Remove the Registration ID and replace it with a custom one

EE reg id

//This goes in the custon files add on

// remove default registration id filter
function my_remove_registration_id_filter() {
    remove_filter('filter_hook_espresso_registration_id', 'espresso_build_registration_id', 10);
}

add_filter ('filter_hook_espresso_registration_id', 'my_remove_registration_id_filter', 9 );


function my_custom_registration_id(){
    $id = uniqid();
        // for the sake of an example, we'll convert the unique ID to be letters from the alphabet, which would make for something similar to an airline's reservation code
    return strtr($id, '01234567890', 'abcdefghij');
}

add_filter('filter_hook_espresso_registration_id', 'my_custom_registration_id', 10, 1);



// If you are running Ticketing you will need to edit the ticket functions.php file as well, approx line 126

//Make sure we have attendee data
if ($attendee_id=="0" || $registration_id=="0" || (!is_string($registration_id)))
     return;