USPS Customs Form customs form https://cns.usps.com/go/ShippingInformationAction_input USPS.com website Customs Form 2976A (online form) USPS Customs Form Customs Form Customs Form https://cns.usps.com/go/ShippingInformationAction_input https://cns.usps.com/go/ShippingInformationAction_input