Make billing details optional for Paid Memberships Pro

billing-fields-optional.php

<?php
//add lines 4-15 to your custom plugin or functions.php of your active theme

function pmpro_remove_bfields( $pmpro_required_billing_fields ){

    //remove field ID's from array to make fields required
    $remove_field = array('bfirstname', 'blastname', 'baddress1', 'bcity', 'bstate', 'bcountry', 'bzipcode', 'bphone', 'bemail', 'bconfirmemail');

    //loop through the $remove_field array and unset each billing field to make it optional.
    foreach($remove_field as $field){
        unset($pmpro_required_billing_fields[$field]);
    }            

    return $pmpro_required_billing_fields;
}

add_filter('pmpro_required_billing_fields', 'pmpro_remove_bfields');

For the "Paid Memberships Pro - Address For Free Levels Add On", you may need to increase the priority of the code to be 50+

For example:

add_filter('pmpro_required_billing_fields', 'pmpro_remove_bfields', 50);