Re-order WooCommerce Checkout Fields

functions.php

<?php
/*
 * Re-order Checkout Fields
 */
 
add_filter( 'woocommerce_checkout_fields', 'rez_move_checkout_fields' );
  
function rez_move_checkout_fields( $fields ) {
     
  $fields2['billing']['billing_email']      = $fields['billing']['billing_email'];
  $fields2['billing']['billing_first_name'] = $fields['billing']['billing_first_name'];
  $fields2['billing']['billing_last_name']  = $fields['billing']['billing_last_name'];
  $fields2['billing']['billing_company']    = $fields['billing']['billing_company'];
  $fields2['billing']['billing_address_1']  = $fields['billing']['billing_address_1'];
  $fields2['billing']['billing_address_2']  = $fields['billing']['billing_address_2'];
  $fields2['billing']['billing_city']       = $fields['billing']['billing_city'];
  $fields2['billing']['billing_postcode']   = $fields['billing']['billing_postcode'];
  $fields2['billing']['billing_state']      = $fields['billing']['billing_state'];
  $fields2['billing']['billing_country']    = $fields['billing']['billing_country'];
  $fields2['billing']['billing_phone']      = $fields['billing']['billing_phone'];
     
  // Shipping: move these around in the order you'd like
     
  $fields2['shipping']['shipping_first_name'] = $fields['shipping']['shipping_first_name'];
  $fields2['shipping']['shipping_last_name']  = $fields['shipping']['shipping_last_name'];
  $fields2['shipping']['shipping_company']    = $fields['shipping']['shipping_company'];
  $fields2['shipping']['shipping_address_1']  = $fields['shipping']['shipping_address_1'];
  $fields2['shipping']['shipping_address_2']  = $fields['shipping']['shipping_address_2'];
  $fields2['shipping']['shipping_city']       = $fields['shipping']['shipping_city'];
  $fields2['shipping']['shipping_postcode']   = $fields['shipping']['shipping_postcode'];
  $fields2['shipping']['shipping_state']      = $fields['shipping']['shipping_state'];
  $fields2['shipping']['shipping_country']    = $fields['shipping']['shipping_country'];
     
  return $fields2;
}