WooCommerce - Change Sort Code to BSB

functions.php

<?php
/**
 * Rename WooCommmerce's "Sort Code" to "BSB". Useful for Australian stores
 * Ref: https://gist.github.com/om4james/9885791
 */
function woocommerce_sort_code_rename_to_bsb($translation, $text, $domain) {
    if ($domain == 'woocommerce') {
        switch ($text) {
            case 'Sort Code':
                $translation = 'BSB';
                break;

        }
    }

    return $translation;
}
add_filter('gettext', 'woocommerce_sort_code_rename_to_bsb', 10, 3);