woocommerce/templates/notices/success.php

<?php
/**
 * Show messages
 *
 * This template can be overridden by copying it to yourtheme/woocommerce/notices/success.php
 *
 * HOWEVER, on occasion WooCommerce will need to update template files and you (the theme developer)
 * will need to copy the new files to your theme to maintain compatibility. We try to do this
 * as little as possible, but it does happen. When this occurs the version of the template file will
 * be bumped and the readme will list any important changes.
 *
 * @see 	    http://docs.woothemes.com/document/template-structure/
 * @author 		WooThemes
 * @package 	WooCommerce/Templates
 * @version     1.6.4
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly
}

if ( ! $messages ){
	return;
}

?>

<?php foreach ( $messages as $message ) : ?>
	<div class="woocommerce-message"><?php echo wp_kses_post( $message ); ?></div>
<?php endforeach; ?>