We're sorry, but we cannot add a signature requirement once your package has shipped. What we can do to ensure that your package will not be delivered and left unattended is reroute your shipment to a UPS partner location to be held for the recipient to pick up. Please contact our Support Team to request a reroute. There is no fee for rerouting your shipment to a UPS Customer Center, but you will be charged a $18 fee for reroutes to other UPS locations.