re-order WooCommerce Checkout Fields

reorder-checkout.php

add_filter( 'woocommerce_checkout_fields', 'custom_move_checkout_fields' );

function custom_move_checkout_fields( $fields ) {

	// Lets display the email first. You can move these around depending on your needs.
	$billing_order = array(
		"billing_email",
		"billing_first_name", 
		"billing_last_name", 
		"billing_company", 
		"billing_address_1", 
		"billing_address_2", 
		"billing_postcode", 
		"billing_country",
		"billing_state",
		"billing_phone"
	);

	// This makes sure above orders are maintained.
	foreach($billing_order as $billing_field) {
	    $billing_fields[$billing_field] = $fields["billing"][$billing_field];
	}

	$fields["billing"] = $billing_fields;

	// Re-order this according to your need.
	$shipping_order = array(
		"shipping_first_name", 
		"shipping_last_name", 
		"shipping_company", 
		"shipping_address_1", 
		"shipping_address_2", 
		"shipping_postcode", 
		"shipping_country",
		"shipping_city",
		"shipping_state"
	);

	// This makes sure above orders are maintained.
	foreach($shipping_order as $shipping_field) {
	    $shipping_fields[$shipping_field] = $fields["shipping"][$shipping_field];
	}

	$fields["shipping"] = $shipping_fields;

	return $fields;
}