If your package was marked as undeliverable by UPS, it will be held at UPS location for couple of days and then most likely be returned to us. Once we physically receive the package, we will notify you. If the package was undeliverable due to incorrect address provided by you, you are responsible for shipping cost to reship the package. If the package was undeliverable due to Nails A to Z's fault, we will ship out the package again as soon as we find out that the original package is coming back to us, at no cost to you. If you do not want the package anymore, we can issue you a refund for your order minus the original shipping.