+                    $groupdescription = $group1data['description'];
+                    break;
+                case $group2data['name']:
+                    $this->assertEquals($dbgroup->idnumber, $group2data['idnumber']);
+                    $groupdescription = $group2data['description'];
+                    break;
+                default:
+                    throw new moodle_exception('unknowngroupname');
+                    break;
+            }
+            $this->assertEquals($dbgroup->description, $groupdescription);
+        }
+
+        // Taken idnumber exception.
+        $group1data['idnumber'] = 'TEST2';
+        try {
+            $groups = core_group_external::update_groups(array($group1data));
+            $this->fail('Exception expected due to already existing idnumber.');
+        } catch (moodle_exception $e) {
+            $this->assertInstanceOf('moodle_exception', $e);
+            $this->assertEquals(get_string('idnumbertaken', 'error'), $e->getMessage());
+        }
+
+        // Call without required capability.
+        $group1data['idnumber'] = 'TEST1';
+        $this->unassignUserCapability('moodle/course:managegroups', $context->id, $roleid);
+        $groups = core_group_external::update_groups(array($group1data));
+    }
+
     /**
      * Test get_groups
      *
diff --git a/lib/db/services.php b/lib/db/services.php
index 4f41b1ca291..76e705f48cc 100644
--- a/lib/db/services.php
+++ b/lib/db/services.php
@@ -847,6 +847,14 @@ $functions = array(
         'description' => 'Updates existing groupings',
         'type' => 'write',
     ),
+    'core_group_update_groups' => array(
+        'classname' => 'core_group_external',
+        'methodname' => 'update_groups',
+        'classpath' => 'group/externallib.php',
+        'description' => 'Updates existing groups.',
+        'type' => 'write',
+        'capabilities' => 'moodle/course:managegroups'
+    ),
     'core_message_block_user' => array(
         'classname' => 'core_message_external',
         'methodname' => 'block_user',
diff --git a/version.php b/version.php
index bdfeda5c41a..9d63cbf0692 100644
--- a/version.php
+++ b/version.php
@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2018110300.00;              // YYYYMMDD      = weekly release date of this DEV branch.
+$version  = 2018110500.00;              // YYYYMMDD      = weekly release date of this DEV branch.
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.